Question

There are two identical blocks with weight W = 10 N each. The block-2 is attached with the block-1 with a massless string. You are pulling the block-1 with a force F = 5 N such that the blocks start moving. The frictional force on each block is f = 2.5 N. Find the tension on the string?

• A. 10 N
• B. 2.5 N
• C. 5 N
• D. 0 N

Answer 1

The correct option is B 2.5 N

After applying 5 N force all the blocks starts their movement. This means net force on each block is zero. For the 2nd block external forces are frictional force and tension on the string. As net force is zero so total frictional force on the 2nd block is equal to the tension on the string. So, tension on the string is 2.5 N.