A car is traveling with a constant speed when the driver suddenly applies the brakes, giving the car a deceleration of 3.50 m/s2. If the car comes to a stop in a distance of 30.0 m, what was the car's original speed?
Let's find the time elapsed to stop the car:
D = aT²/2 ==> T = √(2D/a) = √(2*30[m]/3.5[m/s²]) ≈ 14.49 [s].
So, the car's original speed was
V = aT ≈ 3.5[m/s²]*14.49[s] ≈ 50.72 [m/s].