A ball is launched directly upwards from the ground. At max height, the ball has a gravitational potential energy of 10 J. If the ball the ball has a mass of 1 kg, then what was the initial velocity of the ball? Report your answer in units of meters per second (m/s) but only write down the number part.

A ball is launched directly upwards from the ground. At max height, the ball has a gravitational potential energy of 10 J. If the ball the ball has a mass of 1 kg, then what was the initial velocity of the ball? Report your answer in units of meters per second (m/s) but only write down the number part.