An object of mass 50kg is released from a height of 2m.Find the kinetic energy just before it strikes the ground

Answer Details

When an object is lifted to a height h, it gains potential energy given by: P.E = mgh, where m is the mass of the object, g is the acceleration due to gravity and h is the height. When the object is released, it starts to fall and its potential energy is converted into kinetic energy, which is given by: K.E = (1/2)mv^2, where v is the velocity of the object just before it strikes the ground. At the highest point, the potential energy is maximum and the kinetic energy is minimum. At the instant just before the object strikes the ground, the potential energy is zero and the kinetic energy is maximum. Therefore, the potential energy at the highest point is: P.E = mgh = 50 x 9.81 x 2 = 981 J Since the potential energy is converted to kinetic energy just before the object strikes the ground, the kinetic energy at that point is equal to the potential energy at the highest point: K.E = 981 J. Therefore, the correct option is: 1000J.