# Vector Kinematics

1. Jan 24, 2007

### lkg5

Problem:
A particle starts from the origin at t=0 with an initial velocity of 5 m/s along the positive x axis. If the acceleration is -3i + 4.5j m/s^2 determine the velocity and position of the particle at the moment it reaches its maximum x coordinate.

Possible equations:
x= xo + vxo t + .5ax t^2

I guess I'm just confused on how to start. I do not think I plug numbers into an equation yet. Do I need to work with the numbers I have before using an equation?
Thanks for any help

2. Jan 24, 2007

### Mindscrape

You have a couple options. Find the angle that the acceleration vector is at, and use a coordinate transformation so that the acceleration travels in the e_x direction (this way is sort of roundabout and I wouldn't really suggest it, but thought I would throw it out to get you thinking). Or find the separate components and add them together.

Do you know calculus?

3. Jan 24, 2007

### lkg5

Am I just adding the components of the acceleration and the velocity? Would that give me my endpoint?

4. Jan 24, 2007

### Mindscrape

So I would focus on the e_x components first. Find what the maximum position will be in the e_x direction; determine how far the particle can go in the x direction with that initial push before it turns around. Then you can figure out what the e_y components are from the information in the e_x components.

5. Jan 25, 2007

### lkg5

I have figured it out.