Answer:
Let their direction of motion of bus A is iˆ then v⃗ A=(20m/s)iˆ
(a) Relative velocity of A w.r.t. B =v⃗ AB=V⃗ A−v⃗ B= (actual velocity of A)-(velocity of B)
=(20m/s)iˆ−(15m/s)iˆ=5m/siˆ
i.e. A is moving with speed 5m/s w.r.t B in iˆ direction.
(b) Relative velocity of B w.r.t A=v⃗ BA=v⃗ B−v⃗ A= (Actual velocity of B)-(velocity of A)
=(15m/s)iˆ−(20m/s)iˆ=(−5m/s)iˆ=(5m/s)(−iˆ)
i.e. B moving in −iˆ direction w.r.t A, at speed 5 m/s
