Question

Two parallel rail tracks run north south.Train A moves north with a speed of 54km/h and train B moves south with a speed of 90km/h.What is the (i) relative velocity of B with respect to A?(ii) relative velocity of ground with respect to B?

Answer 1

Answer:

a.

v

BA

=

v

B

-

v

A

Hence, velocity of train B w.r.t train A is 144 km/h toward south.

b. Velocity of ground w.r.t. B

v

g,B

=v

g

−v

B

= 0 - 90$$

v

g,B

= -90 km/h

Hence, velocity of ground w.r.t train B is 90 km/h towards north.

c.

v

m,g

=

v

m,A

+

v

Ag

= 18 - 54 = -36 km/h

Hence, velocity of monkey will be 36 km/h toward north.