A 1.2 kilogram basketball travelling at 7.5 metres per second hits the back of a 12 kilogram wagon and bounces off a 3.8 meters per second, sending the wagon off in the original direction of travel of the ball. How fast in the wagon going.

Explanation

To solve the problem, we will apply the principle of conservation of linear momentum. According to this principle, the total momentum before the collision is equal to the total momentum after the collision.

### Step-by-Step Solution:

1. **Identify the given values:**
- Mass of the basketball (m_b) = 1.2 kg
- Initial velocity of the basketball (u_b) = 7.5 m/s
- Final velocity of the basketball (v_b) = 3.8 m/s (after bouncing off)
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