Question

This is from my Basic Biomechanics textbook:

1. The principle explaining the creation of lift rather in air or water relies on the relationship between velocity and pressure. Which condition produces lift toward the top of the body or object?

2. Considering that angular momentum equals the amount of inertia multiplied by angular velocity and applying the Law of Conservation of Angular momentum, decreasing the radius of rotation and keeping all other factors equal will result in what?

Answer 1

1) Pressure is responsible to produce lift towards the top of the body or objects. As for example in hydrolic lift the pressure created in the bottom of the lift helps the lift to move upwards.

2) According to the law of conservation of angular momentum ,the momentum will be conserved until no external torque is applied. So when the radius of rotation decreases the moment of inertia of the body decreases hence to maintain constant angular momentum , angular speed increases.