Question

A 1000 kg car travelling at 25m/s south collides head-on with a 2250 kg car travelling at 10m/s in the opposite direction. They stick together after collision. Which way does the wreckage move? What is their final velocity?

Answer 1

i don't know teacher?

Answer 2

m1 = 1000kg
vi1 = -25m/s
m2 = 2250kg
vi2 = 10m/s
vf = ? m/s
(m1*vi1)+(m2*vi2)=(m1+m2)vf
vf=[(m1*vi1)+(m2*vi2)]/ [m1+m2]
vf=[(1000*-25)+(2250*10)]/[1000+2250]
vf = -0.769m/s OR vf = 0.769m/s south