High sided trucks are very vulnerable to cross winds on freeways. Consider a truck with a total weight of 1.5 x 10^5 Newtons, a length 15m, width 2m, and with sides of height 8m. Assume the pressure exerted by wind at speed v, hitting a vertical surface normally is pv^2, where p is the density of air (=1.2kg.m^-3).
(a) Calculate the force exerted on one side by a cross wind of speed 15m/s^-1.
(b) Assume that the wind force, F, exerts a turning moment about one side equal to Fh/2, where h is the height of the side. Is the wind force calculated in (a) strong enough to lift one side?
(c) Even if the wind force did not lift one side, what might be the result of the wheel grip on the road differing on each side?
1. Calculate the force exerted on one side by a cross wind of speed 15ms-¹.
The press is: P=pv^2=1.2*15^2=270 Pa
To calculate the force exerted on one side, ...
This solution includes calculations and answers from (a) through (c).