# Money Explained

## Recommended Posts

"c is always constant"' date=' because that's an [b']axiomatic[/b] rebuttal. The thrust of the argument against this essay is "c cannot be variable because c is constant, QED"

You know, the biggest irony in his use of QED is that QED means Quod Erat Demonstratum, which literally translates into because it was demonstrated.

Well, I think that wraps these threads up. I think they should be moved to the trash can; they aren't really all that great and there is nothing more to say in them.

##### Share on other sites

Hold this piano stationary for eight hours. I'll pay you according to how much physics work is done. Interested in the job?

In what position do you want it held?

I'd find higher than six feet from the floor to be a problem.

And what would you want it to be stationary in relation to, the floor, or the fly?

##### Share on other sites

In what position do you want it held?

I'd find higher than six feet from the floor to be a problem.

And what would you want it to be stationary in relation to, the floor, or the fly?

Ideally, stationary with respect to the floor, with arms perpendicular to the body. But really, if you're going to personally hold a piano stationary for eight hours, it won't matter what position you use; from a physical statndpoint I don't think anyone can do it, and (more importantly) there's no work done, which is why others have offered a multiple of what I would pay.

##### Share on other sites

Ideally, stationary with respect to the floor, with arms perpendicular to the body. But really, if you're going to personally hold a piano stationary for eight hours, it won't matter what position you use; from a physical statndpoint I don't think anyone can do it, and (more importantly) there's no work done, which is why others have offered a multiple of what I would pay.

Do my perpendicular arms rest on the piano, or does the piano rest on my outstretched arms? If the latter, a considerable amount of work would be involved. I'm very strong.

##### Share on other sites

Do my perpendicular arms rest on the piano, or does the piano rest on my outstretched arms? If the latter, a considerable amount of work would be involved. I'm very strong.

if you hold it stationary then there is absolutely NO work done no matter how you hold it.

Work = Force times Distance.

since its stationary, Distance = 0 m, therefore Work = 0 J

##### Share on other sites

if you hold it stationary then there is absolutely NO work done no matter how you hold it.

Work = Force times Distance.

since its stationary, Distance = 0 m, therefore Work = 0 J

To hold something up in that position requires a constant pushing upwards. An upward force does not involve movement if the force upward equals the force downward due to gravity. However an equal force exerted on the piano in a horizontal direction can create movement, if there is no wall at the other side of the piano.

To my body, lifting the piano, pushing a piano freely or pushing the piano against the wall all create muscle soreness, exhaustion, and burn calories. So who am I to believe, your physics text or my aching muscles?

##### Share on other sites

irregardless, if you are holding the piano stationary, there is no work done.

your muscles expend energy to keep applying the force but there is still no work done on the piano.

##### Share on other sites

but there is still no work done on the piano.

no net work, but you can look at it as work opposing other work. The force of gravity would accelerate the piano towards the ground. However, you must expend an equal amount of work directly in the opposite direction to keep the piano stationary.

So, yes you are doing work, it is just that there is an equal and opposite amount of work being done too.

##### Share on other sites

You win. I found a site

( http://www.physicsclassroom.com/Class/energy/u5l1a.html ) which explains it all in simple enough terms even for me.

It's the story of my life ... constantly expending energy, never getting any work done.

##### Share on other sites

no net work, but you can look at it as work opposing other work. The force of gravity would accelerate the piano towards the ground. However, you must expend an equal amount of work directly in the opposite direction to keep the piano stationary.

So, yes you are doing work, it is just that there is an equal and opposite amount of work being done too.

No, you are applying a force to counteract another force, but force does not equal work in the context of physics.

In general terms you are correct, and what you are doing can be called work, but so can sitting still, ruminating on a problem.

##### Share on other sites

Work = Force x Distance x Cos (@).

And you are only doing work on an object when it moves. This means that even if you are applying force against an object, if it isn't moving any distance, you aren't doing any work on it.

##### Share on other sites

You win. I found a site

( http://www.physicsclassroom.com/Class/energy/u5l1a.html ) which explains it all in simple enough terms even for me.

It's the story of my life ... constantly expending energy, never getting any work done.

And that's the geeky punchline of the joke. No work = no pay, and yet you have expended tremendous energy.

## Create an account

Register a new account