Two blocks A and B of masses 3m and m respectively are connected by a massless and inextensible string. The whole system is suspended by a massless sp - Physics MCQ NEET 2017 2026 | ExamTest.live

hardMCQNEET 20172026Physics

4 marks (−1)

Two blocks A and B of masses 3 m and m respectively are connected by a massless and inextensible string. The whole system is suspended by a massless spring. The magnitudes of acceleration of A and B immediately after the string is cut, are respectively:

Solution & Step-by-step Explanation

Before cutting the string:Equilibrium of B : T = m g .Equilibrium of A : k X = T + 3 m g = 4 m g .Immediately after cutting the string:For B : Net downward force is its weight m g (as T becomes 0). a_{B} = \frac{m g}{m} = g (downward).For A : The spring force k X remains 4 m g (spring force doesn't change instantly). Net upward force F_{n e t} = k X - 3 m g = 4 m g - 3 m g = m g . a_{A} = \frac{m g}{3 m} = \frac{g}{3} (upward).

Try it yourself before checking the explanation above.

Two blocks A and B of masses 3 m and m respectively are connected by a massless and inextensible string. The whole system is suspended by a massless spring. The magnitudes of acceleration of A and B immediately after the string is cut, are respectively:

g, \frac{g}{3}

\frac{g}{3}, g

g, g

\frac{g}{3}, \frac{g}{3}

Practice with timed mock tests and track your performance across Physics.