(A) : A body can have acceleration even if its velocity is zero at a given instant of time.
(r) : A body is momentarily at rest when it reverses its direction of motion.

Options

A. Both (Assertion) and (Reason) are true and (Reason) is the correct explanation of (Assertion)
B. Both (Assertion) and (Reason) are true and (Reason) is not the correct explanation of (Assertion)
C. (Assertion) is true but (Reason) is false
D. (Assertion) is false but (Reason) is true

Answer

To solve the given question, we need to analyze both statements (A) and (r) regarding motion, acceleration, and velocity.

### Step-by-Step Solution:

1. **Understanding Statement (A)**:
- The statement claims that a body can have acceleration even if its velocity is zero at a given instant of time.
- This is true. Acceleration is defined as the rate of change of velocity. A body can be at rest (velocity = 0) but still experience a change in velocity, which means it has acceleration.

2. **Understanding Statement (r)**:
- The reason given is that a body is momentarily at rest when it reverses its direction of motion.
- This is also true. When an object changes direction, it must come to a momentary stop (velocity = 0) before it starts moving in the opposite direction.

3. **Example for Clarification**:
- Consider the example of a ball thrown upwards. As it rises, it slows down due to gravitational acceleration (g) until it reaches its maximum height, where its velocity is 0. However, the acceleration due to gravity is still acting on it, pulling it back down.
- At the maximum height, the ball is momentarily at rest, but it is about to reverse its direction due to the acceleration acting on it.

4. **Conclusion**:
- Both statements (A) and (r) are correct. The reason (r) correctly explains the assertion (A) because the momentary rest at the peak of motion is due to the acceleration acting on the body.

### Final Answer:
Both assertion (A) and reason (r) are correct, and the reason is the correct explanation of the assertion.

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