Mass on table connected to hanging mass by string through hole

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Homework Statement


Diagram of a mass m on a frictionless table moving in a circle of radius L, connected by a string through a hole to a hanging mass M; the table rotates at f rev/sec.


Homework Equations


E=T+U
T=1/2 mv^2
U=∫F⋅dr

The Attempt at a Solution



Part 1 Work
x=x-dot
y=y-dot
z= z-dot
r=r-dot
θ=θ-dot
[/B]
T= 0.5m(x^2 +y^2) 0.5M(z)^2
Changing to polar coordinates
T=0.5m(r^2 +rθ^2) 0.5M(z)^2

U=-Mgz

E=T+U
=0.5m(r^2 +rθ^2) 0.5M(z)^2-Mgz

z=L-r

= 0.5m(r^2 +rθ^2) 0.5M(z)^2-Mg(l-r)


I drew the FBD for both:
for mass on table
Free-body diagram of mass m with four labeled forces: Fn=normal force upward, Fg=mg downward, T=tension leftward, and Fc pointing rightward.

Fx
Fc-T=ma

Fc= mrw^2
T=Mg
mrw^2-Mg=ma

a=
rw^2-(Mg)/m
v=rw^2-(Mg)r/m

for hanging mass
Free-body diagram of a hanging mass: a vertical line with a small circle at its midpoint, labelled Fc at the top end and Fg=mg at the bottom end.


Fc-Fg=0
Fc=Fg
Fc=Mg

No acceleration or velocity

Is this the right track
 
Attachments
  • Diagram of a mass m on a horizontal table moving in a dashed circle, tied by a string of length L through a hole in the table to a hanging mass M; the frev/sec label marks the rotation.
    upload_2018-10-28_8-21-33.png
    11.7 KB · Views: 435
  • Diagram of a mass m on a frictionless table moving in a circle of radius L, connected by a string through a hole to a hanging mass M; the table rotates at f rev/sec.
    upload_2018-10-28_8-22-37.png
    11.1 KB · Views: 808
  • Free-body diagram of mass m with four labeled forces: Fn=normal force upward, Fg=mg downward, T=tension leftward, and Fc pointing rightward.
    upload_2018-10-28_8-34-28.png
    2 KB · Views: 395
  • Free-body diagram of a hanging mass: a vertical line with a small circle at its midpoint, labelled Fc at the top end and Fg=mg at the bottom end.
    upload_2018-10-28_8-44-39.png
    934 bytes · Views: 342
  • Free-body diagram of a small circle on a vertical line, with an upward arrow labelled Fc at the top and a downward label Fg=mg at the bottom.
    upload_2018-10-28_8-46-17.png
    934 bytes · Views: 427
Last edited:
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