One of the dangers of tornados and hurricanes is the rapid drop in air pressure that is associated with such storms. Assume that the air pressure inside of a sealed house is 1.02 atm when a hurricane hits. The hurricane rapidly decreases the external air pressure to 0.910 atm. What net outward force is exerted on a square window of the house that is $2.03 \mathrm {~m}$ on each side? (1.00 atm = 1.01 × 10⁵ Pa) A) 4.59 × 10⁴ N B) 5.19 × 10⁴ N C) 4.82 × 10⁵ N D) 5.42 × 10⁵ N

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Quizplus · Accepted Answer

The net outward force is the difference between the inward force due to the air pressure inside the house and the outward force due to the air pressure outside the house. The inward force is:$$F_{in} = P_{in}A = (1.02 \mathrm{~atm})(1.01 	imes 10^5 \mathrm{~Pa})(2.03 \mathrm{~m})^2 = 4.21 	imes 10^5 \mathrm{~N}$$The outward force is:$$F_{out} = P_{out}A = (0.910 \mathrm{~atm})(1.01 	imes 10^5 \mathrm{~Pa})(2.03 \mathrm{~m})^2 = 3.75 	imes 10^5 \mathrm{~N}$$The net outward force is:$$F_{net} = F_{out} - F_{in} = 3.75 	imes 10^5 \mathrm{~N} - 4.21 	imes 10^5 \mathrm{~N} = -4.59 	imes 10^4 \mathrm{~N}$$The negative sign indicates that the net force is inward, which is what we would expect since the air pressure outside the house is lower than the air pressure inside the house.

One of the Dangers of Tornados and Hurricanes Is the Rapid