circular motion q (1 Viewer)

[totallybord]

hi,
somebody who can explain this q to me, help me plz
2 light strings AB n BC each lengh c are joined at B.
partilces mass m r each attched at B n C
the end of A of AB is fixed n the system rotates with a constant angular velocity abt the vertical line through A, the strings being in the same vertical plane through A at any instant
if AB n BC makes angles of alpha n beta resp. with the vertical measured in the same drection prove that.
2tan(alpha)/tanbeta = [2sinalpha +sinbeta] / {sinalpha +sinbeta}
can u draw the diagram n explain the q?
btw, what does direection of motion mean at P or any pt in projectile motion'?
thankss

 

[Js^-1]

...Uh, the question isn't very well explained, but I will give it a shot.

This is my intepretation...

The two green dots are moving in circular motion, since they are always in the same vertical plan, and the particle at B is moving in circular motion. The angles are as given, and the lengths of the strings AB and BC are each of length c.

As to the question, I'm not quite sure. I'll give it a crack sometime later today when i get some more time.

The direction of motion of a particle P moving in constant angular velocity is tangential to the path of the motion.

 

[vds700]

heres my soution, quite long, hope u can follow

 

[Js^-1]

Nice...I sound like a bit of a noob, but how do you get the attachments to be bigger? Mine won't let me upload it if its over about 96KB

 

[totallybord]

thanks vds700 again!
i get it but can you explain the whole forces thing to me like i know what it is
but why did u have a T2sinbeta for radially? i thought it wld hae been jst T1sinalpha = mrw^2 ...sorry im a non-physics person n dont get this whole tension thingy
say u have 3 masses, and AE is a vertical line, theres a string on A and on that string is a mass m, called C, and the string is threaded through a ring B, that passes out and theres a mass at the end called D all mass m, how wld u resolve the tensions?

 

[vds700]

thanks vds700 again!
i get it but can you explain the whole forces thing to me like i know what it is
but why did u have a T2sinbeta for radially? i thought it wld hae been jst T1sinalpha = mrw^2 ...sorry im a non-physics person n dont get this whole tension thingy
say u have 3 masses, and AE is a vertical line, theres a string on A and on that string is a mass m, called C, and the string is threaded through a ring B, that passes out and theres a mass at the end called D all mass m, how wld u resolve the tensions?

Basically, the radial components of the 2 tension forces, T₁ and T₂ provide the inwards force for the particles to move in circular motion (For particles to move in a circle, there must be a force directed towards the centre of the circle). Its a bit confusing with B, because it is affected by T₁ and T₂, T₂ acting downwards trowards C. Only T₂ acts on C, but is directed upwards towards B.

The vertical components balance the weight forces of the 2 particles, so there is no vertical movement

Nice...I sound like a bit of a noob, but how do you get the attachments to be bigger? Mine won't let me upload it if its over about 96KB

I save it in pdf form and its a bigger limit

 

[Js^-1]

Ah of course, thanks for that.