Armadillos have an unfortunate defense mechanism that gets them slaughtered in large numbers on Texas roads. They freeze at the first sign of danger (like an oncoming car) and then attempt to scare their attacker by jumping vertically at the last minute. The average Kenworth truck is not impressed and carnage ensues. If an armadillo can leap to 0.5m height, how fast must he be moving vertically when his feet just lift off the pavement?