The physics that is in this picture of a girl playing tennis is Newton's Second Law of Motion. This law states that "the acceleration of an object is directly proportional to the net force on the object and indirectly proportional to the mass of the object" (Dowell 11). When the tennis racket hits the ball, this law is true. In the picture, the girl is about to hit the ball, and once the ball is hit, Newton's Second Law of Motion is visible because the hit will combine with the other forced on the ball to create a net force causing acceleration.
Newton's Second Law