# Inertia or impulse

1. Oct 8, 2007

### calculus

hi...

a basic question... [ ppl are having heated arguments over this at home ]

" when u jump out of a moving bus.... u run a little distance"

why we do this? what is this phenomenon?

2. Oct 8, 2007

### Proggle

Before you jump, you are moving at the same speed as the bus.

When you jump off, this does not immediately change. While in the air, you are still moving in the same direction as the bus even though you are also falling towards the ground.

When you land, you still need a short distance for braking, just as if you want to stop while running.

Clear enough?

3. Oct 8, 2007

### TVP45

It's just deceleration. You want to slow down over as long a time as possible. You could always do like my sister and grab a hard object to stop you right away. Hurts, though.

4. Oct 10, 2007

### richard14

Dear Calculus probably you could say that is an impulse because your momentum is
changing with respect to the bus but i am sorry is not an impulse an impulse will be
if the bus would stop suddenly and your body will be ejected from the bus
and i dont think is inertia either because you see you are just jumping from the bus
the force of the bus is not acting on you. Inertia is the property of an object to remain at constant velocity unless acted upon by an outside force

5. Oct 10, 2007

### richard14

calculos am sorry my mistake absolutely this force will be inertia

6. Oct 10, 2007

### richard14

you see when yo jump from the moving bus your body runs a little bit forward because
you have a little bit of the bus momentum and that applies to the law of newton
the law of inertia