What is momentum?

Question

Suppose Jane {random i know} jumps of a building.

Jane leaps and expeirences free fall for 3 sec. Then the bungee cord begins to strech reducing herr speed to 0 in 2 secoundss. but jane doesnt die! Jane weighs 100 kg and acceleration is 10 m per secound. If time=0 secounds, what would be the velocity and the momentum if jane has not jumped off yet? what would it be if the time was 5 sec. Please i need help.

Answer 1

Both answers are ZERO.

Before she jumps she is not moving, therefore has no momentum - from Momentum = mass x velocity.
If you have no velocity then you have no momentum.

After 5 seconds, again she is at rest meaning again velocity is zero (3 secs freefall + 2 secs for the rope to stop her)
So her momentum is zero if she isn't moving.

I weigh 80kg and am 6 ft tall so Jane is quite a heffer at 100kg wouldn't you say ???

Answer 2

Before she jumps her velocity is 0 and her momentum is zero. You said that at 5 seconds the bungee had reduced her speed to zero again, so her speed is 0 again and her momentum is 0 again. Soon she will be zooming up!

Don't ask me to do that!

Answer 3

Momentum is


In classical mechanics, momentum (pl. momenta; SI unit kg m/s) is the amount of mass moving, which can be written as the product of the mass and velocity of an object. For more accurate measures of momentum, see the section "modern definitions of momentum" on this page.

In general, the momentum of an object can be conceptually thought of as how difficult it is to stop the object, as determined by multiplying two factors: its inertia (the resistance of an object to being accelerated) and its velocity. As such, it is a natural consequence of Newton's first and second laws of motion. Having a lower speed or having less mass (how we measure inertia) results in having less momentum.

Momentum is a conserved quantity, meaning that the total momentum of any closed system (one not affected by external forces, and whose internal forces are not dissipative in nature) cannot be changed.

The concept of momentum in classical mechanics was originated by a number of great thinkers and experimentalists. René Descartes referred to mass times velocity as the fundamental force of motion. Galileo Galilei in his Two New Sciences used the term "impeto" (Italian), while Newton's Laws of Motion uses motus (Latin), which has has been interpreted by subsequent scholars to mean momentum. [citation needed]

Answer 4

http://education.yahoo.com/reference/dictionary/entry/momentum

there you go