Q 11-05-023NEETEAMCET 2012 (Medical)Easy
The displacement of a body is $(5\hat{i} + 3\hat{j} - 4\hat{k})$ m due to the action of a force $(6\hat{i} + 6\hat{j} + 4\hat{k})$ N on it for $5$ s. The power in watt is
Answer: (C) $6.4$
Concept. $P = \dfrac{\vec F \cdot \vec s}{t}$.
Step 1. Work. $30 + 18 - 16 = 32$ J.
Step 2. Power. $\dfrac{32}{5} = 6.4$ W.
Answer. $6.4$ (Option C).
Solution by Sreeraj P, M.Sc Physics