Recent content by Aerosion

it's a question I've been wondering for a little while: why do we learn about resistors and capacitors, etc in a general physics course? all the other coursework is about things that happen naturally in nature: mechanics, gravity, lenses, magnetism; but then we devote several chapters to...

Homework Statement y''+2y'+y = 4t^2 - 3 + (e^-t)/t of course i evaluated the general soltuion to be c1e^-1t + c2te^-1t but now how do you do the right part? i tried y=At^2+Bt+c+1/(Dt+E)*e^-t as a solution but after differentiating it twice and putting it into the eqaution i got...

Homework Statement so here's my equation: dy/dx=(xy+3x-y-3)/(xy-2x+4y-8) so what i did first was factor out the right side =(x+1)(y-3)/(x+4)(y-2) then i did a bunch of manipulation to get the ys on one side and the xs on another (i won't write this out right now but if anyone...

Homework Statement i'm trying to find two constants in the same equation. its an initial value problem there's a two parameter family x=c1cost+c2sint with initial conditions x''+x=0, x(pi/6)=1/2, and x'(pi/6)=0 so I'm trying to find c1, and i equate the problem to 1/2 and subsitute...

Homework Statement yet is approaching negative infiniti? We were discussing a question that went "suppose f double prime (x)>0 and x ranges from negative infiniti to infiniti, and f(a)=0. Prove or disprove that f(x) is bounded below." The man said that e^-x - x had a second derivative...

Homework Statement Okay, three electrons are arranged in a right triangle-like shape. The electron where the right angle goes is +2e, and the other electrons are +e. And at the half point of hte hypotenuse there is a point P and they want hte magnitude of the net electtric field...

Well, yeah, I thought of that, but wouldn't that just be the force in the y direction? Like, shouldn't there also be a force in the x direction, since it's on an inclined plane and all? That's the acceleration I'm having trouble finding. See, it's that that I was guessing at in the above...

Homework Statement Two blocks of wieghts 3.6N and 7.2N are connected by a massless string and slide down a 30 degree inclined plane. The coefficient of kinetic friction b/t the lighter block and the plane is 0.10, that b/t the heavier block and the plane is 0.20. Assuming the lighter block...

Yes, yes, I forgot to add that the force is at 40 degrees in the fourth quadrant, or -40 deg, or 320 deg, whichever you like. The force is being applied downward, below the horizontal, if you will. But to find the normal force shouldn't be any different, should it? Normal force is upwards...

Homework Statement An easy question, but I'm not getting it: A 3.5kg block is pushed along a horizontal floor by a force F of mag 15N at an angle of 40 deg with teh horizontal. The coefficiennt of kinetic firction b/t the block and the floor is 0.25. Find the frictional force on the block...

Oh oh...and the work I did for PE is... I used the change in potential energy equation -q=(integrate)E*ds, and subsituated 3microcoloumbs for q, 2kn/C for E, and 0 and 4 for the definite integral, such that it looked like -3mC*(integrate fr. 0 to 4)2 ds.

Well, that's the thing: I don't know how to find the kinetic energy of a charge; as in I'm unclear as to what the formula is. That's why I said that I don't want anyone to think that they're doing homework for me: because I don't know how to get started. Like, I know that KE=1/2mv^2, but I...

Homework Statement I don't want to sound like I'm asking anyone to do my homework for me, but I really don't know how to find this. Let me give an example problem: A uniform electric field of 2kN/C is in the x direction. A point charge Q=3 microcoloumbs initially at reast at the origin...

http://www.ac.wwu.edu/~vawter/PhysicsNet/Topics/ElectricForce/gifs/Axis-of-Loop00.gif Here's a kind of good picture I found. Mine is like this one, except without the blue part at the end. That's how I was finding my r. EDIT: This isn't my problem btw...just a pic I found on Google search...

Hmm...it's a bit unclear without a picture, sorry. The reason I turned r^2 into (r^2+x^2)^1/2 is because the radius of the circle and the x would make two sides of a triangle. The two lines woudl meet at the center of the circle, and I just drew the hypotenuse joining the two lines at their...