Recent content by winhog

The easiest way to see it is a concrete example I think. Take n as 5... then (n+1)! is 6! , which is 6*5*4*3*2*1. (n+1)n! is the same thing because n+1 is 6, then n! is 5*4*3*2*1, giving you 6*5*4*3*2*1. edit: posted late I guess :rolleyes:

They give height = 2.4 meters, n = 0.1 mol, mass = 1.4 kg, and that the gas is initially at STP. I calculated the area at 0.93 m^2.

Hmmm, I'm back to my initial problem then, where my answer comes out to something like 0.2 millimeters. I guess it makes some sense since .1 moles of gas can't hold much up unless very compressed, but I've never been asked a problem with such a ridiculous answer from this book before.

Sorry, I'm still having trouble. Using your formula, with m = 1.4 kg, T = 273 K, n = 0.1 mol h = (.1)(8.314)(273) / ((1.4)(9.8)) = 16.5 meters. The units all work out and everything, but the given height of the cylinder was only 2.4 meters. I know the piston would not shoot up to...

Thanks very much! Though, it seems odd that the initial height of the cylinder they gave me was useless...wasn't it? :confused:

I'm having some trouble with a question involving a piston pressing down on an enclosed gas. I'm given the height of the cylinder, the number of moles of gas, the mass of the piston, and told that initially the gas is at STP. I need to find the height of the piston when the system is in...

Thanks for the help guys!

If I take the derivative with respect to, say, x, can I assume y and z are constants? If so, I messed up on a pretty simple problem :blushing:

Hmmm...I think my problem might be I've never learned how to take a vector derivative and this might be above my head mathematically :confused: Maybe I can separate the potential energy into x and y components...but i really don't know how. I guess since the particle is on the x-y...

I have a problem on my homework that says the potential energy of a particle is given by its position in the x-y plane according to P.E. = x^3 + 8x^2 + 34yz and I have to calculate the force on the particle at point (x,y,z), and all equilibrium points. dU = 3x^2 dx + 16x dx + 34y dz +...

Thanks guys, I managed to figure out the answers! :smile: But I'm still having some conceptual problems. I got the vertical components of friction and normal forces, setting them to 0 when added with weight. This allowed me to get the magnitude and direction of all 3 of those forces...

OK...the entire system is going to be accelerating horizontally due to the applied force, so there will be some horizontal force F' on the block..which is unknown. The force of gravity, mg, is known and is 4.9 N downards. The normal force is F(gravity) * sin(35) ... if the block is not...

Aha, that makes sense. Thanks for clearing that up!

In that case...why would a person on a spaceship moving quickly age slower than those on earth? (like in the grandfather paradox) Is it simply because the spaceship accelerated while the Earth didn't? Couldn't that also be considered the Earth accelerating away from the spaceship?

I have learned that objects moving at high velocity experience time dilation, among other things, and that there is no ultimate frame of reference in the universe. If this is so...say two galaxies pass by each other at near the speed of light...in which one would time be moving slower? There's...