Question

A train is moving towards East with a velocity of 72 kmph. Its velocity is changed to 90 kmph
towards West. Find the change in velocity of the train.

a) – 20 ms-1 due East b) -25 ms-1 due East c) + 20 ms due East d) - 45 ms-1 due East​

Answer 1

Answer:

Take, east direction

i

^

and west direction −

i

^

Velocity of car and train, V

c

=54(−

i

^

)kmphandV

t

=72

i

^

kmph

Relative velocity of car with respect to train,

V

ct

=V

c

−V

t

=−54

i

^

−72

i

^

=−126

i

^

∣V

ct

∣=126kmph=126×

18

5

=35ms

−1

Hence, magnitude of velocity of car with respect to person sit in train is 35ms

−1