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JDK1.0.2 simulations (1996-2001) => Dynamics => Topic started by: Khaldoun-Habboub on February 20, 2006, 06:02:14 pm

 Title: Centre of Gravity problem Post by: Khaldoun-Habboub on February 20, 2006, 06:02:14 pm Hey,If a uniform metre rule has a 4N weight hanging from one end, and the rule balances when suspended from a point 0.1m from that end. What would be the weight of the rule??? cheers Title: topic338 Post by: Fu-Kwun Hwang on February 21, 2006, 10:27:28 am May be I did not fully understand your question.But why the weight of the rule will be changed when suspended from different points? Title: Strange ha!! Post by: Khaldoun-Habboub on February 22, 2006, 04:17:45 pm You are absolutely right, but the question was stated exactly the same way I stated above.It came from a physics text book by Oxford. :!: Title: topic338 Post by: hy2220N11411E on March 23, 2006, 12:45:26 am The orginal question should be interpreted this way:a uniform metre rule (or ruler) means a beam of 1 metre in length;a 4N weight (a separated heavy object) being hanged from one end, exerting a downward force;the rule is being hanged 0.1m from the end with the 4N weight, exerting an upward force (the tension);uniform metre rule means the CG (centre of gravity) is 0.5m from either end, and the weight of the rule is producing another downward force;Let W = weight of the rule, T = the tension to "hang" the ruletaking moment about the end with the "4N weight", then(0.1)(T) = (0.5)(W)all upward forces = all downward forces, thenT = W + 4by solving the simultaneous equationsW = 1so the weight of the rule is 1 N Hope my words help.Cheers. Title: Re: Centre of Gravity problem Post by: bluebearqq on February 20, 2011, 05:56:51 am  :)