Question

13. The initial velocity of a train which is stopped in 20 s by applying brakes (retardation
due to brakes being 1.5 ms-2) is
(a) 30 m s-1
(6) 30 cm-1
(c) 20 cm-1
(d) 24 ms -1
lined along with on⁸​

Answer 1

Answer:v=0 m

a=1.5ms-2

t=20s

u=v+at

As here is retardation so the acceleration will be taken in negative.

u=0-1.5 X20

=30m s-1.

30 m s-1

is your answer.......

Answer 2

a= 1.5m/s
V= 0 as it stopped
t=20seconds


I am applying the first equation of motion,
v=u+at
0=u+(1.5)(20)
0=u+30
u=30-0
u=30

Therefore the initial velocity is 30m/s.


Hope the answer helps you.

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