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CGandC
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Homework Statement
The problem relates to the subject of torque and angular momentum:
A man of mass ## M ## stands on a railroad car that is rounding an unbanked turn of radius R at speed v.
His center of mass is height ## L ## above the car, and his feet are distance ## d ## apart.
The man is facing the direction of motion. How much weight is on each of his feet?
Answers:
Homework Equations
Torque and angular momentum equation.
Conservation of angular momentum.
Newton's second law.
The Attempt at a Solution
What they did is they calculated the torque with respect to the center of mass of the man ( this torque equals zero because he doesn't rotate with respect to his own center of mass ) . If I solve the problem this I get the right answer, but I don't want to do the problem this way, so I decided to calculate the torque with respect to the middle point ## \frac{d}{2} ## on the cart:
( the red cross in the picture below )
So, calculating the torque of the person with respect to the red-point I get that :
## -N_1*\frac{d}{2} +N_2*\frac{d}{2} = 0 ## ( equals to zero since the cart doesn't rotate with respect to itself )
Thereby , having : ## N_1 = N_2 ##
Which is the wrong answer.
( But the Newtons second law equations remain the same as in the answers, so the only problem is with the torque)
What I did wrong?