MCQ
A block of mass $m$ is pulled along a horizontal surface by applying a force at an angle $\theta $ with the horizontal. The friction coefficient between the block and surface is $\mu$. If the block travels at a uniform velocity , then work-done during its displacement $d$ is
- A$\frac{{\mu \,mg\,d}}{{\sin\, \theta }}$
- B$\frac{{\mu \,mg\,d}}{{\cos \,\theta }}$
- C$\frac{{\mu \,mg\,d}}{{\cos \,\theta - \mu \sin \,\theta }}$
- ✓$\frac{{\mu \,mg\,d}}{{\cos\, \theta + \mu \sin \,\theta }}$
