- #1
govinda
- 13
- 0
theres a standard question about the spinning dancer who pulls her hands inward reducing her moment of inertia and increasing her ang. velocity . it seems she had to do some work against the centrifugal force (from momentum and energy equations)
i thought of a simpler example to check if the amt of work that needs to be done agianst the force is indeed equal to the change in energy .considering a particle insted of the ballerina moving in a circle i worked out the work necassary using integral of force times distance moved . i substiuted values for ang. vel. since it isn't constant(from cons of ang momentum eq.) and it worked out to be a logarthmic expression . the change in energy from the first approach was different( no log term) . i have a feeling i have made some fundamental mistake . the calculations seem ok.,
govinda
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"if its you against the world bet on the world "
i thought of a simpler example to check if the amt of work that needs to be done agianst the force is indeed equal to the change in energy .considering a particle insted of the ballerina moving in a circle i worked out the work necassary using integral of force times distance moved . i substiuted values for ang. vel. since it isn't constant(from cons of ang momentum eq.) and it worked out to be a logarthmic expression . the change in energy from the first approach was different( no log term) . i have a feeling i have made some fundamental mistake . the calculations seem ok.,
govinda
--------------------------------------------------
"if its you against the world bet on the world "