A body is imparted motion from rest to move in a straight line. If it is then obstructed by an opposite force, then

Options

A. The body may necessarily change direction
B. The body is sure to slow down
C. The body will necessarily continue to move in the same direction at the same speed
D. None of these

Answer

To solve the problem step by step, we need to analyze the situation where a body is initially in motion and then subjected to an opposing force.

### Step-by-Step Solution:

1. **Identify Initial Conditions**:
- The body starts from rest and is then given an initial velocity \( V \) in a straight line.

2. **Introduce the Opposing Force**:
- An opposing force is applied in the opposite direction to the motion of the body. This force will affect the body’s motion.

3. **Determine the Effect of the Opposing Force**:
- According to Newton's second law, the net force acting on the body will cause it to accelerate. Since the opposing force is in the opposite direction, it will produce a negative acceleration (deceleration).

4. **Calculate the Acceleration**:
- Let’s denote the opposing force as \( F \). The acceleration \( a \) can be expressed as:
\[ a = \frac{F}{m} \]
- Here, \( m \) is the mass of the body. Since the force is opposing the motion, the acceleration will be negative:
\[ a = -\frac{F}{m} \]

5. **Analyze the Change in Velocity**:
- The change in velocity can be described by the equation:
\[ \frac{dV}{dt} = a \]
- Since \( a \) is negative, this implies that:
\[ \frac{dV}{dt} < 0 \]
- Therefore, the velocity \( V \) of the body will decrease over time.

6. **Conclusion on Motion**:
- The body will slow down due to the negative acceleration caused by the opposing force. Depending on the magnitude of the force, the body may eventually stop or continue moving but at a reduced speed.

7. **Consider Direction Change**:
- While the body is guaranteed to slow down, whether it changes direction depends on the magnitude of the opposing force relative to the body's initial momentum. If the opposing force is strong enough, it could reverse the direction of the body.

### Final Answer:
- The body is sure to slow down (Option 2 is correct).