The insertion of extra atoms or molecules into an unsaturated hydrocarbon is called:

The correct answer is an addition reaction.  

A reaction in which two or more reactants come together to produce a single product is called an addition reaction. The product will comprise all the atoms, which were there in the reactants. The addition reaction takes place with unsaturated compounds.  

Hydrohalogenation is one of an example of the addition reaction, in which supplementation of a hydrogen atom and a halogen atom takes place with an unsaturated compound.  

(newtons first law)

conservation of momentum law states :

momentum before collision = momentum after collision

momentum p (kg-m/s)= mass * velocity

say moving car=1 000 kg, velocity = 10 m/s then p = 1 000*10= 10 000 kg-m/s

say still car = 2 000 kg, velocity = 0 m/s then p = 2 000* 0 = 0 kg-m/s

total momentum prior to collision = 10 000 + 0 = 10 000 kg-m/s

momentum after collision = 10 000 kg-m/s

mass now = 1 000 kg+2 000 kg = 3 000 kg

10 000 = 3 000 kg* velocity m/s

10 000/3 000 = velocity

3.33 m/s = velocity after collision

an impulse is a force applied over time , momentum is exclusive of external forces and a perfect collision is implied