While at the beach, you see someone standing in the water about to be wrecked by a wave. The low part of the swell is at their knees and the top of the incoming wave is 6 feet higher, above their head. What is the amplitude of the wave.

Ahot-air balloon is 11.0 m above the ground and rising at a speed of 7.00 m/s. a ball is thrown horizontally from the balloon basket at a speed of 9.00 m/s. ignore friction and air resistance and find the speed of the ball when it strikes the ground.