Battery Fan Energy Chain

In the picture

1. 1Battery: stores chemical energy and supplies electrical energy.
2. 2Switch: completes or breaks the circuit so current can flow or stop.
3. 3Motor: changes electrical energy into rotational motion and releases some heat.
4. 4Fan blades: change rotational motion into moving air, the useful work.
5. 5Heat waves: show energy lost to the surroundings as warmth.

Examples

• An electric kettle changes electrical energy into heat in the water, and some heat warms the room.
• A smartphone uses battery energy for light, sound, and computing, and its case becomes warm.

Quiz: Battery Fan Energy Chain (Age 14)

1. 1

   What happens to some of the energy at each step of the fan’s energy chain?

   • It is changed into heat instead of useful work.
   • It is destroyed and disappears completely.
   • It is stored forever in the battery.
2. 2

   Compared with the total energy put in, what is true about the useful output of the fan?

   • It is always smaller because some energy is lost as heat.
   • It is always larger because the motor adds energy.
   • It is exactly equal because no energy is lost.
3. 3

   What energy change does the motor make in this chain?

   • Chemical energy into electrical energy, releasing some heat.
   • Rotational motion into moving air, releasing some heat.
   • Electrical energy into rotational motion, releasing some heat.

The answers, each with its explanation, are in the app. This lesson has left the free week, so its quiz is part of the subscription.