State and explain, with examples, how friction can help the cause of motion in certain situations.
Some of the examples are as follows-
a) When we walk, we push the ground under our feet in the backward direction, the friction then provides forward reaction and it is the main cause of the motion.
b) Vehicles run on the road due to the friction between tyres and the road.
c) Friction also helps in writing by moving a pen on a paper.