Question

Why we cannot write with a pencil on a glass sheet

Answer 1

Hey there !

Writing is possible due to friction between the lead of the pencil and the surface of the paper. Because of the same reason we cannot write on glass as the friction between the lead and glass is not that much to imprint on paper.

Hope it helps you !

Answer 2

We are able to walk on ground because friction between the sole of our shoes and ground prevents us from slipping over the ground.To take a step forward during walking ,we lift one foot Off the ground and push the ground backwards with the other foot.If there were no friction between the sole of our shoe and ground, then our shoe on the ground would slip backwards.Since we push the ground backwards, the force of friction acts in the opposite direction, forward direction, and prevents our foot from slipping backward.