- #1
sona1177
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A 2.0 kg, uniform, horizontal rod has a point .25 m from the left and .75 from the right. Find the gravitational torque about this point.
I'm confused I'm getting -6.7 because grav torque =mgd so for the the portion to the left of the point has a center of gravity of .125 m and to the right has .25 m. So the mass towards the left is .5 kg and mass towards the right is 1.5 kg. That means torque for the left portion is .5 *.125 * 9.8=.6125 and for the right is 1.5*9.8 * .5=7.35. So since .6125 - 7.35 = -6.7 N-m. The answer is -2.1 Nm what am I doing wrong?
I'm confused I'm getting -6.7 because grav torque =mgd so for the the portion to the left of the point has a center of gravity of .125 m and to the right has .25 m. So the mass towards the left is .5 kg and mass towards the right is 1.5 kg. That means torque for the left portion is .5 *.125 * 9.8=.6125 and for the right is 1.5*9.8 * .5=7.35. So since .6125 - 7.35 = -6.7 N-m. The answer is -2.1 Nm what am I doing wrong?