Abrick is dropped from the top of a building through the air (friction is present) to the ground below. part a how does the brick's kinetic energy (k) just before striking the ground compare with the gravitational potential energy ugrav at the top of the building? set y=0 at the ground level. how does the brick's kinetic energy () just before striking the ground compare with the gravitational potential energy at the top of the building? set at the ground level. k is equal to ugrav. k is greater than ugrav. k is less than ugrav.