First, convert your figures to SI units and scientific notation:

average radius = 6.374e6 m
average surface pressure = 0.76 mm Hg where density of Hg = 1.35e4 kg/sq.m

Second, calculate surface area (not volume):

area at surface = 4.pi.r^2 = 4.pi.(6.374e6)^2 = 5.1054494709e14 sq.m

Thirdly, convert presure from mm Hg to kg/sq.m :

pressure = 0.76 x 1.35e4 = 1.0264e4 kg/sq.m

Finally, get the weight:

weight = pressure x area = 1.0264e4 x 5.1054494709e14 =5.24023333693e18 kg

or 5,240,233,336,930,000 tonnes (5.24 quadrillion, using the American
idiom)

Published estimates range from 4.99 to 5.23 so this figure appears slightly
high. Your turn to discuss.

Either way, it is only about a millionth of the Earth's total mass.


"Nelson" wrote in message
oups.com...
The average radius of the Earth is 6,374kilometres.
The volume of a sphere is 4/3phi r3
Pressure at the surface is 760mm of mercury.
The density of mercury is 13.5
Please calculate the weight of the Earth's atmosphere and compare
answers
Nelson