Conservation of Momentum - Physics 101 / AP Physics 1 Review with Dianna Cowern

the difference in momentum isn't what makes the golf cart hurt less.  imagine that the electric truck is infinitely massive (!) and then find the best case for the golf cart and the worst case for the truck. the best case would be a perfectly inelastic collision. you probably weigh about 50 kg, and you're at rest, so with momentum conserved you and the cart will be moving at 5200 kg m/s / (260 kg + 50 kg) = 17 m/s. it lost [(20 m/s)^2 - (17 m/s)^2)] * 260 kg = 30 thousand joules of energy that you and the golf cart jointly ate. it's harder than you are, so it dents and you get squished. if the infinitely massive (momentous?) truck hits you at 1 m/s and you bounce off of it (likely) you'll be going 2 m/s afterwards, so you'll have gained (2 m/s)^2 * 50 kg = 200 joules of kinetic energy, which leaves you shaken, but not stirred.