Sand is falling into a conical pile at the rate of 10 m^3/s such that height of the pile is always half the diameter of the base of the pile find the rate at which the height of the pile is changing when the pile is 5 m. high.

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.