Turning one energy into another

Science · Energy · ages 9-10

Name ______________________ Date ____________

A stretched spring in a toy has stored elastic potential energy. True or false: that energy completely disappears the moment the spring is released.
Circle one: True False
In a rubber-band car, energy stored in the stretched band changes into motion energy when it is let go.
Circle one: True False
You built a simple heat exchanger device, but when you test it, the oil warms up much more slowly than you expected. True or false: this means you should refine your design.
Circle one: True False
You are designing a marble run with a high starting ramp. What energy conversion should you plan for as the marble rolls down?
- Gravitational potential energy into kinetic energy
- Kinetic energy into gravitational potential energy
- Elastic potential energy into sound energy
- Chemical energy into light energy
A student builds a fan powered by a battery. Which energy change happens when the fan turns on?
- Electrical energy changes into kinetic energy
- Light energy changes into sound energy
- Kinetic energy changes into electrical energy
A solar oven heats up too slowly during a test. What should the builder do next?
- Look at the test results and change the design to fix the problem
- Stop the project and start a different one
- Ignore the slow heating and call the project finished
A heat exchanger device moves thermal energy from hot air into cooler oil, warming the oil up. What happens to the energy that leaves the hot air?
- It disappears
- It stays in the hot air forever
- It transfers into the oil as thermal energy
- It turns into light
A hand-crank flashlight changes hand motion into electrical energy, then electrical energy into light. How many energy changes happen in total?
Answer: ______________
A classmate says the first design of a device is always the best one, so there is no need to test it. Do you agree?
- No, because devices never need to be tested at all
- Yes, testing just wastes time once a design is finished
- No, testing often reveals problems that make the design better
Priya's buzzer makes a loud sound during testing but also feels hot and drains the battery fast. What is the best explanation?
- The buzzer converts all its energy into sound with none wasted
- Some of the electrical energy is also changing into heat, not just sound
- The buzzer is not converting any energy at all

Answer key

For grown-ups. Fold this page away before handing over the rest.

Turning one energy into another W1-mt_K1-HopEJAB-s1

False · Energy never just disappears. It changes into another form, like motion.
True · The stretched band holds energy, and releasing it turns that stored energy into the motion of the car.
True · Testing tells you what is not working yet, so you know what to improve.
Gravitational potential energy into kinetic energy · The raised marble stores gravitational potential energy, which turns into kinetic energy as it rolls down.
Electrical energy changes into kinetic energy · The battery's electrical energy changes into the kinetic energy of the spinning fan blades.
Look at the test results and change the design to fix the problem · Testing shows what is not working yet. A good engineer uses that information to improve the design.
It transfers into the oil as thermal energy · Energy moves from the hotter thing to the cooler thing, it does not vanish.
2 · Count the changes between the energy forms: motion to electrical is one change, and electrical to light is a second change.
No, testing often reveals problems that make the design better · Testing shows what works and what does not. Engineers use test results to improve their first design.
Some of the electrical energy is also changing into heat, not just sound · Devices rarely convert energy into only the form you want. Here, some electrical energy becomes heat instead of sound.