A car initially traveling at 15m/s accelerates at a constant rate of 4.5m/s^2 over a distance of 45m. How long does it take the car to cover this distance ?

Question

That is the exact question. 

Answer 1

I am not sure why nobody answered your question and it probably won't help now. Buuuut, I went ahead and solved it:

Use two kinematic equations: v_f = v₀ + at & v_f² = v₀ + 2aΔx

1st find the final velocity using the second eqn. And, then plug that into the first equation and solve for time.

a = 4.5m/s²

initial velocity= 15m/s

Δx = 45m

v_f² = v₀ + 2aΔx = 15² +2(4.5)(45) = 630=

v_f = √630 ≅25.1 m/s

Manipulating our 1st equation we get: (v_f - v₀)/a = t

t = (25.1 - 15)/4.5 = 2.24 s