Question bank/JEE Main/Physics

JEE MainPhysicsModerate

Two blocks of masses 2 kg and 4 kg are connected through a massless
inextensible string. The

co-efficient of friction between 2 kg block and ground is 0.4 and the

coefficient of friction between 4 kg block and ground is 0.6. Two forces

F1 = 10 N and F2 = 20 N are applied on the blocks as shown in the

figure. Calculate the frictional force ( in N )between 4 kg block and

ground (Assume initially the tension in the string was just zero before

forces F1 and F2 were applied)

[IMAGE] 2 kg 4 kg 2 kg

0.4 4 kg

0.6 F1 = 10 N F2 = 20 N

4 kg (, F1 F2 )


Show answer and solution
System will not move (Equilibrium)
For equilibrium of 2 kg block

[IMAGE] 10 = 8 + T

⇒ T = 2N

For equilibrium of 4 kg block

[IMAGE] T + f2 = 20

⇒ f2 = 18 N

TOPIC: NLM

SUB TOPIC: FRICTION


Source: Grass-G / P-03 Paper 1 (Physics) Eng. + Hindi 24-8-2020.docx

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