why do a passenger fall in the forward direction when a moving bus brakes to a stop and Falls backward when it accelerates from rest

When a bus starts moving suddenly the part of passengers body in contact goes forward but the upper portion of his body remain at rest as per the rule this is the reason why the passenger fall back

when a bullet is fired it exerts a pressure backward give reason

According to the third law of motion every action has opposite and equal reaction and both action and reaction work on different bodies when a bullet is fired out it exerts action force on the gun backward. This is the reason a man handling the gun is pushed backward

why do you fall in the forward direction when a moving bus brakes to a stop and Falls backwards when it accelerates from rest

When a moving vehicle carries a passenger both the vehicle and the passenger move with the same speed in the same direction when the vehicle stops suddenly the portion of assigner's body that remains in contact comes to rest but the upper part of the body wants to remain in the previous condition and hence it bends forward

explain why is is it difficult for a Fireman to hold a hose which ejects large amount of water at a high velocity

The water rushing out a pipe exerts a backward pressure. Since the velocity of water rushing through pipe remains very fast the backward pressure on the pipe too is very fast. As such it is very difficult for a Fireman to hold the pipe

why is it it advised to tie any luggage kept on the roof of a bus with a rope

The velocity of Air on the roof of a bus is felt very high. The luggage placed on the roof of a bus moves as fast as the bus when if fast moving bus change its direction the luggage placed over the roof may be  thrown away due to its inertia. Hence the luggage is tightly bound on the roof to protect it against falling away

in cricket a fielder gradually pulls his hands backward while taking a catch why

The fielder tries to spend more time to reduce the velocity of the ball. Thus the impact of fast ball on hand is reduced. In the body is checked suddenly the rate of change of momentum of the ball may be Tu Hai which can couch injury e in the hands of a fielder

if action is always equal to the reaction explain how horses can pull a cart

Leg of horse imposed pressure on ground at certain angle the Earth surface also impose similar force on the Leg of the horse in opposite direction the pressure imposed by Earth had two components vertical component and horizontal component the vertical component balance the weight of the horse and the cart the card is pulled forward due to origin till component