1all will be correct...d option is correct
A man standing on a platform holds weights in his outstretched arms. The system is rotated about a central vertical axis. If the man now pulls the loads inwards close to his body, then :
A) angular vel. of the sys. will increase
B) angular momentum of the sys remains constant
C) K.E of the system is increased
d) all of the above
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9 Answers
1as the man pulls the weights towards him so mi of the system is decreasing so ang. vel should increase.and no ext. torque is there so ang. momentum is const.as k.e is dependant on ang.vel so ke should also increase.
23btw a doubt from my side ....who is doing work so that KE is increasing ?
23actually wat doubt i hav is that whether internal forces can cause change in KE of a system or not ......
so is this work done by man a work done by internal force or ........
24See man stands on axis..so no contribution of moi by him....so moi is only of loads...and so in system only thing is load..and man is external force whic hdoes work to change ke (rot) of load
19all of the above !
....the conservation of angular momentum says it all !
