Given data:
* The mass of the first car is 10 metric tons.
* The initial speed of the first car is 108 km/h
* The speed of couple of both the cars after the collision is 36 km/h.
* The initial speed of the second car is zero. ial
Solution:
By the law of conservation of momentum,
where m is the mass of first car, M is the mass of second car, u_1 is the initial velocity of first car, u_2 is the initial velocity of second car, v_1 is the final velocity of first car, and v_2 is the final velocity of second car,
Substituting the known values,
Thus, the mass of the second car is 20 metric tons.
Hence, option 2 is the correct answer.