Three blocks with masses m, 2m and 3m are connected by strings, as shown in the figure. After an upward force F is applied on block m, the masses move upward at constant speed v. What is the net force on the block of mass 2m? (g is the acceleration due to gravity)

Home » Three blocks with masses m, 2m and 3m are connected by strings, as shown in the figure. After an upward force F is applied on block m, the masses move upward at constant speed v. What is the net force on the block of mass 2m? (g is the acceleration due to gravity)

Physics | Physics

Three blocks with masses m, 2m and 3m are connected by strings, as shown in the figure. After an upward force F is applied on block m, the masses move upward at constant speed v. What is the net force on the block of mass 2m? (g is the acceleration due to gravity)

Option A 6 mg
Option B zero
Option C 2 mg
Option D 3 mg

Solution:

The correct option is Option B
We know that, F = mass×acceleration
According to the question, the blocks are moving with constant velocity hence there will be no acceleration. Therefore, we have:

F(net) = ma = 0 since acceleration is zero

i

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