The Cannonball

This photo represents many physics concepts that we studied. The first concept represented is Hooke’s law of elasticity. When the subject of the photo jumps onto the spring-based diving board, the board contracts with a displacement proportional to the force with which it launched the subject. The formula, is represented by F = -kx, where k is a constant known commonly as the spring constant. The springs of the board then return to their original shapes and in the process launch the subject into projectile motion. Because the subject was launched into the air, we know that the force of the springs that was translated into the motion of the subject was greater than the weight of the subject. We also need to involve the torque of the diving board, since the axis of motion of the board during the springs’ contractions was not centered below the subject.

             The subject of the photo undergoes projectile motion while jumping into the pool. We know this if we look at the photo. These series of photos were taken at a constant shutter speed, meaning that the time between each shot of the subject is approximately equal. By looking at the photo, we can tell that the horizontal distance covered by the subject between each photo is approximately equal. We can then determine that the horizontal velocity is approximately constant, which is in keeping with the kinematic equation:  x = v_xt. Meanwhile, the parabolic trajectory of the subject suggests the vertical component of motion undergoes a constant acceleration. That acceleration is more commonly known as gravity.