Negative Exponents

Date: 8/27/95 at 8:28:52
From: Stephen Nolte
Subject: Re: Steve needs help

Hi Dr. Math,

Here is the problem:

   1 Joule = 1kg m 2/s -2

The 2 and -2 are powers, not whole numbers in this equation.
I am not sure how to put it this way on the computer.

In this equation, what does the negative power of 2 mean?  How is 
this operation done?  Thanks! 

Steve Nolte

Date: 8/27/95 at 15:18:30
From: Doctor Ken
Subject: Re: Steve needs help

Hello!

The normal way people type exponents in situations like this is to use the
upper caret symbol, like this: x^2.  

Negative exponents mean that instead of multiplying that many of the base
together, you divide.  For instance, 3^2 = 9, and 3^-2 = 1/9.  That's one
way to see why anything to the zero power (except perhaps 0) is 1.  The
way most people think of negative exponents is "put it in the bottom of the
fraction."

A Joule is a kilogram meter squared per second squared.  That translates
to either 1 kg m^2 s^-2 or 1 kg m^2/s^2.  

-Doctor Ken,  The Geometry Forum