A roller coaster car is pulled to the top of the first hill, pauses there, and then races down the track. As the car travels down the hill, what happens to its energy?

On a coaster with no motor after the lift hill, the second hill is always shorter than the first. Why can the car never climb back to its starting height?

Two coaster cars sit at the top of the same hill. The heavier car stores the same amount of gravitational potential energy as the lighter car.

A student connects a battery to a small light bulb with two wires. The bulb glows and its base feels warm. Trace where the battery's stored energy went.

In a circuit, a battery runs a small motor that winds up a string and slowly lifts a metal washer off the desk. Which energy change does the lifted washer show?

A battery, wires, and a buzzer form a closed circuit. The buzzer sounds and the wires feel slightly warm. What happened to the chemical potential energy the battery supplied?

A student opens the switch in a battery-and-bulb circuit and the bulb goes dark. What happened to the chemical potential energy still inside the battery?

A lit light bulb glows steadily as long as the circuit stays closed, but goes dark within a second if the battery is removed. Why must the battery keep supplying energy?

A green leaf sits in bright sunlight and the plant builds sugar inside its cells. Which energy change does photosynthesis carry out?

In a food web, grass grows in a sunny field, a grasshopper eats the grass, and a bird eats the grasshopper. Where did the chemical potential energy in the bird's body first come from?

Only a small part of the energy stored in one organism ends up stored in the animal that eats it. What happens to the rest of that energy?

A fallen tree on the forest floor is slowly broken down by fungi and bacteria. What happens to the chemical potential energy that was stored in the wood?

Energy moves through a food web from producers to consumers to decomposers, and along the way it changes form without any of it being created or destroyed.

A student stretches a rubber band around two fingers and lets go, launching a foam ball across the classroom. Trace the energy in this launch.

A ball dropped onto a hard floor bounces a little lower each time, and after several bounces it stops. Where did the energy the ball started with go?

A child on a playground swing pumps their legs on every pass, and after several passes they rise higher than before. Trace where the extra energy stored at the top of the arc came from.

A drop-tower ride carries riders straight up, holds them at the top for a few seconds, then releases them. Which form of energy is stored while the riders wait at the top?

Bumper cars at a fair pick up electricity from the ride floor and ceiling. A car speeds across the floor, its motor hums, and its housing warms up. Trace where that energy went.

An electric motor drives the chain that hauls a coaster car up the first hill. What does the motor mainly do with the energy the circuit delivers to it?

A student eats a carrot at lunch and later runs a race in gym class. Trace the energy from the Sun to the student's moving legs.