Flashcards in Topic 3 - Conservation of Energy Deck (55)
1 What is the unit for measuring energy?
2 What is the name for energy stored in a hot object?
3 How is energy transferred from hot objects to their surroundings?
4 Energy stored in petrol in a car is transferred to energy stored in the moving car. What are the names for these two energy stores?
5 If 100J of energy is transferred into a machine, how much is transferred out?
6 In what way is most wasted energy transferred?
7 When an object is moved to a higher position, what name is given to the energy that it then stores?
gravitational potential energy
8 What are the energy transfers when a ball bounces?
kinetic, strain/elastic potential, kinetic
9 What are the energy transfers when a moving car slows down?
kinetic ? thermal energy stored in the brakes/surroundings, energy transferred by forces
10 Name three different types of object or substance that store energy in chemicals.
food, fuel, batteries/cells
11 Name two ways in which a television transfers useful energy to its surroundings.
12 Name one way in which a television transfers wasted energy to its surroundings.
13 In what way do most machines or processes transfer wasted energy to the surroundings?
14 Name two machines in which energy transferred by heating is useful energy.
any two sensible answers, such as cooker or fire
15 When a kettle boils water, the useful energy ends up stored as thermal energy in the hot water. Where does the wasted energy end up?
thermal energy in kettle/surroundings
16 When a moving car brakes and comes to a stop, where does all the kinetic energy it was storing eventually end up?
thermal energy in the surroundings
17 When a moving car hits a wall, what happens to the kinetic energy it was originally storing?
kinetic energy of crash fragments, transferred to surroundings by sound but all ends up as thermal energy in the surroundings
18 What does dissipated mean?
19 Which wastes more energy: a more efficient machine or a less efficient machine?
20 What happens to the particles in a solid when the solid gets warmer?
21 One end of a metal bar is heated. What is the name for the way energy is transferred along the bar?
22 What kind of materials are good thermal conductors?
23 Name two materials that are good thermal insulators.
any two from wood, plastic, wool, etc.
24 What is the name for the way in which energy is transferred in a fluid
25 What causes a convection current?
part of the fluid being hotter than the rest/warm fluid rises
26 Materials that contain trapped air are good insulators. Why does the air need to be trapped?
so it cannot transfer energy by convection
27 How does warmth from the Sun reach the Earth?
28 Will a black car or a white car get hotter on a sunny day?
29 Name one thing a homeowner can do to reduce the money they spend on heating.
any from insulate loft, fit double glazing etc.