What are the tensions in the strings for a rotating object?

[tnhoots]

More tension prolbmes!

Homework Statement

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 length of both strings is 2.00m and the length 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

Homework Equations

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

The Attempt at a Solution

radius equals 1.32m

 

[JK423]

If i could have a picture of the set or something..

 

[tnhoots]

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]

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]

Thanks for the help about uploading the image...here it is.


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

 

[tnhoots]

Hope this helps us all out...I know I need it!

 

[turdferguson]

What is the centripetal force?

 

[tnhoots]

the cent. acceleration is v^2/r. Which is 19.6^2/10=38.416

 

[Pyrrhus]

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.