# Acceleration vectors (quick question)

1. Feb 13, 2006

### nick727kcin

this is the last thing that i dont really get. did i draw these acceleration vectors correctly?

thanks

2. Feb 13, 2006

### Staff: Mentor

It depends on the details of the motion, but it looks like you've got the idea. If the car moves at a constant speed around the curve, the only component of acceleration will be perpendicular to the motion (also called "radial" or "centripetal"). But if, as you are showing, the car's speed is increasing, then there will be a parallel (or tangential) component of acceleration as well.

3. Feb 13, 2006

### Staff: Mentor

I almost forgot: One thing that's not accurate in your diagram is the length of the total acceleration vector. The total acceleration is the vector sum of the two components, so it's got to be much longer than what your diagram shows. (Looks to me like the total vector is smaller than the perpendicular component. )

4. Feb 13, 2006

### marlon

YES.

You need to remember this :
Velocity is a vector. One can change a vector in TWO ways :
1) one can change the magnitude of the vector
2) one can change the direction of the vector

The tangential component does (1) (ie the velocity gets bigger or smaller)
The centripetal component does (2) (ie the actual circular orbit)

marlon