given that the total travelled is 1.4km and the acceleration is 4/s^2 for the first T seconds, find: (a) the value of V, (b) the value of T
Is V the final velocity, the average velocity or what? Is the starting velocity zero?
I'll assume v is the final velocity, and that the acceleration is constant, in which case you can use:
(i) d = u*t +(1/2)*a*t^2 where d = distance, u = initial velocity, a = acceleration and t = time
(ii) v = u + a*t
I'll also assume the acceleration is 4 m/s^2
(i) 1400 = 0 +(1/2)*4*t^2 so t = sqrt(700) secs ≈ 26.5 secs
(ii) v = 0 + 4*t so v = 4*sqrt(700) m/s ≈ 106 m/s