Question

A passennger on a bus moving with uniform velocity lurches forward when the bus stops suddenly. Explain.?

Answer 1

That is an example of Newton's First Law of Motion, an object in motion will remain in motion unless acted on by another force. Even though the bus stopped quickly, the passenger's body was still in motion. Either a seatbelt or the seat in front of the passenger was the force that stopped the person's forward motion.

Newton's Second Law of Motion is at play here as well. F=ma or Force equals mass times acceleration.

You can also see Newton's Third Law of Motion at play as well. For every action there is an equal and opposite reaction. If the passenger is wearing a seatbelt, then when the bus comes to a stop the passenger pulls on the seatbelt and the seatbelt pulls on the passenger.

Answer 2

Due to inertia of motion of the upper part of the body of passenger.

Step-by-step explanation:

Passenger on a moving bus with uniform velocity lurches forward when the bus stops suddenly because when the bus was in uniform motion his body was in the state of inertia of uniform motion and when the brakes are applied suddenly to stop it still continues to be in motion while the bus stops within a fraction of seconds hence the passenger leans forward.

• The lower part of the body of the passenger is in proper contact with the rigid seat of the bus structure but the upper part is loosely supported and when the brakes are applied the lower part of the body comes to rest along with the bus but the upper part feels the motion for a longer time duration and the passenger leans forward.