Joe has a weight of 731 N (about 161 lb) when he is standing on the surface of the earth. What would his weight (the gravitational force due to the earth) be if he doubled his distance from the center of the earth?

Why is rain likely when warm, moisture-laden air meets cold air? a) the lighter warm air will rise and cool down, causing condensation and rain. b) the cold air moves faster and pushes the warm air away, causing condensation and rain. c) the moisture in the warm air condenses on contact with the cold air, causing rain to fall. d) the cold air mixes with the warm air, reducing its temperature causing moisture to condense.