Question

A train starting from rest attains a velocity pf 72 km      h-1=hours inverse      in 5 minutes. assuming that the acceleration is uniform, find
(i) the acceleration and
(ii) the distance travelled by the train for attaining this velocity

Answer 1

a = v-u/t
a = 72000 - 0 / 5X60
a = 72000 / 300
a = 240 m per second square
By II equation of  motion -
s = ut + 1/2 a t x t
s = 1/2 x 240 x 300 x 300
s = 120 x 90000 = 10800000 m = 10800 km

Answer 2

(a)
a = change in velocity/time
we mulipy it by 60 to make it in seconds-5*60
final velocity-72
a = 72000 - 0 / 5X60
a = 240 m/second square
(b)
s = ut + 1/2 a t * t
s = 120 * 90000 = 10800000 m
 = 10800000/10000
=1080km