Question

A $60\, kg$ weight is dragged on a horizontal surface by a rope through a distance of $2m$. If coefficient of friction is $\mu =0.5,$ the angle of rope with surface is $60^{\circ}$ and $g=9.8\,m/{s}^{2},$ then work done is

• A. 294 J
• B. 15 J
• C. 588 J
• D. 197 J

Answer 1

Answer: (A)

294 J

Answer 2

Work =force $\times$ displacement $=F_{s} \cdot d$ $=F_{s} d \cos \theta$ $=\mu R d \cos \theta\,\,\, \left(F_{5}=\mu R\right)$ $W=\mu m g d \cos \theta \,\,\,(R=m g)$ $=0.5 \times 60 \times 9.8 \times 2 \cos 60^{\circ}$ $=294\, J$