View Single Post
Jan8-13, 07:05 PM
P: 4
Quote Quote by sophiecentaur View Post
Hanging a large mass on the end of the string will provide any tension you want. The string can obviously support it because that is the tension in normal operation. A mass (several kg) on a pulley is a lot cheaper than using any form of force meter for that sort of tension. It's a fairly common experiment. The way I have always excited the string has been to pass a current through the string and to put a fat magnet right next to it near an antinode. It achieves a very light coupling which doesn't affect the measurement.

As the formula involves three variables, you have to know two of them in order to calculate the third - (frequency).

You need to clamp the whole thing firmly or the mass will pull the whole thing over.
Thanks for the reply! I decided to do your idea with the pulley and as of right now, I have a plank of wood lying flat on a desk and a makeshift pole attatched to the plank. One end of the string is fastened securely onto the pole, and rather than using a pulley, could I just lay the string over another block of wood(where a weight will be attached to dangle over a desk)? Basically, must it be a pulley on the other end of the string? Or can it be substituted with another block of wood.

Then that way I could calculate the force of tension using fG=fT=ma?