I’m sitting in a boat in a pool. In the boat with me is a cannonball. What happens to the level of the pool if I take the cannonball out of the boat and drop it into the pool? Does the level increase, decrease or stay the same?

Obviously a cannon ball is more dense than water, so the level will decrease. (See friedlinguini's solution)

If we used a ball that was the same density as water, the level would not change.

If we used a balloon, the water level would increase. (if we got someone else to push it down, because otherwise it would float.)

If we had a ball that was only slightly less dense than water and it was just floating, the level would also remein unchanged, as the weight of the ball would diplace the same amount of water when floating as it would in the boat. (in order to balance the buyancy force and the weight of the ball)

Posted by Helen on 2003-03-21 05:00:03