Biomechanics Practice Exam - Practice Test & Study Guide for Success

When a diver changes position during a dive, the principle of conservation of angular momentum is key to understanding what happens. Angular momentum is defined as the product of the moment of inertia and angular velocity. When a diver tucks or extends her body, she is altering her moment of inertia while making adjustments to her angular velocity.

According to the conservation of angular momentum, if there are no external torques acting on the system, the total angular momentum remains constant. Therefore, even as the diver changes her position, which affects her moment of inertia, her angular momentum will remain the same overall.

If the diver tucks into a ball (decreasing her moment of inertia), her angular velocity increases to keep the angular momentum constant. Conversely, if she unrolls or extends her body (increasing her moment of inertia), her angular velocity will decrease.

Thus, regardless of the specific changes in position or orientation, the total angular momentum of the diver will remain the same throughout the dive, assuming no external forces are acting on her.