Recent content by Fizic

1. The classic. Why did the physics major cross the road? He overslept because he was studying physics really late. 2. Another classic The physics major goes up to the math major and says "we are both studying pretty difficult material." 3. A third classic How many physics majors does it take...

Two blocks (m=1.0 kg and M=10 kg) and a string (k=200 N/m) are arranged on a horizontal, frictionless surface (in the picture m rests atop M). The coefficient of static friction between the two blocks is .40. What amplitude of simple harmonic motion of the spring-blocks system puts the smaller...

My bad, it was supposed to be x/2, not 2/x. I think it's infinity but I can't integrate e^(-2/y)/y.

You're right, it should be ∫(2,2y) instead of ∫(2y,∞) I'm still getting ∞

Evaluate the integral ∫(2,∞) ∫(2/x,∞) 1/(y^2)*e^(-x/y) dydx by changing the order of integration. I get ∫(1,∞) ∫(2y,∞) 1/(y^2)*e^(-x/y)dxdy etc. etc. etc. I get to ∫(1,∞) (e^(-2)/y) dy Which is (ln∞-ln1)/e^2 = ∞ Does this thing not converge?

Ah... yes. Okay. rho from 0 to sqrt18 theta from 0 to pi/2 phi from 0 to pi/4 integrating (rho)^3*sin(phi) I got 149 but that's too big. Edit: Woops. Did theta from 0 to 2pi in calculations. Divided by 4 and got 32.266.

I don't know how to draw the first octant because I'm unsure of how to draw the limiting surface on X. Z is a cone and sphere. Y is two planes. I feel like the upper limit on X should be sqrt(9-y^2) instead of sqrt(9-x^2). In that case it would be easy to re-parametrize.

Z is limited on bottom is a cone and on top a sphere with radius sqrt18. Y is limited on the left by the xz-plane and on the right by y=3. X... I don't know.

∫03∫0sqrt(9-x2)∫sqrt(x2+y2)sqrt(18-x2-y2) (x2+y2+z2)dzdxdy x=\rhosin\varphicosθ y=\rhosin\varphisinθ z=\rhocos\varphi Change the integrand to \rho and integrate wrt d\rhodθd\varphi I don't know how to find the limits of integration. Normally I would draw a picture and reason it out...

Homework Statement You and a group of female and male friends stand outdoors at dusk watching the Sun set and noticing the planet Venus in the same direction as the Sun. An alien ship lands beside you at the same instant that you see the Sun explode. The aliens admit that earlier they shot a...

This is my first problem set involving work, so I want to make sure I'm doing it right. Thanks for checking. Homework Statement To push a 25.0 kg crate up a frictionless incline, angled at 25.0° to the horizontal, a worker exerts a force of magnitude 209 N parallel to the incline. As the...

Homework Statement The two blocks (with m=16kg and M=88kg) shown in Fig. 6-56 are not attached. The coefficient of static friction between the blocks is \mustat=0.38, but the surface beneath the larger block is frictionless. what is the minimum magnitude of the horizontal force \vec{F}...

Honestly I'm not sure if I've made any mistakes here, but I've been having considerable difficulty with tension problems. This is also the first pulley problem I've attempted, so I'm sure I've made a blunder or two somewhere. If someone could review what I've done so far that would be very...

Thanks∞ to you. srsly

Wait a sec... Isn't that what I did in post #11? Maybe you didn't see; I edited it.