Real-Life Math -- Solution
The doorway is able to hold 100 pounds per square inch. The top
of the doorway is 30 inches long by 3 inches wide.
30 inches x
3 inches = 90 square inches
90 x 100 pounds = 9,000 pounds
The
most weight this doorway can hold is 9,000 pounds. Based on your estimate
that the force on it will be about 4,100 pounds when the building is complete,
the doorway will easily withstand the pressure of a second floor.
Insurance
inspectors use math every day, says Catherine O'Neil, a consultant.
"We
have to figure out things like interior combustibility rates," she says. Math
also comes in handy for figuring out how much of a framework is masonry, when
measuring the distance between fire hydrants and a given structure and when
doing conversions.
Sound intimidating? "We do have calculators," she
laughs.