- #1
Shing
- 144
- 1
Today, in my school's physics lab lecture, we were doing an experiment for Standing wave. And
I found a strange phenomenon:
If I made the distance between tonometer and the pulley long eough, there won't be any observed standing wave! I have no idea the reason. First, I thought: um... because the tension will larger when the length larger? then I find the tension will always be mg! (is it true?)
Then I have thought up a few reason, no idea how to find out whether they are right or not.
1.) because there is elasticity for the rope, the longer the length is, the more it adsorbs. (but how to disprove that if it is wrong? and how could all the vibration , say out of the blue, disappear to a degree that we can't observe the vibration ?)
2.) vibration will make the tension not a constant neither parallel to the table, and the
tension canceled the movement (but that can't explain why when it was short enough, we did observe the standing wave.)
would anyone be kind enough to give me a few hints or keys?
So I have no idea the reason. Sorry for the poor writing (english is my second language)and manner of asking. Thanks for reading =)
I found a strange phenomenon:
If I made the distance between tonometer and the pulley long eough, there won't be any observed standing wave! I have no idea the reason. First, I thought: um... because the tension will larger when the length larger? then I find the tension will always be mg! (is it true?)
Then I have thought up a few reason, no idea how to find out whether they are right or not.
1.) because there is elasticity for the rope, the longer the length is, the more it adsorbs. (but how to disprove that if it is wrong? and how could all the vibration , say out of the blue, disappear to a degree that we can't observe the vibration ?)
2.) vibration will make the tension not a constant neither parallel to the table, and the
tension canceled the movement (but that can't explain why when it was short enough, we did observe the standing wave.)
would anyone be kind enough to give me a few hints or keys?
So I have no idea the reason. Sorry for the poor writing (english is my second language)and manner of asking. Thanks for reading =)