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

Given horizontal force F = 10 N and coefficient of friction between block and wall (µ)=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 =µR=0.2×10=2 N.