Posted by Anonymous on Monday, March 29, 2010 at 9:50am.
Suppose a 69 kg person stands at the edge of a 7.8 m diameter merrygoround turntable that is mounted on frictionless bearings and has a moment of inertia of 1600 kg*m^2. The turntable is at rest initially, but when the person begins running at a speed of 3.7 m/s (with respect to the turntable) around its edge, the turntable begins to rotate in the opposite direction. Calculate the angular velocity of the turntable. Please help with stepbystep explanation.

college physics  drwls, Monday, March 29, 2010 at 10:41am
The total angular momentum remains zero because of the frictionless bearings. The person and the turntable rotate about the axis of rotation in opposite directions.
Let w be the angular velocity of the turntable after "the person" begins running. His (or her) angular momentum about the axis is
M V R = M (3.7  R w) *R
Note that we have to use the speed V with respect to land, not the turntable. That is why R w has to be subtracted from the velocity with respect to the turntable.
Solve this equation for the angular velocity w:
I w = M (3.7  R w) *R
I w (1 + MR^2)= 3.7 M R
Answer This Question
Related Questions
 physics  Suppose a 69 kg person stands at the edge of a 7.8 m diameter merrygo...
 Physics  A 3.6 diameter merrygoround is rotating freely with an angular ...
 Physics  A turntable with a moment of inertia of 0.017 kg*m^2 rotates feely at ...
 Physics  A turntable of radius 2m rotates freely about a fixed vertical axis. A...
 Physics  A woman with mass of 57 kg stands at the rim of a horizontal table ...
 physics  A woman with mass of 63 kg stands at the rim of a horizontal table ...
 physics  a turntable rotates about a fixed axis, making one revolution in 10s...
 Physics  A turntable with a moment of inertia of 0.017 kg*m^2 rotates feely at ...
 Physics  A turntable with a moment of inertia of 0.029 kg*m^2 rotates feely at ...
 physics  A turntable with a moment of inertia of 0.014 kg*m2 rotates feely at ...
More Related Questions