If you are standing on the Moon and release a strong balloon filled with helium gas, the balloon will
1) rise.
2) fall.
3) neither rise nor fall.
This occurs because
4) helium gas is lighter than air.
5) the Moon does not have an atmosphere.
6) gravity is weaker on the Moon.
Answer: 2, 5
You might also like to view...
Now study Figure 10.39, which shows global temperatures from 1880. Focus on the period since about 1960, and compare what you notice about the temperatures to what you've learned about carbon dioxide levels in Questions 1—4. Which of the following statements best describes the relationship?
A) The warmest years correlate exactly with the years of greatest CO2 abundance, indicating that CO2 is the single most important factor controlling global temperature changes. B) The warmest years correlate roughly with the years of greatest CO2 abundance, indicating that CO2 is important but other factors also contribute to global temperature changes. C) The warmest years are not correlated with years of high CO2 abundance, indicating that factors other than CO2 have the most important effect on global temperature changes.
What happens to the half-life of a radioactive substance as we increase its temperature?
A) It does not change. B) It increases. C) It decreases at a constant rate. D) It decreases at an exponential rate.
In hot-work, a metal is deformed at temperatures that are either above the ___________temperature, or above 50 % of the absolute melting temperature.
Fill in the blank(s) with the appropriate word(s).
A box is dropped onto a conveyor belt moving at 2 m/s. If the coefficient of friction between the box and the belt is 0.3, how long before the box moves without slipping?