1. The problem statement, all variables and given/known data a) KE=(1/2)(m)(v-u)2 Conversion: u = (31km/hr)(1hr/3600s)(1000m/km) = 8.61m/s v = (64km/hr)(1hr/3600s)(1000m/km) = 17.78m/s KE = (1/2)(1850kg)(17.782-8.612) = The Answer for a) b)Momentum= m(√(v2+u2)), v=14.17i u=11.39j = 1850(√(17.782+8.612)) = Answer for b) c)tan θ = (8.61/17.78) = Degrees South of East 2. Relevant equations p=mv Momentum= m(√(v2+u2)) 3. The attempt at a solution What I can't figure out is why they are taking the square root of the two squared numbers, can anyone help explain this? The question is asking for the magnitude of the momentum, but I thought that was p=mv.