Gravitational potential energy is defined as the amount of energy an object possesses at a given height above the Earth's surface. The equation for gravitational energy is E = mgh. Here, m is the mass of the object, g is the acceleration due to gravity, and h is the height above the Earth's surface. Hence, the answer is E = 2000kg x 9.81m/s^2 x 2m = 39240 Joules.