CADET CHALLENGE #3 HAS BEEN SOLVED!

Congratulations to Cadet LTJG Sara Rivera who solved cadet challenge #2.  The answer:  The minute hand would have to be 10 miles long (9.6 miles and change if you use the formula and a $200 calculator).  Here is an explanation:

• The end of the minute hand must travel 60 MPH.  Since it must make one circuit of the clock face in an hour (because it's a minute hand, Einsteins), the circumference of the clock must equal 60 miles (to travel 60 MPH, you must cover 60 miles in one hour).
• Knowing the circumference of the face, you can apply the formula for determining the circumference of a circle and solve algebraically for the radius--that's what Sara did.  Or, you can apply a little practical math.  Since you know that the circumference is 6 times the radius, you can work it backwards and, knowing that the radius is 60 miles, you can easily calculate that the radius (the length of the minute hand) is 10 miles.

For her efforts, Sara received a handsome, presentation quality MHS NJROTC pen.