Using the principle of the conservation of energy, calculate the maximum speed of a ball of 5.0kg that has been dropped from a height of 20m. (Given that the gravitational field strength is equal to 9.8N/kg)

Answer: 20ms^-1The gravitational potential energy before the ball is dropped is equal to mgh. This gives the ball a maximum gravitational potential energy of 5.0kg * 9.8N/kg 20m which is equal to 980 J. At the maximum ball speed, the kinetic energy of the ball will be equal to 980J- this will be the point at which the ball is at an altitude of zero. As kinetic energy is given as 1/2 mv², the velocity can be found by dividing the 980 J by one half (multiplying by two) and dividing by the mass (5kg) and then taking the square root of the resulting number. This velocity, v, will be equal to √9802/5 . This is equal to 20 ms^-1