A 2569 kg van runs into the back of a 827 kg compact car at rest. They move off together at 8.5 m/s. Assuming the friction with the road can be negligible, find the initial speed of the van.
M1V1=(M1+M2)VF
2569 x (V1) = 3396 x 8.5
V1 = 28866/2569
V1 = 11.24 m/s