If the radius of the earth contracts to half of its present value without change in its mass, what will be the new duration of the day?

Explanation

To solve the problem of determining the new duration of the day if the radius of the Earth contracts to half of its present value without a change in its mass, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Concept of Angular Momentum**:
The angular momentum (L) of a rotating body is given by the formula:
\[
L = I \omega
...