JEE Main & Advanced
Physics
NLM, Friction, Circular Motion
Question Bank
Self Evaluation Test - Laws of Motion
question_answer
Two blocks of masses 2 kg and 4 kg are attached by an inextensible light string as shown in the figure. If a force of 120 N pulls the blocks vertically upward, the tension in the string is (Take\[g\text{ }=\text{ }10\text{ }m{{s}^{-2}}\])
A)20N
B)15N
C)35N
D)40N
Correct Answer:
D
Solution :
[d] Acceleration of the system \[a=\frac{F-4g-2g}{4+2}=\frac{120-40-20}{6}\] \[=10\text{ }m{{s}^{-2}}\] From figure \[T-2g=2a\] \[T=2\left( a+g \right)=2\left( 10+10 \right)\] \[=40\text{ N}\]