# Homework Help: Kinematic question

1. Sep 11, 2016

### KevinFan

1. The problem statement, all variables and given/known data
A car accelerates at 1.95m/s2 along a straight road. It passes two marks that are 28.0m apart at times t=3.95s and t=5.20s. What was the car's velocity at t=0?

2. Relevant equations

3. The attempt at a solution
t1=3.95s, t2=5.20s, d=28m, t=t12-t1=1.25s, a=1.95m/s2 v0=?
28m=v0*1.25s+1/2*1.95m/s2*(1.25s)^2
v0=21.2 m/s

Could anybody tell me where have I done wrong?

2. Sep 11, 2016

### PeroK

You've tried to calculate the velocity at $t = 3.95s$, although I think you made a mistake in that calculation.

3. Sep 11, 2016

### KevinFan

Thank you, now I see that the velocity I calculated is only the velocity at t= 3.95s:)