Question

Friction can be reduced on a road by _______.

• A. making the surface wet
• B. making the surface dry
• C. making the surface rubbery
• D. sprinkling sand on the surface

Answer 1

The correct option is A

making the surface wet

As compared to smooth surfaces, rough surfaces generally provides more friction. Hence, it is more effective in opposing the motion. Wetting the pitch road surface makes the surface smoother and hence reduces friction. On the other hand, making the surface dry or rubbery increases friction because of increase in roughness. Digging the surface will change the surface itself and mud below the road may be exposed.