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Conservation of energy and wasted energy

8th grade (Year 9 in England) · 16 questions · Common Core: NGSS.MS-PS3-5, NGSS.HS-PS3-1 · England: KS3 Physics: Energy (changes in systems), KS4 Combined Science: Energy

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Date

Score/ 16

  1. Question 1

    A kettle is supplied with 200 J of energy. It transfers 20 J usefully. How much energy is wasted, in J?

    AnswerJ

  2. Question 2

    Where does most wasted energy usually end up?

    • A. destroyed
    • B. heating the surroundings
    • C. back in the battery
    • D. inside the plug

  3. Question 3

    Conservation of energy: which statement is NOT true?

    • A. A Sankey diagram shows useful and wasted energy.
    • B. No real machine is 100% efficient.
    • C. Wasted energy is destroyed.
    • D. The total energy in a closed system stays the same.

  4. Question 4

    A motor is supplied with 1200 J of energy. It transfers 900 J usefully. How much energy is wasted, in J?

    AnswerJ

  5. Question 5

    Where does most wasted energy usually end up?

    • A. destroyed
    • B. heating the surroundings
    • C. back in the battery
    • D. inside the plug

  6. Question 6

    Conservation of energy: which statement is NOT true?

    • A. A Sankey diagram shows useful and wasted energy.
    • B. The total energy in a closed system stays the same.
    • C. Wasted energy is often transferred to the surroundings by heating.
    • D. Energy is used up and disappears.

  7. Question 7

    A kettle is supplied with 1200 J of energy. It transfers 240 J usefully. How much energy is wasted, in J?

    AnswerJ

  8. Question 8

    A ball is dropped and each bounce is lower. Where did the energy go?

    • A. It went into the ball's mass
    • B. It was transferred to the surroundings as heat and sound
    • C. It was destroyed
    • D. Gravity took it

  9. Question 9

    Conservation of energy: which statement is NOT true?

    • A. Wasted energy is destroyed.
    • B. No real machine is 100% efficient.
    • C. A Sankey diagram shows useful and wasted energy.
    • D. The total energy in a closed system stays the same.

  10. Question 10

    A kettle is supplied with 500 J of energy. It transfers 300 J usefully. How much energy is wasted, in J?

    AnswerJ

  11. Question 11

    How can wasted energy in a machine with moving parts be reduced?

    • A. make it move faster
    • B. lubricate the parts to reduce friction
    • C. paint it a darker colour
    • D. remove the oil

  12. Question 12

    Conservation of energy: which statement is NOT true?

    • A. Wasted energy is often transferred to the surroundings by heating.
    • B. A machine can give out more energy than it takes in.
    • C. The total energy in a closed system stays the same.
    • D. No real machine is 100% efficient.

  13. Question 13

    A speaker is supplied with 500 J of energy. It transfers 200 J usefully. How much energy is wasted, in J?

    AnswerJ

  14. Question 14

    How can wasted energy in a machine with moving parts be reduced?

    • A. lubricate the parts to reduce friction
    • B. remove the oil
    • C. paint it a darker colour
    • D. make it move faster

  15. Question 15

    Conservation of energy: which statement is NOT true?

    • A. Wasted energy is destroyed.
    • B. Wasted energy is often transferred to the surroundings by heating.
    • C. A Sankey diagram shows useful and wasted energy.
    • D. The total energy in a closed system stays the same.

  16. Question 16

    A speaker is supplied with 1200 J of energy. It transfers 900 J usefully. How much energy is wasted, in J?

    AnswerJ

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  1. 180 J
  2. heating the surroundings
  3. Wasted energy is destroyed.
  4. 300 J
  5. heating the surroundings
  6. Energy is used up and disappears.
  7. 960 J
  8. It was transferred to the surroundings as heat and sound
  9. Wasted energy is destroyed.
  10. 200 J
  11. lubricate the parts to reduce friction
  12. A machine can give out more energy than it takes in.
  13. 300 J
  14. lubricate the parts to reduce friction
  15. Wasted energy is destroyed.
  16. 300 J