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Physics · LAWS OF MOTION
हिन्दीA trolley of mass \( 18\text{ kg} \) on a rough horizontal surface (\( \mu_k = 0.05 \)) is connected by a light inextensible string passing over a smooth pulley to a vertically hanging mass of \( 2\text{ kg} \). Taking \( g = 10\text{ m/s}^2 \), the common acceleration of the system is:
Correct answer · Option 1
\( 0.55\text{ m/s}^2 \)
Explanation
Kinetic friction force on trolley \( f_k = \mu_k m_1 g = 0.05 \times 18 \times 10 = 9\text{ N} \). Net force driving motion \( F_{net} = m_2 g - f_k = 20 - 9 = 11\text{ N} \). Acceleration \( a = \frac{11}{18 + 2} = \frac{11}{20} = 0.55\text{ m/s}^2 \).
