In high school I got into a car accident while I was waiting for a light to turn green after leaving lacrosse practice. The accident ended up totaling my car when a car that got t-boned in the intersection flipped onto my stationary car. In order to examine the physics of this, I will consider it an inelastic collision, and only consider the collision between my car and the car that got hit in the intersection, not the car that initially hit the car in the intersection. Below I calculated how fast my car was moving after it was hit.
The car that hit me was a chevy tahoe. m1=2429 kg
I was driving a honda fit m2=1140 kg
the tahoe was going 15 mph or 6.7 m/s
m1v1 + m2v2 = (m1 + m2)vf
(2429)(6.7) + 0 = (2429 + 1140)vf