The U.S. 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 29, 2009. How many stacks like
the one described would be necessary to pay off this debt?

## Answer

Convert the height of a quarter in terms of inches from millimeter as follows 1 in 25.4 mm in 1.55 mm = 1.55 prfx 25.4 am 1.55 25.4 Now, convert the thickness of quarter in terms of ft as follows 1ft=12 in 1.55.1.55 1 ft 254 25412 jn 0.0051 ft

Then the number of quarters required to reach 575 ft is as follows: Number of quarters 0.0051 f =1.13×105 Hence, the number of U.S. quarters required is. 1.13×10 To find the weight of quarter multiply the number of quarters required with the mass of one quarter as follows: Weight of stack – 1.13×10 quarters x 5.67 g -6.41×10 g Hence, the weight of quarters in 6.41 10 The value of one quarteris 0.25 Number of quarters is 1.13×10 Then the total money in the stack is as follows: Total money-1.13×10 x $ 0.25 -$ 2.83×10 Hence. the total money in the stack is $ 2.83x 10

Total money which has to be pay off the debt is $ 16,213,166,914,811 Total money in a stack is S 2.83×101. Then the number of stacks required is as follows: Number of stacks- $ 2.83×10 -5.74×10 Hence, the number of stacks required is 5.74×10