Question

What forces are used when writing on a chalk board? Why?

Answer 1

Two forces act while writing on the blackboard.

1) Frictional force

2) Static force

Frictional force is applied everytime we write anything.

But in second case, Static force allow the chalk powder to stick to the blackboard inspite of gravitational force acting on it.

Answer 2

The forces used when writing on blackboard are:

1. Static force,

& 2. Frictional force.