Verified answer

1. Force is defined as the product of a body's mass and its acceleration. Acceleration is defined as a change in velocity. Since the velocity does not change, the resultant force is 0.

2. Gravitational acceleration increases as you approach sea level. The gold would weigh the most in Death Valley and the least in Denver; buy by weight in Denver. If it were sold by mass, it does not matter where it is purchased, as the mass of the sample is the same universally.

1) Who knows--do they give you a drag coefficient? The net force is zero, of course, for a constant velocity.

2) If you assume that the gravity of the earth acts as if it were a point source (which is not really correct, but we'll go with the assumption for this problem), then

F = G mgold Mearth / r^2

So the force is greater when r is smaller (death valley). Better to buy in denver and sell in death valley. If it is sold by mass, then it doesn't matter.