Question
Three blocks will 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)
-
zero
-
2 mg
-
3 mg
-
6 mg
Solution
A.
zero
Since all the blocks are moving with constant velocity, then the net force on all blocks will be zero.
