Energy Wastage
Physics: Cambridge International GCSE Supplement, topic 1.11.13
Wasted Energy
When one type of energy is converted into another type of energy, some energy is wasted (transferred into unwanted types of energy). This dissipates (is spread out) to anything nearby.
Car engines - noise and heat
- Car engines make a lot of noise and get hot when they are being used to move you about.
- The useful energy here is kinetic energy because you want the car to move you from one place to another.
- The heat and sound energy are wasted energy because they are of no use to you.
Wires - heat
- When wires are used in an electrical circuit they heat up.
- This is often not useful energy so is wasted.
Friction - heat
- In almost every energy transfer, friction creates heat energy and this energy is often wasted.
Test yourself on Energy Wastage
Which of these is an example of useful energy?
Which of these statements about wasted energy are true?
Perpetual machines can continue moving forever without ever stopping. Why are perpetual motion machines impossible?