I'll gladly hit a 450 gram[1] ball with my head, rather than a 110 kilogram linebacker[2][4]. Sure, the velocity of the ball is faster (average professional le

I'll gladly hit a 450 gram[1] ball with my head, rather than a 110 kilogram linebacker[2][4]. Sure, the velocity of the ball is faster (average professional level is ~27 m/s [3]) and the relation with that variable is squared (E = ½mv²), but linebackers still run at 7.6 m/s [4] Soccer ball kinetic energy: 164 Joules Linebacker kinetic energy: 3176 Joules That's already an order of magnitude difference, while not even counting the momentum and impulse: soccer balls are pretty elastic, compared to linebackers... 1 https://en.wikipedia.org/wiki/Ball_(association_football) https://en.wikipedia.org/wiki/Ball_(association_football) 2 https://www.sbnation.com/nfl/2014/2/22/5427038/nfl-combine-2014-weigh-in-results-for-linebackers https://www.sbnation.com/nfl/2014/2/22/5427038/nfl-combine-2... 3 https://www.quora.com/What-is-the-average-speed-of-a-soccer-ball-when-someone-kicks-it https://www.quora.com/What-is-the-average-speed-of-a-soccer-... 4 https://www.sbnation.com/nfl/2015/2/22/8085379/2015-nfl-combine-results-40-yard-dash-linebackers https://www.sbnation.com/nfl/2015/2/22/8085379/2015-nfl-comb...