Question

A diver leaves the platform with her body straight. Her body is in a relatively slow rotation, with an angular speed of 4.0 rad/s. She then tucks into a pike position, with her body essentially folded in half. When straight her moment of inertia is 13.5 kg·m2, and when in the pike position it is 3.4 kg·m2. The next two questions have to do with this diver. Calculate her angular momentum when straight. a. 6 kg·m2/s b. 39 kg·m2/s c. 54 kg·m2/s d. 78 kg·m2/s

Using the conservation of angular momentum, determine her angular speed when in the pike position. a. 100 rad/s b. 75 rad/s c. 37 rad/s d. 16 rad/s

Answer 1

In straight position :- لیا 1) angular velocity : . 4.0 radis S 2 moment Il of inertia : 13.5 kg m In pike position :- moment of inertia : Iz 3-4 kg. m² angular velocity درا (let) (i) Angular mamentum L = I w 1, w L= (13.5 x 4.07 kg.m? S La 54 kg m? > option (c) sere (ii) using conservation moment - of angular I w. こ Iz w2 13.5 I wi x 4.0 W2 rad's I 2 3.4 W2 15.88 radis W₂ ~ 16 rad/s. → option Ca)