A body of mass 2 kg makes an elastic collision with a second body at rest and continues to move in the original direction but with one fourth of its original speed. What is the mass (inkg) of the second body?

Explanation

To solve the problem, we will use the principles of conservation of momentum and the properties of elastic collisions.

### Step-by-Step Solution:

1. **Identify the Given Information:**
- Mass of the first body, \( m_1 = 2 \, \text{kg} \)
- Initial velocity of the first body, \( u_1 = u \) (unknown)
- Final velocity of the first body after collision, \( v_1 = \frac{u}{4} \)
...