Three children are playing in a pool in the back yard. One child is at the far left end of the pool and is splashing. A second child is laying on a float in the middle of the pool. The third child is at the far right of the pool and begins splashing as well. The child on the float in the middle of the pool notices that when both of her friends are splashing on opposite sides of the pool, she is raised much higher on her float as the waves lift her up. What phenomenon is the child in the middle of the pool experiencing?.