 #1
Plutonium88
 174
 0
Ball Rolls off of a circle :O! PROBLEM!
So the problem is, a ball at zero velocity begins to roll on a circle. At a certain point the ball and the circle "DISCONNECT". There is a height x from the roof to the point it disconnects.
Given Information. Height X, Diameter D of circle, Vi=0, r=1/2D Mo=Mass Of The ball
http://postimage.org/image/a91pl12ll/
Relative Equations:
Conservation Of Energy
Maybe centripetal force formula (Fc=Fg,ffr,)

My attempt:
i believe that at the point the ball ejects from the surface of the big circle, that the FN = 0 because it isn't going to be connected anymore... (CORRECT ME IF I'M WRONG)
 I feel like i don't have enough information, (obviously i do) but maybe i do not have the skills... I was wondering if some one could lead me in the right direction...
Now ET1=energy of the system at the top at rest
ET2=energy of the system at the point it detaches...
Et1=Et2
mgD=mgDmgX+1/2mov2^2 simplify
X = V2^2/2g
Now obviously I'm left with a problem with two unknowns... I've been drawing triangles all over this circle and trying to figure out how i can get an angle.. I figured out it makes an isosceles triangle if you connect the radius twice to the the point at which it detaches... But still i don't know how to get an angle.. I think i need to learn radiants(Or would that even help me)?
Anyways I'm stuck just need a little hint, please don't answer the whole problem
So the problem is, a ball at zero velocity begins to roll on a circle. At a certain point the ball and the circle "DISCONNECT". There is a height x from the roof to the point it disconnects.
Given Information. Height X, Diameter D of circle, Vi=0, r=1/2D Mo=Mass Of The ball
http://postimage.org/image/a91pl12ll/
Relative Equations:
Conservation Of Energy
Maybe centripetal force formula (Fc=Fg,ffr,)

My attempt:
i believe that at the point the ball ejects from the surface of the big circle, that the FN = 0 because it isn't going to be connected anymore... (CORRECT ME IF I'M WRONG)
 I feel like i don't have enough information, (obviously i do) but maybe i do not have the skills... I was wondering if some one could lead me in the right direction...
Now ET1=energy of the system at the top at rest
ET2=energy of the system at the point it detaches...
Et1=Et2
mgD=mgDmgX+1/2mov2^2 simplify
X = V2^2/2g
Now obviously I'm left with a problem with two unknowns... I've been drawing triangles all over this circle and trying to figure out how i can get an angle.. I figured out it makes an isosceles triangle if you connect the radius twice to the the point at which it detaches... But still i don't know how to get an angle.. I think i need to learn radiants(Or would that even help me)?
Anyways I'm stuck just need a little hint, please don't answer the whole problem
Last edited: