Question

Explain whya. A horse cannot pull a cart and run in empty spaceb. Passengers are thrown forward from their seats when a speeding bus stop suddenlyc. It is easier to pull a lawn mower than to push itd. A cricketer moves his hands backwards while holding a catch

Answer 1

For pulling a cart or for running, the horse pushes the earth with its feet and reaction of the earth makes it move in the forward direction. Since in empty space there is no reaction force, therefore the horse cannot run in empty space. A lawn mower is pulled or pushed by applying force at an angle.

This is due to the inertia which states that body will remain in motion/rest until an external force is applied on it. When bus get stopped suddenly, our lower part come to the rest but upper part remain in the motion. so we are suddenly pulled in the forward direction

for laawn---it is because when we pull/push a lawn mower, we apply a force in the direction of its handle which is at an angle with the ground. So there is always a component of force normal to the ground

A Cricketer moves his hands backwards during catching so as to take a longer time to stop the ball,this reduces the chances of injury.
According to Newton’s law of motion,
Force=Mass*(change in velocity\speed)/time
Greater the time used to stop the ball,lesser the impact of ball on hands and thus less chances of being hurt by ball and get injured.


I hope this will help you