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tnhoots
Feb15-07, 12:23 PM
1. The problem statement, all variables and given/known data

A 4.95 kg object is attached to a vertical rod by two strings. The object rotates in a horizontal circle at constant speed 7.25 m/s. the lenght of both strings is 2.00m and the lenght of the verticle rod is 3.00m.

(a) Find the tension in the upper string.
N
(b) Find the tension in the lower string.
N



2. Relevant equations

equation for radius: r^2=c^2 - b^2

3. The attempt at a solution

radius equals 1.32m

JK423
Feb15-07, 12:25 PM
If i could have a picture of the set or something..

tnhoots
Feb15-07, 06:26 PM
I could not copy and past the pic...it wouldn't let me paste it on here. It's pretty much a verticle rod with a string coming from the top and the bottom corners to form a triangle. That's the best way I know how to depict it. Sorry

danago
Feb15-07, 06:30 PM
I could not copy and past the pic...it wouldn't let me paste it on here. It's pretty much a verticle rod with a string coming from the top and the bottom corners to form a triangle. That's the best way I know how to depict it. Sorry

You can upload the image by going to http://imageshack.us, and clicking "Browse". Then just locate the image on your hard drive and press upload. Use the link you are given to show the picture.

tnhoots
Feb15-07, 06:36 PM
Thanks for the help about uploading the image....here it is.


http://img165.imageshack.us/img165/7128/p611dh0.gif (http://imageshack.us)

tnhoots
Feb15-07, 06:37 PM
Hope this helps us all out...I know I need it!

turdferguson
Feb15-07, 07:09 PM
What is the centripetal force?

tnhoots
Feb15-07, 09:10 PM
the cent. acceleration is v^2/r. Which is 19.6^2/10=38.416

Pyrrhus
Feb15-07, 11:33 PM
The problem is pretty straight forward. The acceleration only has one component which is the radial one, so the speed is constant. Use trigonometry to find the radius and to set the component of the tension in the direction of the radial acceleration.