What is the gravitational potential energy of a 4 kg bowling ball 1 m above the ground?

What is the stall speed at sea level of an airplane that weights 10000 lbs., has a wing area of 300ft^2, and a maximum lift coefficient of 1.4? what is the stall speed if flaps that double cl,max are applied?

Aball is thrown horizontally from a cliff at 8m/s .in what direction is the ball moving 2s later?

What would be the radius of the earth if it had its actual mass but had the density of nuclei? express your answer to two significant figures and include the appropriate units.