Question

Assertion: The work done against gravity by a porter carrying a box of 40 kg on his head and moving 50 m horizontally is zero.

Reason: The direction of motion is perpendicular to the direction of gravitational force, hence work done zero.

पर्याय

• If both Assertion and Reason are true and the Reason is correct explanation of the Assertion.

• If both Assertion and Reason are true, but Reason is not correct explanation of the Assertion.

• If Assertion is true, but the Reason is false.

• If Assertion is false, but the Reason is true.

Answer 1

If both Assertion and Reason are true and the Reason is correct explanation of the Assertion.

Explanation:

The porter moves the box horizontally, while gravity acts vertically downward. Since there is no displacement in the direction of gravity, the work done against gravity is zero. Therefore, the Assertion (A) is true.

The direction of displacement is perpendicular to the gravitational force. Since W = F s cos⁡ 90° = 0, no work is done against gravity. Therefore, the Reason (R) is true and correctly explains the Assertion.

Hence, both A and R are true and R is the correct explanation of A.