- #1
Dell
- 590
- 0
in the following question,
http://62.90.118.184/Index.asp?CategoryID=318
i am given the following only:
angle of the cord = [tex]\alpha[/tex]
angular velocity = [tex]\omega[/tex]
and am asked to find the radius
what i did was :
Newtons 2nd on the radial and "y" axis
Fy=T*cos([tex]\alpha[/tex])-mg=0 (T being tension in the cord)
T=mg/cos([tex]\alpha[/tex])
Fr = T*sin([tex]\alpha[/tex]) = mar =m[tex]\omega[/tex]2R
T*sin([tex]\alpha[/tex]) =m[tex]\omega[/tex]2R
now i use the T i found (T=mg/cos([tex]\alpha[/tex])) and i get
mg*tg([tex]\alpha[/tex])=m[tex]\omega[/tex]2R
R=g*tg([tex]\alpha[/tex])/[tex]\omega[/tex]2
which according to the answer sheet is the correct answer, but i cannot understand how the radius does not depend on the length of the cord or the length of the top, horizontal bar??
http://62.90.118.184/Index.asp?CategoryID=318
i am given the following only:
angle of the cord = [tex]\alpha[/tex]
angular velocity = [tex]\omega[/tex]
and am asked to find the radius
what i did was :
Newtons 2nd on the radial and "y" axis
Fy=T*cos([tex]\alpha[/tex])-mg=0 (T being tension in the cord)
T=mg/cos([tex]\alpha[/tex])
Fr = T*sin([tex]\alpha[/tex]) = mar =m[tex]\omega[/tex]2R
T*sin([tex]\alpha[/tex]) =m[tex]\omega[/tex]2R
now i use the T i found (T=mg/cos([tex]\alpha[/tex])) and i get
mg*tg([tex]\alpha[/tex])=m[tex]\omega[/tex]2R
R=g*tg([tex]\alpha[/tex])/[tex]\omega[/tex]2
which according to the answer sheet is the correct answer, but i cannot understand how the radius does not depend on the length of the cord or the length of the top, horizontal bar??