/jp/ - Otaku Culture

>>10339734
i was just thinking about this and something is bothering me

case 1: you're in a vehicle going east at 50 km/h.
speed is 50 km/h
case 2: you're in a vehicle going north at 50 km/h.
speed is 50 km/h
case 3: you're in a vehicle going east at 50 km/h, which is in another vehicle going east at 50 km/h.
speed is 100 km/h
case 4: you're in a vehicle going east at 50 km/h, which is in another vehicle going north at 50 km/h
speed is (50^2+50^2)^(1/2) = 70.71?

what the fuck? how does that make sense? it's not like the two vehicles are ever moving against each other in either case 3 or 4, but the end result is much different.