Starter quiz

  • Which of the following energy stores does friction transfer energy into?
    • chemical store
    • gravitational store
    • kinetic store
    • thermal store  ✓
  • Why does a hot cup of tea cool down?
    • All of its energy is used up.
    • All of its energy is transferred to the surroundings.
    • Some of its energy is used up.
    • Some of its energy is transferred to the surroundings.  ✓
  • Why is the rebound height of a ball not the same as the height that it was dropped from?
    • Earth's gravitational force is pulling the ball downwards.
    • The normal reaction force from the ground is less than the gravitational force.
    • Pushing air out of the way uses up some of the ball's energy.
    • Pushing air out of the way transfers some energy to the air particles.  ✓
  • The law of conservation of energy states that energy cannot be created or ...
    • 'destroyed' ✓
  • Match the values on the left to the equivalent values on the right.
    • 1.5 kW
      ⇔
      1500 W ✓
    • 3400 J
      ⇔
      3.4 kJ ✓
    • 0.34 kJ
      ⇔
      340 J ✓
    • 15 W
      ⇔
      0.015 kW ✓
  • Which of the following statements explains why an electric heater can be considered to be 100% efficient?
    • An electric heater transfers no energy to the surroundings.
    • An electric heater transfers all energy usefully into thermal stores.  ✓
    • An electric heater has a low power input.
    • An electric heater has a high power output.
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