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Physics · LAWS OF MOTION
हिन्दीIn the block and trolley system shown in the figure, a trolley of mass \( 20\text{ kg} \) on a rough horizontal table is connected by a light string passing over a frictionless pulley to a hanging block of mass \( 3\text{ kg} \). The coefficient of kinetic friction between the trolley and the surface is \( \mu_k = 0.04 \). Taking \( g = 10\text{ m/s}^2 \), the tension \( T \) in the string while the system is accelerating is:
Correct answer · Option 2
\( \frac{624}{23}\text{ N} \)
Explanation
For 3 kg block: \( 30 - T = 3a \). For trolley: friction force \( f_k = 0.04 \times 200 = 8\text{ N} \), equation \( T - 8 = 20a \). Adding equations: \( 22 = 23a \Rightarrow a = \frac{22}{23}\text{ m/s}^2 \). Tension \( T = 30 - 3(\frac{22}{23}) = \frac{624}{23}\text{ N} \approx 27.13\text{ N} \).
