Explain how can you measure frictional force?

Frictional force can be measured by spring balance method.

SPRING BALANCE METHOD:

1. Place a wooden block on a table and connect it to a spring balance. Ensure that the spring is parallel to the table.

2. Pull the spring balance slowly until the block begins to slide.

3. The load on the spring balance when the block begins to slide is a measure of the static friction.

4. The reading on the spring balance when the block continues to slide is a measure of the sliding friction.

5. We can also measure the coefficient of friction ;

μ = spring force/normal force.

(OR)

Frictional force can be measured if we know he friction coefficient of a surface. Consider a surface having a coefficient of friction as μ.

Frictional force = μ × Normal force acting on the surface(load)