A car starts from rest and travels a distance of 150 m in 15 s with a constant acceleration what is the velocity of the car after 15 s?

Here, we have

d = 150m, t = 15s, V0 = zero, acc. is constant

he wants Vf (final velocity) after 15s

we will use to 2 equations from the kinametics equation

the first one to get the acc. which is d = v0*t+0.5*a*t^2

v0=zero then d = 0.5*a*t^2

then a = 2*d / (t^2) = 4/3 m/s^2

we have the acceleration now so we can get the V through this Equation

V=v0+a*t

0 + 4/3 * 15 = 20 m/s