A rigid body moves a distance of 10m along a straight line under the action of a force 5N. If the work done by this force on the body is 25 joules, the angle which the force makes with the force makes with the direction of motion of the body is:

Options

A. `0^(@)`
B. `30^(@)`
C. `60^(@)`
D. `90^(@)`

Explanation

To solve the problem, we need to find the angle θ that the force makes with the direction of motion of the body. We can use the formula for work done by a force, which is given by:

\[ W = F \cdot d \cdot \cos(\theta) \]

Where:
- \( W \) is the work done (in joules)
- \( F \) is the magnitude of the force (in newtons)
- \( d \) is the distance moved by the body (in meters)
- \( \theta \) is the angle between the force and the direction of motion

### Step-by-Step Solution:

1. **Identify the given values**:
- Work done, \( W = 25 \, \text{J} \)
- Force, \( F = 5 \, \text{N} \)
- Distance, \( d = 10 \, \text{m} \)

2. **Substitute the values into the work done formula**:
\[ 25 = 5 \cdot 10 \cdot \cos(\theta) \]

3. **Simplify the equation**:
\[ 25 = 50 \cdot \cos(\theta) \]

4. **Solve for \( \cos(\theta) \)**:
\[ \cos(\theta) = \frac{25}{50} = \frac{1}{2} \]

5. **Find the angle \( \theta \)**:
\[ \theta = \cos^{-1}\left(\frac{1}{2}\right) \]
The angle whose cosine is \( \frac{1}{2} \) is \( 60^\circ \).

### Final Answer:
The angle which the force makes with the direction of motion of the body is \( 60^\circ \).