# Recent content by Seraph404

1. ### Hydrostatic Force and Pressure

Homework Statement A semicircle with radius 3 m is submerged vertically in water so that the top is 1 m above the surface. Express the hydrostatic force against one side of the plate as an integral and evaluate it I'm not getting the correct answer, so can someone help me to understand my...
2. ### Simple Arc Length Problem

Haha. I apologize. The question I asked was actually very simple compared to the other topics being posted in this forum. The link you sent me looks like cases in which you would use trig substitution (though, that doesn't seem to be how the problems are worked out). But in the problem above...
3. ### Simple Arc Length Problem

Homework Statement x = 1+3t^2 y=3+2t^3 0<= x <=4 Homework Equations L = integral from a to b of \sqrt{[dx/dt]^2 + [dy/dt]^2} dx The Attempt at a Solution dx/dt = 6t dy/dt = 6t^2 L = integral from 0 to 4 of \sqrt{(6t)^2 +(6t^2)^2} dx = " \sqrt{36t^2 +36t^4} dx = "...
4. ### I think it's a conservation of energy problem

I looked up on google what MeV stood for and I saw that it was 1 electron volt times a million. Maybe my source was wrong *shrug*. So is b significant at all in finding the closest distance that the alpha particle comes to the lead nucleus?
5. ### I think it's a conservation of energy problem

So far is this the correct setup? L1 = L2 P0b = p(Rmin) [Rmin is the minimum distance the two particles get to each other] v0b=vf(Rmin) [mass doesn't change so I canceled it] K0+U0 = Kf+Uf K0 = .5mV0^2 = 1 mil(1.602E-19) J [ I can use this to find initial velocity, assuming that I can use...
6. ### I think it's a conservation of energy problem

So then it's just approaching at an angle then? That's the only difference between this and what I described?
7. ### I think it's a conservation of energy problem

Wait... does the alpha particle cause the lead nucleus to rotate?
8. ### I think it's a conservation of energy problem

Homework Statement An alpha particle with kinetic energy 10.5 MeV makes a collision with lead nucleus, but it is not "aimed" at the center of the lead nucleus, and has an initial nonzero angular momentum (with respect to the stationary lead nucleus) of magnitude L = p_0 b, where p_0 is the...
9. ### Electric potential on long insulating cylinder

Nevermind. I think I just need to clear the memory out the memory in my calculator. Thanks a lot!
10. ### Electric potential on long insulating cylinder

So... S = 2\pirh ES = \lambda*h/\epsilon0 E(r) = \lambda*h/(\epsilon02\pirh) h cancles.... E(r) = \lambda/(\epsilon02\pir) And now... v = \int E(r) * dr Is that right?
11. ### Electric potential on long insulating cylinder

Is \intdl the distance from the surface of the insulating cylinder to the point at which I'm measuring potential? I'm guessing not because I'm totally not getting the right answer.
12. ### Electric potential on long insulating cylinder

Homework Statement A long, insulating cylindrical shell of radius .06 m carries a linear charge density of 8.5E-6 C spread uniformly over its outer surface. What would a voltmeter read if it were connected between the surface of the cylinder and .04 m above the surface? Homework Equations...
13. ### Work needed to pump water out of spherical tank

Homework Statement A spherical tank is full of water. If radius r = 3m and height h = 1.5m, find the work W required to pump the water out of the spout. (Use 9.8 for g and 3.14 \pi) Homework Equations Work is the integral from a to b of f(x)dx. The Attempt at a Solution Volume= area *...
14. ### Electric Field: not quite getting the correct answer

Homework Statement E1 = 2.9E4 N/C E2 = 8.6E4 N/C Both fields are uniform Homework Equations flux = \int Eperp*dA = Qencl/ \epsilon0 The Attempt at a Solution flux1 = E1cos(30)(.05m)(.06m) flux2=E2cos(30)(.05m)(.06m) (flux1+flux2) = Qencl/ \epsilon0 Homework...
15. ### Gauss's law; large sheet

Okay, I changed the problem.