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jeahomgrajan
Mar31-08, 05:36 PM
1. The problem statement, all variables and given/known data
A sprinter has a velocity of 6.0m/s [s] at t=3.0s.
Five seconds later he is moving north with a speed of 4.0m/s. calculate the sprinters average acceleration


2. Relevant equations

average acceleration=change in velocity/elapsed time

3. The attempt at a solution

t1=3.0s, v1=6.0m/s[s], t2=8.0s, v2=-4.0m/s

Dick
Mar31-08, 05:56 PM
Your velocities (and acceleration) are vectors. They have a direction. What's vf-vi if vf=4m/s [n] and vi=6m/s [s]?

jeahomgrajan
Mar31-08, 06:05 PM
yeah i can jjust solve it, suppose i needed to change km/h/s to m/s^2

Dick
Mar31-08, 06:07 PM
yeah i can jjust solve it, suppose i needed to change km/h/s to m/s^2

I think you are thinking of a different problem. There's no km/hr in this one.

Snazzy
Mar31-08, 06:07 PM
yeah i can jjust solve it, suppose i needed to change km/h/s to m/s^2

Not sure how that relates to the question. They're already in standard units.

jeahomgrajan
Mar31-08, 06:08 PM
yeah i know im just asking generally