Answer to Question #3997 in Mechanics | Relativity for ekekekekekeke

Question

Two cars travel simultaneously at a common point. Car A travels at a rate of 25 m/s and accelerates at 2.5 m/s2 . Car B starts from rest and accelerates at 7.5 m/s2. How long will the two car cover the same displacement?

Answer 1

Let's construct the system of two equations of motion, for the car A and B respectively:
x = x₀ + v₀t + a₁t²/2
x = x₀ + a₂t²/2


0 + 25t + 2.5 t²/2 = 0 + 7.5t²/2
25t = 5t²/2
t = 10 sec