Real-Life Math
Aerospace engineers use math all the time. For example,
aerodynamicists calculate the loads (forces) upon a plane using wind tunnels
and computer calculations. The designers then do preliminary calculations
to determine whether the parts they've designed can withstand the loads that
will be placed upon them.
They don't have to absolutely confirm that
a part can withstand a certain load -- that's up to the stress department.
The stress analysts use a computer program called finite element analysis
to determine whether a part is strong enough -- or too strong!
You're
designing a support rod for the inside of an aircraft wing. Your current design
specifications call for the rod to be made out of aluminum and to have a diameter
of 20 millimeters. (Note that in this field, you will be using the metric
system of measurements!)
It will be supporting a load of 50 x 103
newtons (N), a measurement of force. According to your stress analysis tables,
the allowable stress on aluminum is 100 x 106Pa. A Pa is a Pascal,
which is: N / m2.
You know that the formula for stress on
a rod is:
Stress = load / area
Area =
pi r2
pi = 3.14
r = radius, in meters
Determine
the stress on the rod. Can you use an aluminum rod? Is it within the allowable
stress for aluminum?