The US quarter has a mass of 5.67 g and is approximately 1.55 mm thick.
(a) How many quarters would have to be stacked to reach 575 ft, the height of the Washington Monument?
(b) How much would this stack weigh?
(c) How much money would this stack contain?
(d) The US National Debt Clock showed the outstanding public debt to be $11,687,233,914,811.11 on August 19, 2009. How many stacks like the one described would be necessary to pay off this debt?