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Physics · PYQ NEET UG 2017
हिन्दीTwo blocks A and B of masses \( 3\text{m} \) and \( \text{m} \) respectively are connected by a massless and inextensible string. The whole system is suspended by a massless spring as shown in figure. The magnitudes of acceleration of A and B immediately after the string is cut, are respectively:
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Correct answer · Option B
\( \frac{g}{3}, g \)
Explanation
Immediately after the string is cut, the spring force remains unchanged at \( 4mg \). For block A of mass \( 3m \), net force is \( 4mg - 3mg = mg \), so \( a_A = \frac{g}{3} \). For block B, tension becomes zero, so it falls freely under gravity with \( a_B = g \).
