(a) A small piece of wet cement thrown on a well is glued to the wall. What happens to its initial energy ?

Explanation

To solve the question about what happens to the initial energy of a small piece of wet cement thrown against a wall, we can break down the process step by step.

### Step-by-Step Solution:

1. **Identify the Initial Energy**:
- When the wet cement is thrown, it possesses kinetic energy due to its motion. The initial energy can be expressed as:
\[
\text{Initial Energy} = \text{Kinetic Energy} = \frac{1}{2}mv^2
...