OnlineCBT
Physics · WORK, ENERGY AND POWER
हिन्दीA force \( \mathbf{F} = (4\hat{\mathbf{i}} + 3\hat{\mathbf{j}} - 2\hat{\mathbf{k}})\text{ N} \) acts on a particle, displacing it from \( \mathbf{r}_1 = (2\hat{\mathbf{i}} - \hat{\mathbf{j}} + 3\hat{\mathbf{k}})\text{ m} \) to \( \mathbf{r}_2 = (5\hat{\mathbf{i}} + 3\hat{\mathbf{j}} - \hat{\mathbf{k}})\text{ m} \). The work done by the force is:
Correct answer · Option 2
\( 32\text{ J} \)
Explanation
Displacement \( \mathbf{d} = \mathbf{r}_2 - \mathbf{r}_1 = (3\hat{\mathbf{i}} + 4\hat{\mathbf{j}} - 4\hat{\mathbf{k}})\text{ m} \). Work done \( W = \mathbf{F} \cdot \mathbf{d} = (4)(3) + (3)(4) + (-2)(-4) = 12 + 12 + 8 = 32\text{ J} \).
