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A bob of mass m attached to an inextensible string of length l is suspended from a vertical support. The bob rotates in a horizontal circle withan angular speed omega rad/s about the vertical support. About the point of suspension

Answer» <html><body><p><a href="https://interviewquestions.tuteehub.com/tag/angular-11524" style="font-weight:bold;" target="_blank" title="Click to know more about ANGULAR">ANGULAR</a> momentum is conserved<br/>angular momentum changes in magnitude but not in direction<br/>angular momentum changes in direction but not in magnitude <br/>angular momentum changes both in direction and magnitude</p>Solution :Magnitude of radius vector `vec(r )= |vec(r )|= l`constant. <br/> Magnitude of the momentum `vec(p)` of the bob <br/> = `|vec(p)|`= mv = m`omega l` = constant <br/> As angular momentum `vec(L) = vec(r ) xx vec(p)` and the angle between `vec(r ) and vec(p)` is <a href="https://interviewquestions.tuteehub.com/tag/always-373607" style="font-weight:bold;" target="_blank" title="Click to know more about ALWAYS">ALWAYS</a> `90^(@)`. <br/> `|vec(L)| = l cdot m omega l cdot sin 90^(@) = m l^(2) omega` = constant <br/> <a href="https://interviewquestions.tuteehub.com/tag/also-373387" style="font-weight:bold;" target="_blank" title="Click to know more about ALSO">ALSO</a>, `vec(r)` is l aways radially outwards and `vec(p)` is <a href="https://interviewquestions.tuteehub.com/tag/tangential-1239000" style="font-weight:bold;" target="_blank" title="Click to know more about TANGENTIAL">TANGENTIAL</a>. So `vec(L)` is always <a href="https://interviewquestions.tuteehub.com/tag/directed-440230" style="font-weight:bold;" target="_blank" title="Click to know more about DIRECTED">DIRECTED</a> along the axis of rotation. So its direction is also fixed.</body></html>


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