Answer:
v=9.6 km/s
Explanation:
Given that
The mass of the car = m
The mass of the truck = 4 m
The velocity of the truck ,u= 12 km/s
The final velocity when they stick = v
If there is no any external force on the system then the total linear momentum of the system will be conserve.
Pi = Pf
m x 0 + 4 m x 12 = (m + 4 m) x v
0 + 48 m = 5 m v
5 v = 48

v=9.6 km/s
Therefore the final velocity will be 9.6 km/s.
It would be C as the law says "<span>Formally stated, </span>Newton's third law<span> is: For every action, there is an equal and opposite reaction. The statement means that in every interaction, there is a pair of forces acting on the two interacting objects. The size of the forces on the first object equals the size of the force on the second object."</span>
The answer is C because the three metals that are magnetic are iron, nickel, and cobalt, and it is metal so it is a conductor of electricity.