According to Newton's 3rd law, the forsces exert on each other are always equal in magnitude and opposite in direction. thus we define the total momentum of a system between two blocks of masses m1,m2 and v1,v2 as momentum=mv1+mv2
hence we arrive at the conservation of momentum,this states when no resultant force acts upon a system of bodies, and the total momentum of the stystem remains unchanges
total momentum before= total momentum after
elastic collisions are when the interaction forces between two bodies are conserved, the Ek of the system is the same after the collison as before the collison. therefore Ek is conserved
Inelastic collisions is a collision in which the total Ek of the system after the collision is less than the Ek before the collision. in one kind of inelastic collision, the colliding bodies stick together and move as one unit after the collison.
To determine wheather or not a collision is elastic or inelastic find the Ek before and the Ek after.If it is not conserved it is inelastic if it is it is elastic
Problem solving stategy for elastic collison
a) find the total momentum/Ek before collison
b)find the total momentum/Ek after
c) remember to consider a) = b) in problem solving
problem solving strategy for inelastic collision
Consider two masses Ma and Mb right before a collison then
a)find the total momentum before collision
i) MaVa1+MbVb1
b) find the total momentum after the collision
ii)(Ma+Mb)V2
c) remember to consider a) = b)
iii) remember they stick together in an inelastic collision for part b) and a) not equal to b), in the case of their kinetic energies
if the masses and velocities are known then we can compute the final velocity. suppose we have a body of mass Ma and initial velocity V1 and it collides inelastically with a body of mass Mb initially at rest
INITIALLY
(MaV1+Mb*o)
FINALLY
(Ma+Mb)V2
*After the collision the two bodies have a common velocity V2
HOPE THIS HELPS YOU