A: Average velocity can be zero, but average speed of a moving body can not be zero in any finite time interval.
R: For a moving body displacement can be zero but distance can never be zero.

• If both Assertion & Reason are true and the reason is the correct explanation of the assertion, then mark (1).
• If both Assertion & Reason are true but the reason is not the correct explanation of the assertion, then mark (2).
• If Assertion is true statement but Reason is false, then mark (3).
• If both Assertion and Reason are false statement, then mark (4).

To analyze the statements provided, let's break down the concepts of average velocity, average speed, displacement, and distance.

Understanding Average Velocity and Speed

Average velocity is defined as the total displacement divided by the total time taken. It can indeed be zero if the starting and ending positions of the object are the same, even if it has moved during that time.

Average Speed Explained

On the other hand, average speed is the total distance traveled divided by the total time. Since distance is always a positive value, average speed cannot be zero unless the object does not move at all.

Displacement vs. Distance

Displacement refers to the change in position and can be zero if the initial and final positions are the same. However, distance, which measures the total path traveled, will always be a positive value and cannot be zero if the object has moved.

Evaluating the Statements

• Assertion: Average velocity can be zero, but average speed cannot be zero in any finite time interval.
• Reason: For a moving body, displacement can be zero, but distance can never be zero.

Both the assertion and the reason are true. The reason correctly explains the assertion because it clarifies why average speed cannot be zero while average velocity can be.

Final Assessment

Based on the analysis, the correct choice is (1): both Assertion and Reason are true, and the Reason is the correct explanation of the Assertion.