physics problem

[zhul4nder]

A 160 pound weight that is 6 feet in length is supported by two poles, one on each end of the weight. One pole is raised 1 foot. Find the amount of addition weight applied to the opposite side when the other is raised 1 foot.

and uhh don't just give me the answer, show me how you did it >.<

this is not for homework or anything. I just wanted to try to figure out because i was doing pushups at the gym...and decided to raise my feet up. I wanted to know how much more weight is being added to my pushes when i add a certain amount of height.

-edit-
apparently this problem is actually extremely complicated involving torque, rotational momentum, etc...
all of which i have no idea how to use lol.

[devonin]

Re: physics problem

You also seem to not follow the forum rules for this kind of question.

[zhul4nder]

Re: physics problem

I drew a picture to help along with additional information


By zhul4nder

[foilman8805]

Re: physics problem

I looked at this last night, and it is a very complicated problem because your body can't be considered a point mass with gravity acting at the center.

Therefore, you're probably not going to find an answer to your question here. Sorry, man.

My best attempt at solving this problem for you is to ask you to bust out some scales and put them under your hands while you change your body position. This is an easy solution, and will get you pretty accurate results.

[zhul4nder]

Re: physics problem

*sigh* curse you physics, curse you!!

[QED Stepfiles]

Re: physics problem

This problem isn't actually that bad - there isn't any reason why you can't consider the body as a point mass with center of mass located approximately at the center. If we assume that the length of the body is sufficiently longer than the length of the height off the ground, then torque and angular considerations also become more or less negligible - the vast majority of the force exerted by the ground on the forearms would go into translation of the center of mass upwards.

In other words, this problem is easily approximated by a very simple situation of just the movement of a point mass upwards. Even if you wanted to take into account the rotational motion (and I don't know why you would, since in this situation it isn't really contributing much to the final results), then you can just as easily add that in by considering the center of mass motion and the motion ABOUT THE CENTER OF MASS separately.