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Q: Measurement thru a microscope ( Answered 5 out of 5 stars,   0 Comments )
Subject: Measurement thru a microscope
Category: Science > Biology
Asked by: whitbyoz-ga
List Price: $15.00
Posted: 20 Oct 2004 03:10 PDT
Expires: 19 Nov 2004 02:10 PST
Question ID: 417439
Looking thru a microscope if there are x number of an an object seen
how do I calculate how many there would be per if the magnification
was 400 and the diameter 490 ? (The x nos. are 16 and 31)
Subject: Re: Measurement thru a microscope
Answered By: redhoss-ga on 20 Oct 2004 06:14 PDT
Rated:5 out of 5 stars
Hello whitbyoz, here is how I would solve your problem:

First convert the 490 micrometers into centimeters. To do this you
multiply micrometers by 1 x 10^-4 or 490 micrometers equals .049
centimeters. This is the diameter of your field of view.

Next calculate the area of your field of view using:

Area = pi d^2 / 4 

Area = 3.1416 (.049)^2 / 4 = .0018857 cm^2

Then your formula becomes:

Number per = X / .0018857 

For X = 16

Number per = 16 / .0018857 = 8,485

For X = 31

Number per = 31 / .0018857 = 16,439

If there is any of this you don't understand, please ask and I will try and help.
whitbyoz-ga rated this answer:5 out of 5 stars
Easy to follow and an answer that made sense. Many Thanks

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