Question

Three sides A, B and C are moving in a straight line in same direction such that relative velocity of A wrt B is 2m/s, relative velocity of B wrt C is -5m/s. Find relative velocity of C wrt A. Also write which body is moving in b/w of remaining two bodies.

Answer 1

Relative velocity of A and B: $V_{AB}=V_A-V_B=2m/s$..(1)

Relative velocity of B and C:$V_{BC}=V_B-V_C=-5m/s$..(2)

Adding (1) and(2)

$V_A-V_B+V_B-V_C=2-5$

$V_A-V_C=V_{AC}=-3ms/$

Relative velocity of C w.r.t A

$V_{CA}=V_C-V_A=-V_{AC}=3m/s$

we have:

$V_{AB}=2m/s,V_{BA}=-2m/s$

$V_{AC}=-3m/s,V_{CA}=3m/s$

$V_{BC}=-5m/s,V_{CB}=-V_{BC}=5m/s$

$V_{AB}$ is positive ans $V_{AC}$ is negative.

Therefore A is moving in between of remaining two bodies.