Topic 3 Conservation of Energy Flashcards
1 What is the unit for measuring energy?
joule
2 What is the name for energy stored in a hot object?
thermal/internal
3 How is energy transferred from hot objects to their surroundings?
by heating/convection/conduction/radiation/evaporation
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?
chemical, kinetic
5 If 100J of energy is transferred into a machine, how much is transferred out?
100J
6 In what way is most wasted energy transferred?
by heating
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.
light, sound
12 Name one way in which a television transfers wasted energy to its surroundings.
by heating
13 In what way do most machines or processes transfer wasted energy to the surroundings?
by heating
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?
spread out
19 Which wastes more energy: a more efficient machine or a less efficient machine?
less efficient
20 What happens to the particles in a solid when the solid gets warmer?
vibrate more
21 One end of a metal bar is heated. What is the name for the way energy is transferred along the bar?
conduction
22 What kind of materials are good thermal conductors?
metals
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
Convection
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?
radiation
28 Will a black car or a white car get hotter on a sunny day?
black
29 Name one thing a homeowner can do to reduce the money they spend on heating.
any from insulate loft, fit double glazing etc.
30 What is the unit for measuring energy?
joule
31 What is the name for energy stored in an object because it is in a high position?
gravitational potential energy
32 What is the name for energy stored in a moving object?
kinetic energy
33 How many grams are there in a kilogram?
1000
34 What is the law of conservation of energy?
total energy stays the same, or energy cannot be created or destroyed .
35 A ball has 5J of gravitational potential energy before it is dropped. How much kinetic energy is it storing the moment before it hits the floor ? 0J, less than 5J, 5J, more than 5J?
5J
36 How can you increase the gravitational potential energy stored in a box?
move it up, away from the Earth
37 Name a store of chemical energy.
any from coal, oil, natural gas, food, batteries/cells
38 What do we call the kind of energy stored inside atoms?
nuclear energy or atomic energy
39 When we burn a fuel, how is the energy transferred to the surroundings?
by heating
40 How is energy transferred to machines such as TVs and computers?
by electricity
41 Is electricity a fuel?
no
42 Name two fuels that are used by most vehicles on the roads.
petrol, diesel
43 Name two fuels that we call fossil fuels.
any two from coal, oil, natural gas, or oil derivatives such as petrol and diesel
44 What are the two products of the complete burning of fossil fuels?
carbon dioxide, water
45 What effect does carbon dioxide in the atmosphere have on the temperature of the Earth?
keeps it warm
46 What is the name for the idea that the Earth is getting warmer?
climate change/global warming
47 Name four different non-renewable resources.
coal, oil, natural gas, nuclear fuel/uranium
48 Name two different uses for natural gas.
power stations, heating homes, cooking
49 Name the main use for coal.
power stations
50 How is uranium used?
nuclear power stations
51 What gas do fossil-fuel power stations emit that nuclear power stations do not?
carbon dioxide
52 Why is adding carbon dioxide to the atmosphere a problem?
contributing to climate change
53 Why will supplies of fossil fuels eventually run out?
we are using them faster than they can be replaced
54 Name two forms of renewable energy.
two from: solar, wind, waves, tides, bio-fuel
55 What is the name for a fuel made from plants or from animal wastes?
bio-fuel