Answer:
15 mph west
Step-by-step explanation:
Velocity of car 1 with respect to ground, V1,o = 45 mph west
Velocity of car 2 with respect to car 1, V2,1 = 30 mph east
Take east direction as positive direction and west direction as negative direction.
By use of formula of relative velocity,
Velocity of car 2 with respect to car 1 is given by
V2, 1 = V2,o - V1,o
30 = V2,o - (-45)
V2,o = 30 - 45 = - 15 mph
It means the velocity of car 2 with respect to ground is 15 mph towards west.