1. Obtain a measurement. First, get a measurement in tenths of a second. It doesn't matter how long or short  it can be 1/10 or 100/10; it's all a matter of rearranging the fraction
http://www.ehow.com/how_8390837_converttenthssec...

Anytime you have a number divided into "TENTHS" the answer is 10!
http://wiki.answers.com/Q/How_many_tenths_of_a_sec...

I figure it takes one tenth of one tenth of a second for a bullet to cross the space
http://www.chacha.com/question/howfastisatenth...

For 15 seconds, therefore the second hand is already in 90 degrees position. arc measure = 2 cm. arc measure =angle/360) x (2 times pi times radius) 2cm = (90/360) x (2 x pi x radius
http://answers.yahoo.com/question/index?qid=201310...
