The average home creates more pollution than does the average car.
33
When you walk down a steep hill, the pressure on your knees is equal to three times your body weight.
199
Sound travels fifteen times faster through steel than through air.
134
At room temperature, the average air molecule travels at the speed of a rifle bullet.
55
Pumice is the only rock that floats on water.
14
The average temperature at 40,000 feet above sea level is -60 F.
56