A Chevy van going 15mph rear-ends a950-kg Ford Aspire that is stopped at a light. (After the collision they are both going in the same direction). Assume the Aspiredriver didn’t have the brakes on and that there’s nofriction/air resistance. If the resulting velocity of the Aspireright after the collision is 18mph, and that of the van is 6mph, find the mass of the van.