Q: Answer the following question given this paragraph: Find the microwave in the Figure above . A microwave is an electromagnetic wave with a relatively long wavelength and low frequency. Microwaves are often classified as radio waves, but they have higher frequencies than other radio waves. With higher frequencies, they also have more energy. That's why microwaves are useful for heating food in microwave ovens. Microwaves have other important uses as well, including cell phone transmissions and radar. These uses are described below. You can learn more about microwaves and their uses in the video at this URL: http://www. youtube. com/watch?v=YgQQb1BVnu8 . Q: Why do microwaves have a higher energy than radio waves? A:

OPTIONS:
- higher resonance
- lower frequency
- higher decibel
- higher frequency

A: higher frequency

Q: Answer the following question given this paragraph: Air in the troposphere is warmer closer to Earth's surface. Warm air is less dense than cool air, so it rises higher in the troposphere. This starts a convection cell. Convection mixes the air in the troposphere. Rising air is also a main cause of weather. All of Earth's weather takes place in the troposphere. Q: Why does warm air rise higher in the troposphere? A:

OPTIONS:
- it is more dense than cool air
- It contains hydrogen
- it is less flourishing than cool air
- it is less dense than cool air

A: it is less dense than cool air

Q: Answer the following question given this paragraph: rates The rates at which reactants are consumed and products are formed during chemical reactions vary greatly. We can identify five factors that affect the rates of chemical reactions: the chemical nature of the reacting substances, the state of subdivision (one large lump versus many small particles) of the reactants, the temperature of the reactants, the concentration of the reactants, and the presence of a catalyst. Q: The presence of what, which acts as a trigger, affects the rate of chemical reaction? A:

OPTIONS:
- friction
- heat
- light
- catalyst

A: catalyst

Q: Answer the following question given this paragraph: 7.4 Conservative Forces and Potential Energy 9. What is a conservative force? 10. The force exerted by a diving board is conservative, provided the internal friction is negligible. Assuming friction is negligible, describe changes in the potential energy of a diving board as a swimmer dives from it, starting just before the swimmer steps on the board until just after his feet leave it. Define mechanical energy. What is the relationship of mechanical energy to nonconservative forces? What happens to mechanical energy if only conservative forces act? 12. What is the relationship of potential energy to conservative force?. Q: The force exerted by a diving board is conservative, provided the internal friction is this? A:

OPTIONS:
- static
- intrinsic
- significant
- negligible

A:
negligible