A) The weight of a person is given by:

where m is the mass of the person and g is the gravitational acceleration. In this problem, the mass of the person is m=60.0 kg, while the value of g is

, therefore the weight of the person is

b) The gravitational potential energy at the top of the hill is U=1000 J. The potential energy is also given by the product between the weight W and the height of the hill h:

If we rearrange the equation, we can calculate the height of the hill, h:

c) At the bottom of the hill, all the potential energy at the top of the hill has converted into kinetic energy:

where m is the mass and v is the speed. If we rearrange the formula, we can calculate the speed at the bottom of the hill: