Question

A train starts from rest and accelerates uniformly for 30 seconds to acquire a velocity of 30 metre per second. it travels with a velocity for 20 minutes driver now applies break and train retards uniformly to stop after 20 second, find the total distance covered by the train.

Answer 1

u=0 t=30 v= 30
v = u +at
30 = a 30
a=1 m/s
s = ut +1/2 at ^2
= 30 *15
= 450 m
now ,
20 ×60

Answer 2

First find acceleration

a=u-v/t

a = 30-0/30

a=1m/s

Using second equation

find distance traveled in this time

s=ut+1/2at^2

s=0X30+1X1X30X30/2

s=450 Meter

Now, find distance for 20 Minutes

s=vXt

s=30X20X60

60 To change minutes into seconds

s=36000 Meter

Now find distance when driver applies brakes

Using second equation,

s=ut+1/2at^2

s=30X20+1X1.5X20X20/2

s=900 Meter

Total distance=

450+36000+900

=37350 Meter

or

37.350 Kilometer