why doesn't a bus move when you push it from inside?

Question

The bus doesn't move when you push it from inside but it does move when you push it from outside...... WHY?

Answer 1

The answer to this is that no system at rest can gain velocity without application of an external force. In this case, 'the bus' + 'you' constitute a system. If the bus were somehow frictionless and you walked from the back of the bus to the front, the bus would move backwards, just enough to keep the center of mass of you + the bus at the same point. Thus, to an external observer, it might indeed appear as though you had moved the bus (although static friction makes even this process too difficult to achieve in reality.)

In the case where you push against the inside of the bus, as has been mentioned, you are pushing the wall with your hands in one direction and by necessity pushing the floor with equal force in the opposite direction at the same time. Basically, this obeys the rule that an internal force will never cause an object to accelerate.

Answer 2

The reason the bus doesn't move when you are pushing on it from inside the bus is because you are using the bus itself as a platform for pushing. You have to be on another platform that is not part of the bus - like the street - to do your pushing. It's a little bit like not being able to pick up a pail that you are standing in.

Answer 3

Well Thats a waste of a question, but well I thank you for the two points, keep these coming.lol but answering your question cause well the bus is being puse forward by your hands but your feet are moving it backwards.I;m sure if you run as fast as you can from the front of the bus and jump so all your body hits the back of it. The bus might just move if enough people and weight was pt into it it might just roll a bit.

Answer 4

Because you're positioned relative to the bus - in essence part of the bus system's mass. In short, you are part of the bus itself when you are in it. If you used the floor as a brace and pushed on the seat, the most you could achieve is ripping the seat out of the floor.

Answer 5

u want to move the bus by keeping inside .

u can do it when u push the bus without pivoting the forces u give to the bus.

Answer 6

because you're pushing it with your hands, but your feet are pushing it just as hard in the opposite direction. The net force acting on the bus is 0.

Answer 7

Since you're bracing yourself against something that is a part of the bus, Newtonian physics states that the bus is pushing back against both your "brace point" and your "push point", preventing any work from being done.

Answer 8

a resultant force is needed for a body to move.if you are inside a bus you not only exert a force in forward direction with hands but also increase the normal force on the earth by your legs,due to which the frictional force increases resulting in nullifying the force you exert on the bus.so, the bus doesn"t move.

Answer 9

If the bus is shifting at a relentless velocity without acceleration, you will land in the top same place. If the bus is slowing down you will land at the same time with your ft greater in the direction of the front of the bus If the bus is rushing up you will land better back in the bus.

Answer 10

oh it moves. you can rock any vehicle.