A metal ball of radius 20 cm is charged to potential 150 V. A point charge 5 nC is moved from infinity to a point near the ball surface. In doing so, work 300 nJ is performed. Find the distance from the final position of the charge to the ball surface. The answer should be expressed in centimeters |cm. The ball is in a vacuum.

A metal ball of radius 20 cm is charged to potential 150 V. A point charge 5 nC is moved from infinity to a point near the ball surface. In doing so, work 300 nJ is performed. Find the distance from the final position of the charge to the ball surface. The answer should be expressed in centimeters |cm. The ball is in a vacuum.