A girl ridding a bicycle along a straight road with a speed of `5 ms^(-1)` throws a stone of mass 0.5 kg which has a speed of `15ms^(-1)` with respect to the ground along her direction of motion. The mass of the girl and bicycle is ` 50kg` . Does the speed of the bicycle change after the stone is thrown ? What is the change in speed, if so ?

Explanation

To solve the problem, we will use the principle of conservation of linear momentum. The momentum of a system remains constant if no external forces act on it.

### Step-by-Step Solution:

1. **Identify the initial conditions:**
- The girl and the bicycle have a combined mass of \( m_{gb} = 50 \, \text{kg} \).
- The initial speed of the girl and the bicycle is \( u = 5 \, \text{m/s} \).
- The mass of the stone is \( m_s = 0.5 \, \text{kg} \).
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