# Would like to know a few basic things ^^

1. May 7, 2006

### crays

Would like to know a few basic things ^^"

Hi , i'm 4 months new to physics . I'm not sure of something , mind if you all tell me ?

I would like to know :
The meaning of momentom (not sure the spelling)
The different of velocity and acceleration
How to count acceleration , velocity , displacement in a ticker tape

THANKS alot =) .

2. May 7, 2006

### Hootenanny

Staff Emeritus
Momentum, in classical mechanics, is simply the mass of a body multiplied by it's velocity; p = mv and is a conserquence of Newton's first law. Where no external forces act momentum is always conserved. Momentum can also be applied to rotating object in the form of angular momentum. In relativity and quantum mechanics momentum has a slightly difference meaning. More information is available here;
http://en.wikipedia.org/wiki/Momentum
http://scienceworld.wolfram.com/physics/Momentum.html

The difference between velocity (v) and acceleration (a) is quite simple. Velocity is the rate of change of displacement (s), with respect to time (t), thus;

$$v = \frac{ds}{dt}$$

Acceleration is the rate of change of velocity with time, thus;

$$a = \frac{dv}{dt} = \frac{d^{2}s}{dt^{2}}$$

As for the third question, I will leave than as an exercise for you, as it is an aplication of the above discussion.

~H