Question

Block A of weight 100 N rests on a frictionless inclined plane of slope angle ${30}^{\circ }$ as shown in the figure. A flexible cord attached to A passes over a frictionless pulley and is connected to block B of weight W.

Find the weight W for which the system is in equilibrium.

• A. 25 N
• B. 50 N
• C. 75 N
• D. 100 N

Answer 1

The correct option is B 50 N


As the system is in equilibrium,
$\therefore$ T = W …(i)
and $T=mgsin{30}^{\circ }$ …(ii)
From (i) and (ii), we get
$W=mgsin{30}^{\circ }=\left(100N\right)\times \frac{1}{2}=50N$