To: Teacher2Teacher Public Discussion
Subject: Re: Volume formula for a sphere
Here is a volume problem for students. Best to allow using a calculator. How many cubic centimeters would the universe be if the universe is 8 billion light years across and is shaped like a sphere? To start, the radius is 4 billion light years. Light travels at a rate of 186000 miles per second. In one year light travels 186000x60x60x24x365.25 miles= 5.8697136x10^12 miles. (Multiply by 4 billion and we get: 2.34788544x10^22 milles. Now we will convert to feet then inches and then centimeters: 2.348849664x10^22 x 5380 x 12 x 2.54 = 3.778555346x10^27 centimeters. Now we can find the volume: V=(4/3)xpixradius cubed: = 4/3 x pi x radius^3= 2.259779022x10^83 cubic centimeters. Now that is less then the number of chedder man's possible desecendents if one considers that chedder's descendents are only related to him in one way. Search for chedder to find a problem posted on this site 6 July 2003 under the title of Math gimmicks. In that problem we found the number of descendents would be 2 x 10^90 or there abouts. Much bigger than our 2.3 x x 10^83. Of course anyone related to Chedder has to be related to him in many many ways something like the old song, I am my old grandpa. Notes: 60 seconds in one minute. 60 minutes in hour 24 hours in one day 365.4 days in one year 5280 feet in one mile 12 inches in one foot 2.54 centimeters in one inch.
Math Forum Home || The Math Library || Quick Reference || Math Forum Search