Recent content by aa_o

Yeah, that makes sense. I think there was a lot of assumptions that had to be made that wasn't explicitly stated in the problem. But thanks a lot for the help!

Thanks, mjc123. So n is constant for the whole system (tire + pump), but the volume then changes (compresses). Ahh, i think that gauge was the missing piece. I didn't know about the meaning of gauge and simply skipped over it without paying much attention. With that information (P1 = P0 +...

Okay. So the pump has a start state of: P0 * V0 = n0 * R * T0 And end state of: P1 * V0 = n1 * R * T1 I thus have 2 unknowns i need to solve the problem T1, which is what i need in the end, and the ratio of the number of molecules between the 2 states. I just can't find that extra connection...

I'm not sure that this is an adiabatic process. As far as i can read, it is adiabatic if no HEAT or ENERGY is added. But pumping in molecules that are a non-zero temperature is an addition of energy, no? Anyway - my solution with the assumption of an adiabatic process. (skipping units for...

I figured that deriving from first principles would give me the best understanding of the concept. I did this and came up with the same answer as the book. Thanks for the help guys!

I don't think that's right. In the problem the origin is not specified. In the books' solution we have a point at x=0, y=0, so the origin must be on the surface of the lens itself.

Homework Statement [/B]Homework Equations 1/s+n/s′=1/f where s is distance from source to diffracting surface, s' is distance from diffracting surface to focus, f is the focal length, n is the refractive index. The Attempt at a Solution Since we have parallel beams, we have s = infinity so the...

Ahh yes! Thanks a lot. Quick last question: Do you know if the different symbol for mass is a mistake in the problem? Or am i missing some connection? To anyone else stuck here: Just note that angular momentum is conserved, meaning: I_t * ω_0 = I_t_a * ω_a (ω_a is angular velocity after...

Ahh, okay. There's conservation of angular momentum. I'll work it out and return with what i got.

Because the moment of inertia of the mechanism is unchanged. Since I = L / ω (L is the angular momentum here!). But maybe I've been to quick in that assumption. All I know is that I is constant for the mechanism - not that L or ω is constant. Am I on the right track?

Homework Statement Homework Equations The Attempt at a Solution The moment of inertia before collapse is for each rod: BEFORE COLLAPSE:[/B] Ib = ∫(L2 + x2) dm = m/L ∫(L2 + x2) dx = 4/3 * m * L2 We have 8 of these plus the inertia of the mechanism, giving a total I, It = 8 * Ib + Ik =...

Yes, so it is not shorted.

Can you draw a line from B to D without going through any components?

It went to making a hole in the pendulum and generating heat in the form of friction?

Homework Statement Homework Equations Conservation of momentum: m1*v1 + m2*v2 = k Conservation of mech. energy 1/2 * m * v^2 + m * g * h = k The Attempt at a Solution Why can't i just use conservation of energy to solve this one? I know that the bullet contains all the kinetic energy before...