a driver travels 4.25 km in two minutes. if the driver's initial velocity is 20m/s, what is the acceleration

Recall the definition of average velocity:

average v = ∆x / ∆t

The driver moves a distance of ∆x = 4.25 km = 4250 m in 2 min = 120 s, so the average velocity is

average v = (4250 m) / (120 s) ≈ 35.4 m/s

Under constant acceleration, the average velocity can also be computed by taking the average of the initial and final velocities:

average v = (initial v + final v) / 2

Solve for (final v) :

35.4 m/s = (20 m/s + final v)/2

final v ≈ 50.83 m/s

Recall the definition of average acceleration:

average a = ∆v / ∆t

Solve for a :

a = (50.83 m/s - 20 m/s) / (120 s)

a ≈ 0.257 m/s²

a and c

c is 100% but i am confused in a

its lower due to the doppler effect.: apex