Recent content by 838

Greetings, I'm currently a month away from obtaining my undergraduate degree in Civil Engineering. My school (Located in CA) carries a decent rank within the engineering community and, from my experience, has a fairly solid curriculum. My issue is that I spent my first two years as an...

Homework Statement A 2-ft^{3} closed tank is filled with 0.30 lb (Weight) of gas, which is thought to be either oxygen or helium. A pressure gage attached to the tank reads 12 psi at a temperature of T=80F. Is it He or O_{2}? Why? Jeopardizing safety? Homework Equations...

I got into an argument with a mathematics grad student about the law of sines. He said that he has proven it to be wrong several times. I don't see how this is possible, given that the angles are opposing the sides, it doesn't seem possible for it to be EVER incorrect. I asked him to prove...

So, the hypotenuse BA when h=12 is 16.97, and when h=16 it is 20. To find the spring force, F=-k(xo-xf) =-4lb/in(16.97in-20in)=12.12lbs Now, to find the angle, which would be sin(\theta)=12/20 so, \theta = 36.869 degrees. Now, splitting components, y=12.12*cos(36.869)=9.696lbs = vertical...

Ah, my mistake, I wrote 8lbs on my paper and neglected to erase. x comp=16*sin(36.86)=9.6lbs y comp=16*cos(36.86)=12.8lbs So the collar weighs 12.8lbs.

Ok, so I've split the force components. 6.4lbs in the y direction, and 4.8lbs in the x direction. The vertical component is opposing gravity and the horizontal component is opposingthe bar that is holding the collar? This seems like it would make sense, since the system would be in...

The tension force from the rope? Also, the pulley would cut the tension in half, so there would be 8lbs on each side, correct? The angle that the pulley (B) makes with the collar (A) is 53.13 degrees, so would I break it into x and y components? Ah, no, that makes no sense. I am...

Homework Statement Collar A can slide on a frictionless vertical rod and is attached as shown to a spring. The constant of the spring is 4lb/in., and the spring is unstretched when h=12in. Knowing that the system is in equilibrium when h=16in., determine the weight of the collar. Home-made...

You answered your own question. You use the product rule and come out with xe^x+e^x. Good job. EDIT: Some teachers would prefer you to simplify your problem into (x+1)e^x, but either way, you got the right answer.

Ah, ok, I understand. I wasn't sure which root to choose for. Thanks a lot!

So if I'm understanding you correctly, it should look like this: k*(q1q3)/a^2=k*(q2q3)/(10+a)^2 since a < 0. I think... So we get a = 4.14 To test this, I can calculate the force between q1 and q3 and match it with q2 and q3, since they should be equal. So, k*(q1q3)/(4.14^2) = 23.31k and...

Homework Statement Two point charges (q1=+20 nC and q2=-40 nC) are placed 10.0 cm apart onlong the x-axis. Where can a third charge (q3=+20 nC) be placed so that the net electrostatic force on that charge is zero? Homework Equations F=k(q1q2)/r^2 The Attempt at a Solution It's...