1. The problem statement, all variables and given/known data If a 2000 lb car with a velocity of 88 ft/s has by my calculations a kinetic energy of 240 kJ. But for a 909kg car with a velocity of 26.73 m/s I calculate 324.7 kJ. Same velocity, same mass, different energy calculation. 2. Relevant equations English units: Kinetic energy(Ek)=.5(m)v^2; m= w/g; 2000 lb/32.2= 62.1 slugs: 5(62.1)(88)^2=240 kJ SI units: Ek=.5(m)v^2; kg-mass=kg; 1 kg/2.2lbs; 1 ft= .301 m: .5(909)(26.73)^2= 324.8 kJ 3. The attempt at a solution Am I getting my metric mass wrong? I'm having a very hard time wrapping my head around this. Please help me.