Question

A train starts from rest attains a velocity of 72km/h in 5 min the acceleration is uniform find 1)acceleration 2) distance travelled by the train to attain this velocity

Answer 1

1)Apply 1st eq. of motion. i.e. v=u+at
Herr u=0 and v=20m/s and t=300sec.
Putting the vakues in eq. we get a=20/300=0.067m/s2
2)apply third eq. v2=u2+2as. We get s=20*20/2*2/3=300m

Answer 2

first case
v= u+ at
20= 0+ 300a
20/ 300= a
1/ 15= a

second case
s= ut + 1/2at^2
s= 0+ 1/2 1/15×300×300
s= 30000m