Question

A block is sliding on a horizontal surface at a speed of $1m{s}^{-1}$. The friction offered by the surface on the block is 1 N. A horizontal force is applied to the block to increase its speed to $2m{s}^{-1}$. Now, the friction offered by the table will be:

• A. 1 N
• B. 2 N
• C. 3 N
• D. 4 N

Answer 1

The correct option is A 1 N

As the block is sliding on the horizontal surface, kinetic or sliding friction will be acting on it. On applying a horizontal force, the sliding friction or kinetic friction remains unchanged. Hence, kinetic friction will also remain unchanged, i.e., equal to 1 N.