A man is standing on a boat in still water. If he walks towards the shore the boat will

Options

A. move away from the shore
B. remain stationary
C. move towards the shore
D. sink

Answer

To solve the problem of what happens to the boat when a man walks towards the shore, we can analyze the situation using the concept of conservation of momentum and the center of mass.

### Step-by-step Solution:

1. **Understand the System**:
- We have a man standing on a boat in still water. The boat is initially at rest.

2. **Identify the Movement**:
- The man begins to walk towards the shore. This means he is exerting a force on the boat in the opposite direction.

3. **Conservation of Momentum**:
- Since there are no external forces acting on the system (man + boat), the total momentum of the system must remain constant. Initially, the momentum is zero because both the man and the boat are at rest.

4. **Define Variables**:
- Let the mass of the man be \( m \) and the speed at which he walks towards the shore be \( v \).
- Let the mass of the boat be \( M \) and the speed at which the boat moves away from the shore be \( v' \).

5. **Set Up the Momentum Equation**:
- The initial momentum of the system is zero:
\[ 0 = m \cdot v - M \cdot v' \]
- Rearranging gives:
\[ m \cdot v = M \cdot v' \]

6. **Direction of Motion**:
- The man walking towards the shore causes the boat to move in the opposite direction (away from the shore) to conserve momentum.

7. **Conclusion**:
- Therefore, when the man walks towards the shore, the boat will move away from the shore.

### Final Answer:
The boat will move away from the shore.