Q. What wheel with a rope lifts heavy things easily?
Options: A pulley · A gear · A ramp · An axle
Answer: A pulley
A pulley changes the direction of force, and several together let you lift heavy things with little effort.
← Home · 📚 Study Notes › 🔬 Science
Forces, machines, light, and sound — answers and explanations for all 200 questions. Cover the answer, have a guess first, then check the explanation. Want to play it as a quiz? Try it at the Quiz Playground!
🍎 Q. What force makes a ball thrown up come back down?
Options: Your breath · Gravity · Wind · Magnet force
Answer: Gravity
The force of Earth pulling things toward it is called 'gravity'.
🧲 Q. What force makes magnets push or pull each other?
Options: Wind · Magnetic force · Electricity · Sound
Answer: Magnetic force
The force acting between magnets is called 'magnetic force'.
🛝 Q. Why do you slide right down a slide?
Options: Gravity · Magnetic force · Wind · A friend
Answer: Gravity
'Gravity' pulls you downward.
🔥 Q. What force stops an object from sliding where it touches the ground?
Options: Magnetic force · Air force · Gravity · Friction
Answer: Friction
The force resisting motion where surfaces touch is called 'friction'.
☀️ Q. What do we call the light and heat energy the Sun gives us?
Options: Sound energy · Electrical energy · Solar energy · Wind energy
Answer: Solar energy
Energy from the Sun is called 'solar energy'.
⚖️ Q. Which principle does a seesaw use?
Options: A ladder · A pulley · A lever · A wheel
Answer: A lever
A seesaw uses the 'lever' principle with a pivot point.
⛰️ Q. What energy does a high-up object have, ready to show as it falls?
Options: Heat energy · Potential energy · Sound energy · Light energy
Answer: Potential energy
The higher it is, the more 'potential energy' it has.
🚗 Q. What energy does a fast-moving object have?
Options: Kinetic energy · Electrical energy · Potential energy · Sound energy
Answer: Kinetic energy
The energy of a moving object is called 'kinetic energy'.
💡 Q. Which object turns electrical energy into light energy?
Options: Fan · Speaker · Light bulb · Refrigerator
Answer: Light bulb
A 'light bulb' turns electricity into light.
Q. What do we call pushing or pulling an object?
Options: Color · Sound · Light · Force
Answer: Force
Pushing and pulling are both forces!
Q. What force makes a ball thrown up come back down?
Options: Elasticity · Magnetic force · Gravity · Friction
Answer: Gravity
Gravity, the pull of the Earth!
Q. Which way does gravity pull things?
Options: Toward Earth's center (down) · Up · Backward · Sideways
Answer: Toward Earth's center (down)
That's why things fall down!
Q. What force makes you slide right down a slide?
Options: Magnetic force · Friction · Wind · Gravity
Answer: Gravity
Gravity! It's Earth pulling us down — on the Moon, where it's 1/6 as strong, you'd slide much slower.
Q. What force keeps an object from sliding where it touches the floor?
Options: Magnetic force · Gravity · Elastic force · Friction
Answer: Friction
Friction is why your shoes don't slip!
Q. Why is ice so slippery?
Options: It's a magnet · There's no gravity · The wind is strong · There's little friction
Answer: There's little friction
It's so smooth that friction is small!
Q. Why do car tires have grooves (tread)?
Options: To add friction so they don't slip · To make noise · To be lighter · To look nice
Answer: To add friction so they don't slip
The grooves boost friction and keep you safe!
Q. What force pulls iron to a magnet, or pushes two magnets apart?
Options: Friction · Elastic force · Magnetic force · Gravity
Answer: Magnetic force
A magnet's power — magnetic force!
Q. What happens between two like poles of magnets (N-N)?
Options: They push apart · They melt · They stick together · Nothing
Answer: They push apart
Like poles push each other away!
Q. What happens between two different poles of magnets (N-S)?
Options: They push apart · They explode · They pull together · Nothing
Answer: They pull together
Opposite poles snap together!
Q. What do we call the force that snaps a stretched rubber band back?
Options: Elastic force · Gravity · Magnetic force · Friction
Answer: Elastic force
Elastic force wants to return to the original shape!
Q. What happens when you press down a spring?
Options: It melts · It breaks · It springs back up (elasticity) · It stays put
Answer: It springs back up (elasticity)
Boing! That's elasticity!
Q. Which feels more gravity — a heavy object or a light one?
Options: Neither feels it · The light one · The heavy one · They're the same
Answer: The heavy one
The heavier it is, the more gravity pulls it!
Q. What force makes you feel light in water and makes things float?
Options: Friction · Gravity · Buoyancy · Magnetic force
Answer: Buoyancy
Buoyancy — water pushing up!
Q. What is connected to why big steel ships float on water?
Options: Magnetic force · Buoyancy · Sound · Elastic force
Answer: Buoyancy
Being hollow gives them lots of buoyancy!
Q. What can happen to an object when you apply force?
Options: It changes color · It only makes sound · It disappears · It moves or changes shape
Answer: It moves or changes shape
Force changes motion and shape!
Q. What energy does a high-up object have that turns into force as it falls?
Options: Sound energy · Kinetic energy · Chemical energy · Potential energy
Answer: Potential energy
The higher it is, the more potential energy!
Q. Which energy is greatest when a swing reaches its highest point?
Options: Potential energy · Sound energy · Light energy · Kinetic energy
Answer: Potential energy
At the top, potential energy is at its max!
Q. Why is a swing fastest as it passes the lowest point?
Options: It got heavier · The wind blew · Potential energy turned into kinetic energy · The ropes stretched
Answer: Potential energy turned into kinetic energy
The power of height becomes speed!
Q. What do we call how fast or slow something is?
Options: Speed · Temperature · Weight · Color
Answer: Speed
How fast something goes is its speed!
Q. If something covers the same distance in less time, it is...?
Options: Faster · Slower · Stopped · The same
Answer: Faster
Getting there sooner means it's faster!
Q. What is connected to why a runner can't stop suddenly?
Options: Magnetic force · Inertia · Buoyancy · Elasticity
Answer: Inertia
Inertia — the tendency to keep moving!
Q. Why do you lean backward when a bus suddenly starts?
Options: Because of inertia · Because of gravity · Because of magnets · Because of wind
Answer: Because of inertia
Your body wants to stay still — inertia!
Q. What happens the harder you kick a ball?
Options: It goes closer · It stops · It only goes up · It goes farther and faster
Answer: It goes farther and faster
More force means faster and farther!
Q. Why does a rolling ball stop?
Options: Because of light · Because of sound · Because of friction · Because there's no gravity
Answer: Because of friction
Friction with the ground and air stops it!
Q. What do we call tools like scissors and bottle openers that do big jobs with small force?
Options: A magnet · A lever (tool) · A battery · A thermometer
Answer: A lever (tool)
The lever principle saves your strength!
Q. What wheel tool with a rope lifts things from a well or flagpole?
Options: A pulley · A lever · A magnet · A scale
Answer: A pulley
A pulley! It changes the direction of force, and using several lets you lift heavy things with little effort.
Q. What tool lets you push heavy loads up a slope like a hill?
Options: A pulley · A magnet · An inclined plane (ramp) · A spring
Answer: An inclined plane (ramp)
A slope takes less effort!
Q. What round thing makes carts and cars roll easily?
Options: A lever · A wheel · A magnet · A spring
Answer: A wheel
A wheel! Rolling instead of dragging slashes the friction — this simple invention changed the world.
Q. What's the benefit of using wheels?
Options: Move things easily with little force · It gets slower · It gets heavier · It gets louder
Answer: Move things easily with little force
Rolling is much easier than dragging!
Q. Which tool's principle do scissors use?
Options: A lever · A wheel · A spring · A pulley
Answer: A lever
Two levers pivoting on the center screw!
Q. What is the light and heat energy the Sun gives us?
Options: Solar energy · Chemical energy · Sound energy · Electrical energy
Answer: Solar energy
Solar energy — the source of life!
Q. Which object turns electrical energy into light?
Options: Fan · Refrigerator · Light bulb · Speaker
Answer: Light bulb
A light bulb! Electricity flows through a thin wire, heats it, and it glows — today's LEDs shine bright on far less power.
Q. Which object turns electrical energy into sound?
Options: Refrigerator · Iron · Speaker · Light bulb
Answer: Speaker
A speaker! An electric signal shakes a magnet, and that shaking pushes air into sound for our ears.
Q. Which object turns electrical energy into heat?
Options: Fan · Electric iron · Light bulb · Speaker
Answer: Electric iron
A nice hot iron!
Q. Which object turns electrical energy into motion?
Options: Speaker · Fan · Iron · Light bulb
Answer: Fan
A fan! Electricity spins the motor, and the angled blades push air into a cool breeze.
Q. What do we call food turning into power (energy) in our body?
Options: Chemical energy → body energy · Electrical energy · Light energy · Sound energy
Answer: Chemical energy → body energy
The energy in your meal lets you run and play!
Q. What kind of energy is stored inside a battery?
Options: Potential energy · Sound energy · Light energy · Chemical energy
Answer: Chemical energy
Chemical energy! Substances inside react to send out electricity — when it dies, the reacting material has run out.
Q. What can energy do?
Options: Change color · Always stay the same · Change into other forms · Disappear
Answer: Change into other forms
It changes like light ↔ electricity ↔ heat!
Q. Rubbing your hands to warm them is which energy change?
Options: Light → sound · Sound → heat · Kinetic energy → heat energy · Electricity → light
Answer: Kinetic energy → heat energy
The rubbing motion becomes heat!
Q. What does solar power turn into electricity?
Options: Wind · Water · Coal · Sunlight
Answer: Sunlight
Sunlight! When light hits a solar cell, electricity flows — no fuel, no fumes.
Q. What force does wind power use to make electricity?
Options: Oil · Wind · Sound · Sunlight
Answer: Wind
Wind! Huge blades catch it and spin a generator — the same idea as a pinwheel.
Q. What force does hydro power use to make electricity?
Options: Falling water · Fire · Wind · Sunlight
Answer: Falling water
The force of water falling from a dam!
Q. What do we call energy we can use again and again, like solar and wind?
Options: Electricity · Fossil fuels · Disposable energy · Renewable energy
Answer: Renewable energy
Renewable energy never runs out!
Q. What's the problem with energy like oil and coal that runs out someday?
Options: It runs out and causes pollution · It's clean · It smells nice · It's endless
Answer: It runs out and causes pollution
That's why we need renewable energy!
Q. What do we call the path electricity flows through?
Options: A blood vessel · A circuit · A road · A waterway
Answer: A circuit
A circuit connects battery, wire, and bulb!
Q. What must a circuit be like for a bulb to light up?
Options: It must be wet · It must be hot · It must be connected without a break · It must be broken
Answer: It must be connected without a break
The path must connect for electricity to flow!
Q. What makes or stores electricity?
Options: A magnet · A spring · A battery · A thermometer
Answer: A battery
The battery that runs your toys!
Q. Which material carries electricity well?
Options: Rubber · Metal (copper) · Glass · Wood
Answer: Metal (copper)
The copper wire inside a cord!
Q. Which material blocks electricity and prevents shocks?
Options: Iron · Rubber and plastic · Silver · Copper
Answer: Rubber and plastic
The rubber wrapped around a wire!
Q. What kind of energy is lightning?
Options: Only heat · Only light · Electrical energy · Sound energy
Answer: Electrical energy
Powerful electricity built up in a cloud!
Q. Why shouldn't you touch electric appliances with wet hands?
Options: It makes noise · It dirties the device · Water carries electricity — shock danger · Your hands are slippery
Answer: Water carries electricity — shock danger
Water conducts electricity! Dangerous!
Q. What's a way to save electricity?
Options: Leave it on all day · Run the AC with the door open · Leave cords plugged in · Turn off unused lights and unplug
Answer: Turn off unused lights and unplug
Small habits save energy!
Q. Which tool uses a magnet and Earth's property to show direction?
Options: A thermometer · A compass · A magnifying glass · A scale
Answer: A compass
A compass! Earth itself is a giant magnet, so the needle always points north and south.
Q. Which part of a magnet is strongest?
Options: The middle · Both ends (the poles) · Nowhere · The whole surface
Answer: Both ends (the poles)
Clips stick best at the N and S ends!
Q. What happens if you rub an iron nail on a magnet?
Options: It melts · It becomes a weak magnet · Nothing · It breaks
Answer: It becomes a weak magnet
A nail can become a magnet too!
Q. What force does a fridge magnet use to hold up a note?
Options: Gravity · Buoyancy · Elastic force · Magnetic force
Answer: Magnetic force
Magnetic force sticks it to the steel door!
Q. How is sound made?
Options: By being heavy · By glowing · By an object vibrating · By being warm
Answer: By an object vibrating
Vibration makes sound!
Q. What happens to the sound if you hit a drum harder?
Options: Only higher · No sound · It gets louder · It gets quieter
Answer: It gets louder
A harder hit means bigger vibrations and a louder sound!
Q. What tool gathers sound and sends it far?
Options: A thermometer · A scale · A megaphone · A magnifying glass
Answer: A megaphone
A megaphone! It gathers sound that would scatter and aims it forward so it carries far.
Q. Which does NOT use light energy?
Options: Shadow play · Plant photosynthesis · Solar power · Warming hands at a heater
Answer: Warming hands at a heater
A heater is heat energy! The rest involve light.
Q. What dark area forms when an object blocks light?
Options: A shadow · A rainbow · Lightning · Sunset glow
Answer: A shadow
Block the light and you get a shadow!
Q. How do you make a shadow bigger?
Options: Move the light closer to the object · Move it away · Turn it off · Remove the object
Answer: Move the light closer to the object
The closer the light, the bigger the shadow!
Q. Which force explains why we wear seat belts?
Options: Magnetic force · Elasticity · Inertia (it holds you in a sudden stop) · Buoyancy
Answer: Inertia (it holds you in a sudden stop)
It stops inertia from flinging you forward!
Q. Why does a parachute come down slowly?
Options: There's no wind · Because of air resistance · There's no gravity · Because of magnets
Answer: Because of air resistance
The wide cloth catches lots of air resistance!
Q. What makes a bicycle go forward?
Options: Gravity · The force of pushing the pedals · Sound · Light
Answer: The force of pushing the pedals
Your leg power turns the wheels!
Q. What force stops a bike when you squeeze the brakes?
Options: Friction · Buoyancy · Magnetic force · Elastic force
Answer: Friction
The brake rubs the wheel to stop it!
Q. What explains a roller coaster racing down from up high?
Options: Potential energy turning into kinetic energy · Light energy · Magnetic force · Sound energy
Answer: Potential energy turning into kinetic energy
The energy of height becomes speed!
Q. Why does a ball thrown upward slow down and stop?
Options: Gravity resists its rise · The wind is strong · Because of magnets · It got heavier
Answer: Gravity resists its rise
Gravity keeps pulling it down!
Q. Which does NOT reduce the effort of moving something heavy?
Options: Use a pulley · Push it up a ramp · Just lift it with your hands · Use a cart with wheels
Answer: Just lift it with your hands
Tools make it much easier!
Q. What's good about saving energy?
Options: It gets noisy · It gets hot · It gets slow · It saves resources and protects the environment
Answer: It saves resources and protects the environment
Good for the planet and your wallet!
Q. Which of these is NOT a kind of force?
Options: Magnetic force · Gravity · Friction · Color
Answer: Color
Color! Gravity, friction, and magnetism push or pull objects, but color is just something you see.
Q. Which of these is NOT a kind of energy?
Options: Heat energy · Sound energy · Light energy · Weight
Answer: Weight
Weight! Light, heat, and electricity are energy, but weight is the size of Earth's pull on an object.
Q. A spinning fan changes which energy into which?
Options: Electricity → motion · Heat → light · Sound → electricity · Light → sound
Answer: Electricity → motion
Electricity becomes the blades' motion!
Q. What energy change happens when you turn on a flashlight?
Options: Electricity (chemical) → light · Light → sound · Sound → heat · Motion → electricity
Answer: Electricity (chemical) → light
The battery's energy becomes light!
Q. What force turns a water wheel?
Options: Wind · Magnets · Sunlight · The force of flowing (falling) water
Answer: The force of flowing (falling) water
Water power grinds the grain!
Q. What explains a balloon flying around as the air rushes out?
Options: The power of sound · Air goes backward and pushes it forward (action-reaction) · Magnetic force · The power of light
Answer: Air goes backward and pushes it forward (action-reaction)
Rockets fly on this same principle!
Q. What is most like the principle of a rocket blasting into the sky?
Options: Ice melting · A deflating balloon flying around · Magnets sticking · A swing swinging
Answer: A deflating balloon flying around
Blast gas downward to go up — action and reaction!
Q. What is the property where still things stay still and moving things keep moving?
Options: Buoyancy · Magnetic force · Inertia · Elasticity
Answer: Inertia
Newton's law of inertia!
Q. With the same push, which moves more easily?
Options: Neither moves · The lighter object · They're the same · The heavier object
Answer: The lighter object
The lighter it is, the easier it moves!
Q. What energy makes a hand warmer warm in winter?
Options: Sound energy · Heat energy · Light energy · Potential energy
Answer: Heat energy
A chemical change makes heat!
Q. Why does a dam hold water up high?
Options: To freeze the water · To make sound · To make light · To use the water's potential energy to make electricity
Answer: To use the water's potential energy to make electricity
Falling water's power generates electricity!
Q. Which idea is closest to 'it takes force to move'?
Options: Force and motion · Light and color · Sound and vibration · States of water
Answer: Force and motion
Force moves objects!
Q. Which best describes energy?
Options: An object's color · An object's smell · An object's weight · The ability to do work or make things move
Answer: The ability to do work or make things move
The source of power that makes things happen!
Q. What do you absolutely need to make a shadow?
Options: Light and an object to block it · A magnet · Water · Sound
Answer: Light and an object to block it
An object blocking light makes a shadow!
Q. When lifting a heavy rock with a lever, what if you move the pivot closer to the rock?
Options: It takes more force · It takes less force · No change · It won't lift
Answer: It takes less force
Put the pivot close to the object!
Q. Why does a sled slide so well on snow?
Options: Little friction · Because of magnets · There's no gravity · Because of wind
Answer: Little friction
Smooth snow means little friction!
Q. What does your foot pass to a soccer ball when you kick it?
Options: Light · Only sound · Kinetic energy · Color
Answer: Kinetic energy
Your foot's force becomes the ball's motion!
Q. Why does an electric car have no exhaust fumes?
Options: It's small · It runs on electricity without burning fuel · It's light · It's slow
Answer: It runs on electricity without burning fuel
It moves on battery electricity!
Q. Where does the energy that moves our body come from?
Options: Electricity · Wind · Only sunlight · Food
Answer: Food
We eat food and get our power!
Q. Why does a water wheel spin harder when you pour water from higher up?
Options: Because of wind · It has more potential energy · Because of sound · The water is lighter
Answer: It has more potential energy
The higher it is, the more force as it falls!
Q. What wheel with a rope lifts heavy things easily?
Options: A pulley · A gear · A ramp · An axle
Answer: A pulley
A pulley changes the direction of force, and several together let you lift heavy things with little effort.
Q. What bar uses a pivot to lift heavy things with little force?
Options: A pole · A pulley · A lever · A screw
Answer: A lever
A lever uses a pivot to move a heavy object with a small force.
Q. What toothed wheels mesh together to pass along force?
Options: Gears · An axle · A wedge · A lever
Answer: Gears
Gears mesh and turn together to pass along force and rotation.
Q. What is this, meshing and turning inside a clock to move time along?
Options: A screw · A wheel · Clock gears · A mainspring
Answer: Clock gears
Inside a clock, many gears mesh and turn to move the hands.
Q. What rolls to make moving heavy things easy?
Options: A wedge · A lever · A crane · A wheel
Answer: A wheel
A wheel rolls, cutting friction so heavy things move easily.
Q. What slanted thing makes it easier to push heavy things up?
Options: A bridge · A hill · A slide · An inclined plane
Answer: An inclined plane
An inclined plane (ramp) is slanted, so you can push heavy things up bit by bit.
Q. What do you twist round and round to hold something tight?
Options: An inclined plane · A screw · A crane · A wedge
Answer: A screw
A screw is an inclined plane wrapped in a spiral — twist it to tighten things.
Q. What pointy thing is driven into a gap to split or pry things apart?
Options: A knife · An axe · A nail · A wedge
Answer: A wedge
A wedge focuses force at its sharp tip to split wood or stone.
Q. What big machine lifts heavy loads to high places?
Options: A crane · A truck · A ladder · An excavator
Answer: A crane
A crane uses pulleys to lift heavy loads high up.
Q. What tool uses the lever principle to crack a hard walnut?
Options: A nutcracker · A hammer · Scissors · Tongs
Answer: A nutcracker
A nutcracker uses the lever principle to turn a small force into a big one and crack the hard shell.
Q. What tool has two blades that move like levers to cut paper?
Options: Scissors · A knife · Pliers · Tongs
Answer: Scissors
Scissors are two levers meeting, cutting things with a small force.
Q. What tool carries heavy loads on a single wheel?
Options: A carrying frame · A stroller · A wheelbarrow · A cart
Answer: A wheelbarrow
A wheelbarrow uses a wheel and the lever principle to carry heavy loads easily.
Q. What device uses a fast-spinning wheel to stay balanced without tipping?
Options: An axle · A globe · A top · A gyroscope
Answer: A gyroscope
A gyroscope's fast-spinning wheel holds its direction, so it's used for balance.
Q. What panel makes electricity from sunlight?
Options: A solar cooker · A wind turbine · A wire · A solar panel
Answer: A solar panel
A solar panel takes in sunlight and turns it into electrical energy.
Q. What place lays out solar panels across a wide area to make electricity?
Options: A solar panel · A wind turbine · A solar power plant · A substation
Answer: A solar power plant
A solar power plant gathers sunlight with countless panels to make electricity.
Q. What tool gathers sunlight in one spot to cook food?
Options: An umbrella · A brazier · A solar cooker · A solar panel
Answer: A solar cooker
A solar cooker uses mirrors to focus sunlight in one place and cook with that heat.
Q. What spins blades with wind power to make electricity?
Options: A pinwheel · A wind turbine · A windsock · A sailboat
Answer: A wind turbine
A wind turbine makes electricity from the force of wind spinning its big blades.
Q. What place has many wind turbines making electricity together?
Options: A windmill · A solar power plant · A power plant · A wind farm
Answer: A wind farm
A wind farm gathers many turbines together to make more electricity.
Q. What big wall blocks a river to make electricity from its force?
Options: A solar panel · A solar cooker · A dam · A wire
Answer: A dam
A dam holds water up high and makes electricity from the force of it falling.
Q. What machine makes electricity by burning fuel or being spun?
Options: A generator · A turbine · An engine · A transformer
Answer: A generator
A generator turns the force of spinning into electrical energy.
Q. What sucks in air and blasts it out to push an airplane forward?
Options: A jet engine · A pump · A blower · A propeller
Answer: A jet engine
A jet engine burns fuel inside and blasts hot air backward to move forward.
Q. What steel tower holds high wires to send electricity far away?
Options: A transmission tower · A utility pole · A wire · A steel tower
Answer: A transmission tower
Transmission towers carry electricity from the power plant far across the land on wires.
Q. What line on a utility pole does electricity travel through?
Options: A rope · A power line · An electric cord · A string
Answer: A power line
A power line is the path electricity flows along to reach every home.
Q. What old train ran on the force of steam from boiling water?
Options: A steam locomotive · A bus · A train · A subway
Answer: A steam locomotive
A steam locomotive burned coal to boil water, and the steam's force turned its wheels.
Q. What turns electricity into light to brighten a room?
Options: A plug · A battery · A flashlight · A light bulb
Answer: A light bulb
A light bulb turns electrical energy into light energy to brighten dark places.
Q. What modern bulb uses little electricity and lasts a long time?
Options: A candle · A fluorescent light · A lamp · An LED bulb
Answer: An LED bulb
An LED uses just a little electricity yet shines bright and lasts long.
Q. What do you carry in your hand to light up dark places?
Options: A light bulb · A lighter · A lantern · A flashlight
Answer: A flashlight
A flashlight uses battery electricity to light a bulb and shine into the dark.
Q. What do you push into an outlet to connect electricity?
Options: A charger · A wire · A cord · A plug
Answer: A plug
A plug goes into an outlet to connect electricity to an appliance.
Q. What's in the wall that you plug into to use electricity?
Options: An outlet · A wire · A charger · A cord
Answer: An outlet
An outlet connects to the wires in the wall, so plugging in lets electricity through.
Q. What do you press to turn a light on and off?
Options: A button · A handle · A knob · A switch
Answer: A switch
A switch connects and breaks the path of electricity to turn lights on and off.
Q. What spins blades with electricity to make a cool breeze?
Options: An air conditioner · A blower · A fan · A pinwheel
Answer: A fan
A fan uses an electric motor to spin blades and stir up a breeze.
Q. What car charges up with electricity instead of gas?
Options: An electric car · A bus · A charger · A truck
Answer: An electric car
An electric car charges its battery and runs on a motor.
Q. What uses electricity to blow warm air and dry your hair?
Options: A fan · A hair dryer · A heater · A flashlight
Answer: A hair dryer
A hair dryer uses electricity to make heat and wind together to dry your hair.
Q. What heater warms a room with hot water or electricity?
Options: A radiator · A boiler · A fan · An air conditioner
Answer: A radiator
A radiator gives off heat from hot water or electricity to warm a room.
Q. What burns firewood and warms a room with its heat?
Options: A brazier · A fireplace · A wood stove · A furnace
Answer: A wood stove
A wood stove warms a room with the heat energy from burning wood.
Q. What is it called when rubbing a balloon on your head makes hair stick to it?
Options: Light · Friction · Electricity · Static electricity
Answer: Static electricity
Static electricity builds up from rubbing and pulls light things toward it.
Q. What has an N pole and an S pole at its ends and pulls iron?
Options: A battery · A compass · A bar magnet · A horseshoe magnet
Answer: A bar magnet
A bar magnet pulls metal with the N and S poles at its two ends.
Q. What pattern appears when you sprinkle iron filings around a magnet?
Options: A magnet · Magnetic field lines · Iron filings · A mark
Answer: Magnetic field lines
Sprinkle iron filings around a magnet and the invisible shape of its force appears.
Q. What playground ride uses the lever principle as two people go up and down?
Options: A trampoline · Bumper cars · A seesaw · A carousel
Answer: A seesaw
A seesaw is a lever ride with a pivot in the middle and both sides going up and down.
Q. What playground ride swings back and forth?
Options: A roller coaster · A seesaw · A Ferris wheel · A swing
Answer: A swing
A swing moves like a pendulum — the higher it goes, the more potential energy it has.
Q. What playground ride do you slide down from up high?
Options: A swing · A carousel · A Ferris wheel · A slide
Answer: A slide
A slide is an inclined plane, and gravity carries you down it.
Q. What ride climbs high and races down fast?
Options: A carousel · A roller coaster · A Ferris wheel · A seesaw
Answer: A roller coaster
A roller coaster runs as the potential energy of height turns into fast kinetic energy.
Q. What ride slowly turns a giant wheel to lift you up high?
Options: A carousel · A roller coaster · A pirate ship ride · A Ferris wheel
Answer: A Ferris wheel
A Ferris wheel turns a big wheel to lift people high up, nice and slow.
Q. What ride spins you around on a wooden horse?
Options: A carousel · A rocking horse · A top · A swing
Answer: A carousel
A carousel spins around a center point in circular motion.
Q. What electric play car do you ride and bump into others?
Options: A go-kart · Bumper cars · A car · A crash car
Answer: Bumper cars
When bumper cars collide, the force transfers and pushes the other car back.
Q. What springs you back up when you jump on it?
Options: A net · A trampoline · A cushion · A spring
Answer: A trampoline
A trampoline's tight fabric and springs use elasticity to bounce you up.
Q. What ride do you slide down a rope from up high?
Options: A slide · A zip line · A rope · A cord
Answer: A zip line
A zip line is a ride where gravity carries you down a slanted cable.
Q. What board bends and springs you high into the air?
Options: A diving board · A stand · A slide · A step
Answer: A diving board
A diving board's bending and springing back launches a person high with elasticity.
Q. What stick with a spring do you bounce around on?
Options: A hopper · A stick · A pogo stick · A cane
Answer: A pogo stick
A pogo stick uses a spring's elasticity to bounce you up and down.
Q. What toy spins around when you twist it?
Options: Dominoes · A spinning top · Newton's cradle · A slinky
Answer: A spinning top
A top spins fast, balancing itself without tipping over.
Q. What toy winds and unwinds a string to go up and down?
Options: A top · A yo-yo · A ball · A weight
Answer: A yo-yo
A yo-yo gains kinetic energy going down and winds back up the string.
Q. What long stretchy toy walks itself down the stairs?
Options: A slinky · A yo-yo · A top · A rubber ball
Answer: A slinky
A slinky uses a spring's elasticity to walk itself down the stairs.
Q. What is this weight on a string that swings side to side?
Options: A pendulum · A swing · A clock · A top
Answer: A pendulum
A pendulum's weight swings side to side in a steady rhythm. A swing works the same way.
Q. What device has steel balls that collide and pass force down the line?
Options: A toy · Marbles · Newton's cradle · A clock pendulum
Answer: Newton's cradle
In Newton's cradle, one ball strikes and the force travels to the ball at the far end.
Q. What game has one piece fall and knock over a whole line?
Options: Cards · Bricks · Dominoes · Tiles
Answer: Dominoes
Dominoes fall one after another, each passing force to the next.
Q. What bounces back up when you throw it at the ground?
Options: A balloon · A ball · A rubber ball · A marble
Answer: A ball
A ball squashes and springs back on impact, bouncing up with elasticity.
Q. What coiled thing returns to shape when pressed or pulled?
Options: A screw · Wire · A spring · A rubber band
Answer: A spring
A spring stretches or squeezes with force, then returns to its original shape.
Q. What scale weighs things by how far a spring stretches?
Options: A balance scale · A thermometer · A spring scale · A ruler
Answer: A spring scale
A spring scale weighs things by how much the spring stretches — heavier means longer.
Q. What do you pull back and release to shoot an arrow far?
Options: A rubber band · A pole · A bow · A slingshot
Answer: A bow
A bow stores elastic energy as you draw it, then sends the arrow flying far.
Q. What shoots a stone by pulling back a rubber band?
Options: A slingshot · A bullet · A bow · A rubber band
Answer: A slingshot
A slingshot uses a rubber band's elasticity to send a small stone or pellet flying.
Q. What old weapon used levers and elasticity to hurl stones far?
Options: A stone · A cannon · A slingshot · A catapult
Answer: A catapult
A catapult used levers and elasticity to fling heavy stones over castle walls.
Q. What instrument makes sound as its skin vibrates when struck?
Options: A drum · A xylophone · A speaker · A flute
Answer: A drum
A drum makes sound as its tight skin vibrates.
Q. What rings out with sound when struck?
Options: A bell · A whistle · A tuning fork · A violin
Answer: A bell
A bell makes a clear ringing sound as its metal vibrates.
Q. What U-shaped tool vibrates at one steady pitch when struck?
Options: Tweezers · A rod · A bell · A tuning fork
Answer: A tuning fork
A tuning fork vibrates at one steady pitch, so it's used as a sound standard.
Q. What string instrument makes sound when you pluck it?
Options: A tuning fork · A guitar · A violin · A flute
Answer: A guitar
A guitar's strings vibrate to make sound, and its body makes it ring out louder.
Q. What string instrument makes sound by drawing a bow across the strings?
Options: A harp · A cello · A guitar · A violin
Answer: A violin
A violin makes sound as a bow rubs the strings and sets them vibrating.
Q. What instrument makes sound as strings inside ring when you press a key?
Options: A xylophone · A keyboard · A harpsichord · A piano
Answer: A piano
On a piano, pressing a key makes a hammer strike a string to make sound.
Q. What instrument makes sound when you strike bars of different lengths?
Options: A percussion instrument · A marimba · A bell · A xylophone
Answer: A xylophone
A xylophone's bars make different pitches depending on their length.
Q. What wind instrument do you blow across sideways?
Options: A flute · A recorder · An ocarina · A pipe
Answer: A flute
A flute is a wind instrument — the air inside vibrates to make the sound.
Q. What makes a shrill sound when you blow it?
Options: A bell · A chime · A whistle · A horn
Answer: A whistle
A whistle makes a loud sound as the air and a little ball inside vibrate.
Q. What turns electric signals into loud sound?
Options: An amp · A radio · A speaker · A megaphone
Answer: A speaker
A speaker uses electric signals to vibrate a thin panel and make sound.
Q. What reflects light to show us our own reflection?
Options: A flashlight · A magnifying glass · A lighthouse · A mirror
Answer: A mirror
A mirror reflects light straight back, showing us our reflection.
Q. What gathers or spreads light to make things look bigger or smaller?
Options: A lens · Glass · A prism · Quartz
Answer: A lens
A lens bends light to make objects look larger or smaller.
Q. What dark area forms behind an object that blocks light?
Options: A shadow · Shade · A reflection · A silhouette
Answer: A shadow
A shadow is the dark area behind an object where light can't pass through.
Q. What shines a light at sea to guide ships at night?
Options: A lighthouse · A utility pole · A watchtower · A tower
Answer: A lighthouse
A lighthouse shines a bright light far out so ships can find their way safely.
Q. What very strong, thin light travels straight in one direction?
Options: A laser · A flashlight · A flame · An arrow
Answer: A laser
A laser is one color of light that travels straight and far without scattering.
Q. What used wind to spin blades and grind grain or pump water?
Options: A wind turbine · A pinwheel · A sailboat · A windmill
Answer: A windmill
A windmill uses wind power to spin big blades and grind grain or pump water.
Q. What toy spins around when the wind blows?
Options: A fan · A weather vane · An electric fan · A pinwheel
Answer: A pinwheel
A pinwheel spins as the wind pushes its blades.
Q. What on a rooftop shows which way the wind is blowing?
Options: A weather vane · A compass · A flag · An anemometer
Answer: A weather vane
A weather vane's arrow turns into the wind to show its direction.
Q. What measures wind speed by how fast its cups spin?
Options: An anemometer · A compass · A cup scale · A weather vane
Answer: An anemometer
An anemometer's cups spin faster in stronger wind, showing the wind's speed.
Q. What sock at the airport shows wind direction and strength?
Options: A windsock · A kite · An anemometer · A weather vane
Answer: A windsock
A windsock puffs out toward the wind, and how flat it lies shows the wind's strength.
Q. What boat catches wind in its sails to move?
Options: A raft · A cruise ship · A boat · A sailboat
Answer: A sailboat
A sailboat catches wind in its sails and moves on that force.
Q. What do you fly high in the sky on the wind?
Options: A balloon · A kite · A glider · A bird
Answer: A kite
A kite rises high as the wind pushes it upward.
Q. What turned with flowing water to grind grain?
Options: A turbine · A water wheel · A windmill · A waterwheel
Answer: A water wheel
A water wheel grinds grain with the force of falling water turning it.
Q. What mill building ground grain using the power of water?
Options: A windmill · A hut · A water mill · A waterwheel
Answer: A water mill
A water mill was where flowing water turned a wheel to grind grain.
Q. What do you push with your feet on pedals to roll the wheels and ride?
Options: A bicycle · A cart · Roller skates · A skateboard
Answer: A bicycle
On a bicycle, the force of your pedaling passes through gears and a chain to turn the wheels.
Q. What board with wheels do you push with your foot to ride?
Options: A sled · A skateboard · Inline skates · A scooter
Answer: A skateboard
A skateboard rolls forward as your foot pushes it along.
Q. What ride do you hold by the handle and push with one foot?
Options: A sled · A scooter · A bicycle · A unicycle
Answer: A scooter
A scooter moves as one foot pushes the ground and turns the wheels.
Q. What has wheels on the bottom of the shoes?
Options: Roller skates · Inline skates · A sled · A scooter
Answer: Roller skates
Roller skates glide along as the wheels under the shoes roll.
Q. What is this pile of burning wood that gives light and heat?
Options: A campfire · A flame · A candle · A brazier
Answer: A campfire
A campfire gives off light and heat energy as the wood burns.
Q. What puffs out steam when you boil water in it?
Options: A pot · A saucepan · A teapot · A kettle
Answer: A kettle
Boil water in a kettle and it becomes water vapor, puffing out as steam.
Q. What keeps what's inside hot or cold for a long time?
Options: A tumbler · A thermos · A cup · A cooler bottle
Answer: A thermos
A thermos blocks heat from escaping, keeping the temperature for a long time.
Q. What shoots water up into the air?
Options: A well · A faucet · A fountain · A spring
Answer: A fountain
A fountain pressurizes water to shoot it up toward the sky.
Q. What calculator runs on nothing but sunlight?
Options: A phone · A digital watch · A solar calculator · A remote
Answer: A solar calculator
A solar calculator has a tiny solar cell that takes in light and makes electricity to run.
Q. What flies by spinning big blades (a rotor) overhead?
Options: A glider · A propeller · A jet · A helicopter
Answer: A helicopter
A helicopter spins the big blades on top fast, and that force lifts it into the sky.
Q. What spinning blades push a boat or plane forward?
Options: A turbine · A propeller · Rotor blades · A fan
Answer: A propeller
A propeller spins fast, pushing water or air backward to move forward.
Q. What rises into the sky when filled with hot air?
Options: A parachute · A hot-air balloon · A glider · An airship
Answer: A hot-air balloon
Heat the air inside a hot-air balloon and it gets light enough to rise.
Q. What catches air resistance to bring you down slowly?
Options: A tent · A glider · A sail · A parachute
Answer: A parachute
A parachute spreads wide to catch lots of air resistance and come down slowly and safely.
Q. What set of stairs moves by electricity to carry people up?
Options: An escalator · Stairs · A moving walkway · A conveyor belt
Answer: An escalator
An escalator's steps move with electric power to carry people up and down.
Q. What hangs from the eaves and makes a clear sound when the wind blows?
Options: A wind chime · A weather vane · A bell sound · A wind bell
Answer: A wind chime
A wind chime makes a clear sound as its pieces knock together in the wind.