Solving Kinematic Questions: Velocity at t=0

[KevinFan]

Homework Statement

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?

Homework Equations

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?

 

[PeroK]

Homework Statement

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?

Homework Equations

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?

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

 

[KevinFan]

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

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