Question: Answer the following question given this paragraph: Look at the skateboarders in Figure below . When they push against each other, it causes them to move apart. The harder they push together, the farther apart they move. This is an example of Newton's third law of motion. Q: When two skateboarders push against each other what happens? A:
OPTIONS:
- they stick together
- they rise
- they magnetize
- they move apart
Answer: they move apart

Question: Answer the following question given this paragraph: Moving water has energy ( Figure above ). That energy is used to make electricity. Hydroelectric power harnesses the energy of water moving down a stream. Hydropower is the most widely used form of renewable energy in the world. This abundant energy source provides almost one fifth of the world's electricity. The energy of waves and tides can also be used to produce water power. At this time, wave and tidal power are rare. Q: Hydroelectric power harnesses the energy of what? A:
OPTIONS:
- weather
- heat
- air
- water
Answer: water

Question: Answer the following question given this paragraph: To prepare coal for use, the coal is first crushed into powder and burned in a furnace. Like other fuels, coal releases most of its energy as heat when it burns. The heat from the burning coal is used to boil water. This makes steam. The steam spins turbines, which creates electricity. Q: When does coal release most of its energy? A:
OPTIONS:
- when forming
- when compressed
- when falling
- when burning
Answer:
when burning