A particle is moving in a circular path of radius r. The displacement after half a circle would be

Options

A. zero
B. `pi`r
C. 2r
D. `2pi` r

Explanation

To solve the problem of finding the displacement of a particle moving in a circular path of radius \( r \) after it has moved half a circle, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Circular Path**:
- The particle is moving along a circular path with a radius \( r \). Let’s denote the center of the circle as point \( O \).

2. **Identify Initial and Final Points**:
...