In 1656, the Burgmeister (mayor) of the town of Magdeburg, Germany, Otto Von Gue
ID: 2224678 • Letter: I
Question
In 1656, the Burgmeister (mayor) of the town of Magdeburg, Germany, Otto Von Guericke, carried out a dramatic demonstration of the effect resulting from evacuating air from a container. It is the basis for this problem. Two steel hemispheres of radius 0.420 m (1.38 feet) with a rubber seal in between are placed together and air pumped out so that the pressure inside is 15.00 millibar. The atmospheric pressure outside is 970 millibar. Calculate the force required to pull the two hemispheres apart.[Note: 1 millibar=100 N/m2. One atmosphere is 1013 millibar = 1.013
Explanation / Answer
Force=AP=*0.422*(0.97-0.015)*105=52924N(here A is the projected area)
No.of horses required=2*52924/1450=74 horses