Answer: In the direction of the first car.
Step-by-step explanation:
Let the initial velocity of the first car be equal to U1 and the initial velocity of the second car be equal to U2
Given that the car is travelling with a positive velocity, and after it collides with another car moving with a negative velocity, the momentum before collision will be
M1U1 - M2U2
If the first car is still moving with a positive velocity, the second car will also be moving in the direction of the first car if the collision is inelastic collision.
Therefore, the direction of the second car will be positive direction if the collision is inelastic collision.