Question

A train starting from rest, attains a velocity of 20 m/s in 2 minutes.Assuming that that the accelerations uniform, find acceleration and distance travelled by the train in 2 minutes.

Answer 1

Acceleration = v - u / t where v = final velocity, u = initial velocity and t = time taken.

Now, v = 20 ; u = 0 ; t = 2 mins = 120 s

20 - 0 / 120 = 1/6 ms-2





Now, for finding distance travelled s, we can use s = ut + 1/2 at^2

2 min=120 sec

Thereforeerefore, S = 0*120 + 1/2 * 1/6 * 120 * 120

= 0 + 60 * 20

= 60 * 20 = 1200 mts.




Alternate solution

2 min = 120s

v = u + at
20 = 0 + a*120
a = 20/120 = 1/6 m/s^2

S = ut + 0.5at^2
S = 0 + 0.5*1/6*(120)^2
S = 1200m
S = 1.2 km