September 29, 2008
From Greg Mankiw‘s blog:
From a freshman physics quiz given at Princeton a few days ago:
Problem 1. A famous thought experiment in economics involves dealing with a financial crisis by dropping money from a helicopter.
Ben Bernanke, Federal Reserve Chairman and former Princeton Economics Professor, decides to try this out over his old hometown. With his helicopter flying 1.0Ã—10^1 m above the center of Fine Tower and in the direction of Nassau Hall, Ben gently releases a briefcase containing $1 million. Using the information that (i) Fine Tower is 6.0 Ã— 10^1 m high, (ii) Nassau Hall is 1.5 Ã— 10^1 m high and (iii) the centers of the two buildings are 3.0 Ã— 10^2 m apart, and ignoring air resistance as you normally would:
a. [2 pts] How fast should Ben’s helicopter fly so that the briefcase lands in the center of the roof of Nassau Hall?
b. [1 pt] How long is the briefcase in the air?
c. [1 pt] How fast is the briefcase moving when it hits the roof of Nassau Hall?
d. [1 pt] How much faster would the financial relief have reached Nassau Hall if the briefcase had contained $2 million instead?
Thanks to Princeton Professor Shivaji Sondhi for sending this along.
Greg is an economics professor at Harvard.
Date: September 29th, 2008 dw