Recent content by syang9

wow, thanks for that, Mute! i'd always wondered why you needed to multiply the integrand by the density of states. fantastic explanation!

so the answer is sqrt(14)?

i thought speed was a scalar. doesn't that mean it's the magnitude of the resultant vector of the two components?

alright, i know this is really basic stuff, so please bear with me. let's say i have a box or something that is sliding horizontally at 2m/s across a table. all of a sudden it falls 0.5m to the ground. what's the speed of the box right before it hits the floor? okay, so it's pretty easy...

okay, i get that enthaply is a measure of the thermodynamic potential of a system. but what exactly are the 'pressure' and 'volume' components of this? (I'm referring to the definition H = U + pV). I've read that it's "motivated" by the isobaric expansion of a gas inside a cylinder, but how does...

Okay, I think I was confused because I didn't really understand the definition of a 'lever arm.' The lever arm is defined as the distance from the rotation point to where the force acts perpendicular. So the lever arm for F would be L, and the lever arm for the weight of the box would be L/2...

Let's say you put a box on a board, like this. (the dot represents a fulcrum point). Let's say the center of mass is exactly halfway between the fulcrum and the edge of the board. http://dl.getdropbox.com/u/119319/board.jpg Now let's say you exert an upward force F in the direction of the...

What's wrong with this statement: 'Ideal fluids always flow from high pressure to low pressure'? Could someone give me an example of where this is not true?

have i got it?

okay, i think i get it. so you're saying that, in order for the siphon to work, water has to make it past the up leg of the siphon. the weight of that water is pV = pAy, and the only thing that can provide the necessary force to support this weight is the 1atm of pressure that comes from the...

Hi there. Came upon another tricky question in my mcat prep book.. this one makes no sense to me. https://dl-web.getdropbox.com/get/siphon.PNG?w=389b1d3a "A siphon is used to draw water from a water tower. What is the approximate maximum height d at which the siphon will be capable of...

okay, i understand now.. the pulley system works because it reduces the torque that the mass exerts on the center rotation point, and increases the torque that the user (pulling on rope a) exerts on the center rotation point. increasing pulley B diameter would increase the clockwise torque from...

http://dl.getdropbox.com/u/119319/pully-1.jpg the book says the answer is C because 'increasing the diameter of the pully decreases the amount of force required to pull rope A'. I don't understand why increasing the diameter of pully B does not have the same effect (i.e., why D is incorrect.)

so then, the reason that two masses launched together reach the same height is because the launch speed is determined by the total mass, right? after they are launched, they must reach the same height because they are traveling at the same speed.

also, why is it incorrect to simply equate the elastic potential energy to the gravitational potential energy? this yields an expression that is clearly dependent on mass.