- #1
Checkfate
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Okay, I need help with this question. It is killing me!
A circular drum is spinning round and round. A person is on the wall of the drum and there is no floor beneath him. If the drum has a radius of 2.4m and takes 2.5s to comlete a revoltion, what is the coefficient of friction reqired to prevent him from falling out?
I calculated the speed of the drum.
(Pi symbol did not work... PI=pi)
[tex] v=\frac{2PIr}{T}[/tex]
[tex]=6.0m/s[/tex]
and then used that to calculate the centripetal acceleration.
[tex] a_{c}=\frac{v^{2}}{r} [/tex]
[tex]=\frac{36m^{2}/s^{2}}{2.4m}[/tex]
[tex]=15m/s^{2}[/tex]
But then I haven't the slightest clue how to calculate a coefficient of friction. I thought that perhaps I could treat the drum as a planet and it's gravitational constant could be the centripetal acceleration (I am guessing this is the right line of thinking :) ) but then the fact that I lack a mass to work with gets in the way. Can someone point me in the right direction? Thanks
coefficient of friction = [tex]\frac {F_{f}}{F_{N}} [/tex] but I can't calculate forces without a mass!
A circular drum is spinning round and round. A person is on the wall of the drum and there is no floor beneath him. If the drum has a radius of 2.4m and takes 2.5s to comlete a revoltion, what is the coefficient of friction reqired to prevent him from falling out?
I calculated the speed of the drum.
(Pi symbol did not work... PI=pi)
[tex] v=\frac{2PIr}{T}[/tex]
[tex]=6.0m/s[/tex]
and then used that to calculate the centripetal acceleration.
[tex] a_{c}=\frac{v^{2}}{r} [/tex]
[tex]=\frac{36m^{2}/s^{2}}{2.4m}[/tex]
[tex]=15m/s^{2}[/tex]
But then I haven't the slightest clue how to calculate a coefficient of friction. I thought that perhaps I could treat the drum as a planet and it's gravitational constant could be the centripetal acceleration (I am guessing this is the right line of thinking :) ) but then the fact that I lack a mass to work with gets in the way. Can someone point me in the right direction? Thanks
coefficient of friction = [tex]\frac {F_{f}}{F_{N}} [/tex] but I can't calculate forces without a mass!
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