Recent content by pelmel92

Homework Statement A comet of mass m moves in a parabolic orbit in the ecliptic plane (the plane of Earth’s orbit), so its perihelion distance ρ (its closest distance to the Sun) is less than Ro (the orbital distance of the Earth around the Sun) and occurs when θ = 0 for the comet. (The...

Alrighty, figured that bit out on my own as well... polar coordinates work out nicely.

Ah, I think I may have figured it out... x isn't actually changing here, so my attempts to relate it to y were completely unnecessary? The answer then (I think) would be: φ(x) = --Gk[√(x^2+L^2) - x] . Part b has me a bit stumped though... help would be lovely.

Homework Statement GRAVITATIONAL POTENTIAL AND FIELD DUE TO A “THIN” ROD A thin rod of length L lies along the +y-axis, with one end at the origin (see diagram). Assume: • The rod has length only- no thickness in other directions. • The density of the rod increases proportionally to...

i guess that's always possible... it's a webassign homework, which has been known to fudge the grading on occasion... but i feel much better about it if you think my approach looked good, thanks for all the help :)

hold on...thought i caught it but I'm still a bit confused here... .5MR^2ω1 +mR^2ω1= .5MR^2ωf +mvR so .5MR^2ω1 +mR^2ω1 -mvR = .5MR^2ωf and (.5MR^2ω1)/(.5MR^2) +(mR^2ω1)/(.5MR^2) - (mvR)/(.5MR^2) = ωf right? which means that ω1 +2(mω1)/M - 2(mv)/(MR) = ωf maybe I'm just being dense...

i imagine you're meant to use the relationship ∆S=k*log(w) where ∆s=entropy change, k is 1.380 6504(24)×10-23 J/K, and w is work... work is kinetic energy, so... got it?

ωf= ω1 + 2mω1/M -2mv/(MR) do i just suck at algebra?

actually ignoring friction, as long as you're raising both the same height (in this case, from the ground to the truck bed) the **work will be the same regardless of the path** (i.e. the steepness of the ramp). work is force times distance, but while the force required to lift something up a...

Homework Statement Consider a cylindrical turntable whose mass is M and radius is R, turning with an initial angular speed ω1. (a) A parakeet of mass m, after hovering in flight above the outer edge of the turntable, gently lands on it and stays in one place on it, as shown below. What is the...

if it helps, here's the diagram they give http://www.webassign.net/tipler6/7-p-094.gif

well i started off with .5kx^2=mg∆H but since the question defined h as the height the object fell when it first touches the uncompressed spring, i thought i would probably need to consider that in my ∆H. so from there P.E.=mg(h+xsin(ø))=.5kx^2 then in quad format: 0=.5kx^2 - mgsin(ø)x -mgh

thanks for giving me a hand :) do you mean i should subtract the square root instead of add? or should i have originally set .5kx^2 equal to -mg∆h? I'm a little confused as to how to handle this problem :/

haha whoops, i copied that over without the h's, but the answer comes up wrong even as √(2mgh/h) or √(-2mgh/k)

Homework Statement A block of mass m starts from rest at a height h and slides down a frictionless plane inclined at angle θ with the horizontal, as shown below. The block strikes a spring of force constant k. Find the distance the spring is compressed when the block momentarily stops. (Let...