A wooden ball 7 inches in radius sinks to a depth of 10 inches in a river. Find the exposed area of the ball above the water.

Answer 1

just look up the formula for the volume of a spherical cap of radius r and height h. Then plug in your numbers.

Hint: find the volume of the smaller cap and subtract it from the whole ball.

See here:

http://en.wikipedia.org/wiki/Spherical_cap

Answer 2

45 pi