Question

The driver of a car traveling at 10.0 m/s along a straight road depresses the accelerator and uniformly increases her speed at a rate of 2.20 m/s2. How fast will the car be moving as it passes a parked police cruiser 90 m away?

Answer 1

(Assuming you are talking 90 meters and not miles)

Start with the known values:

V0 = 10m/s
X0 = 0m
a = 2.2m/s^2
Xf = 90m

Now just use the kinematic formula which allows you to solve for Vf:
\[Vf ^{2}=Vi ^{2}+2a(Xf-Xi)\] So it's \[Vf^2 = (10m/s^2)^2 + 2 (2.2m/s^2)(90m) = 496 m/s\]\[V = \sqrt{496}=22.27 m/s\]

Answer 2

Thanks a lot! that helped me :)