A bullet travelling with a velocity of 16 m/s penetrates a tree trunk and comes to rest in 0.4 m. Find the time taken during the retardation.

Explanation

To solve the problem step by step, we will use kinematic equations.

### Step 1: Identify the given values
- Initial velocity (u) = 16 m/s (the bullet's speed when it hits the tree)
- Final velocity (v) = 0 m/s (the bullet comes to rest)
- Displacement (s) = 0.4 m (the distance the bullet penetrates into the tree)

### Step 2: Use the first kinematic equation
...