Suppose you were planning to move a house by tansporting it on a large trailer. The house has an estimated wight of
tons (
). The trailer is expected to weigh
tons. Each wheel of the trailer will have tires inflated to a gauge pressure of
psi (which is actually
psi above atmospheric pressure). If the area of contact between a tire and the pavement can be no larger than
(
), what is the minimum number of wheels the trailer must have? (Remember, tires are mounted in multiples of two on a trailer. Assume that atmospheric pressure is
psi).
(Brady, 430/10/83)