Problem 3.58 A hot-air balloon of diameter 12 m rises vertically at a constant speed of 14 m/s .

Problem 3.58

A hot-air balloon of diameter 12 m

 rises vertically at a constant speed of 14 m/s

 . A passenger accidentally drops his camera from the railing of the basket when it is 15 m

above the ground.

If the balloon continues to rise at the same speed, how high is the railing when the camera hits the ground?

Express your answer with the appropriate units.