You are given the mass of an object which is 3.00 kilograms. Also, you are given the energy exerted by the object at 300 Joules. You are required to find the height or distance travelled by your object. You need to know that potential energy is equal to the mass times the gravitational force times the height of the object. Let us denote P as our energy, m as the mass of the object, g as the gravitational force and h as the height. So,
P = mgh
h = P/mg
h = (300 J)/(3kg)(9.8066 m/s2)
h = 10.2 m