Oftentime we lost the charm of Engineering in theorical jungle. Let have some visualization unit for different physical parameters:
Avg walking speed: 4 mph
Avg running speed: jogging: 8-9 mph
sprinting: 13-14 mph
So, when a car speeding 70 mph it is actually moving 10times of your avg jogging speed.
my weight=85 kg, my mass=8.5kg
When you walk a 7 mph=3m/s