Question

A horizontal force of 10 N in necessary to just hold a block stationary against a wall. The coefficient of friction between the block and the wall is 0.2. The weight of the block is

• A. 2 N
• B. 20 N
• C. 50 N
• D. 100 N

Answer 1

The correct option is A 2 N

Given horizontal force F = 10 N and coefficient of friction between block and wall $\left(\mu \right)=0.2$
We know that at equilibrium the horizontal force provides the normal reaction to the block against the wall. Therefore, the normal reaction to the block (R) = F = 10 N.
We also know that weight of the block (W) = Frictional force $=\mu R=0.2\times 10=2N$.
Hence, the correct answer is option (a).