One 75-watt bulb gives more light than three 25-watt bulbs.
57
Airports that are at higher altitudes require a longer airstrip due to lower air density.
39
Iron weighs more after it rusts.
16
Sound travels about 4 times faster in water than in air.
408
For every gallon of sea water, you get more than a quarter pound of salt.
45
A coal power station puts 100 times more radiation into the air than a nuclear power plant producing the same amount of energy.
7
One cubic foot of gold weighs more than 1,200 pounds!
78
In Arizona, a solar wind energy tower has been proposed that would generate as much energy as the Hoover Dam.
5