Energy of a random atomic and molecular is called molecules energy
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.
(1) friction is the force resisting the relative motion of solid surfaces , fluid layers and material elements sliding against each other.
(2) gravity is a science fiction .
(3) Resistance ::: is a property of a conductor by which the passage of current is opposed causing electric energy to be transformed into heat .
(4) viscosity is the quantity that describes a fluid.
(5)
They turn into a liguid. it is the opposite of evaporation. it didn't get hotter, it got cooler