Recent content by BobRoss

  1. B

    Simple harmonic motion - Find amplitude given period

    So if I find ΔLo=mg/k ΔLo=21/130 ΔLo=0.162m Then the ΔLo+A=0.25m Is that correct? So if I solve for A we get 0.088m. Is that the amplitude here?
  2. B

    Simple harmonic motion - Find amplitude given period

    Okay, I think maybe I was initially interpreting the question wrong. When it says "At a certain instant the spring is stretched 0.25 m beyond its relaxed length (the length when no object is attached) and the block has zero velocity", this just means that they've attached the block and it is at...
  3. B

    Simple harmonic motion - Find amplitude given period

    Ya I knew that. But it says "At a certain instant the spring is stretched 0.25 m beyond its relaxed length (the length when no object is attached) and the block has zero velocity". So if the block is released and reaches a point where it has zero velocity, that means that it is at it's maximum...
  4. B

    Simple harmonic motion - Find amplitude given period

    Okay so for a.) I just did the equation Fnet=kx-mg using x=0.25 and I got Fnet=11.5 N, and that came out correct. I entered 0.25 for the amplitude for b.) and it tells me that that is incorrect. And I used x=0.25 in my equation for d.) to find the maximum kinetic energy and got 4.06 J and it...
  5. B

    Simple harmonic motion - Find amplitude given period

    Hmm, that is what I had initially entered as my answer for b.) the first time I did the question but when I submitted it, it came back as incorrect...
  6. B

    Simple harmonic motion - Find amplitude given period

    Ahh okay I got it. I set ω2xm=9.81 then I solved for ω and found the frequency to be 2.03 Hz from that. Thanks for the help on this one! I have one more spring question that I am struggling with and am hoping you can help there too. I thought I knew what I was doing for it but I only got 1/4...
  7. B

    Simple harmonic motion - Find amplitude given period

    Sorry I'm not getting it. I know that f=ω/2π but I'm not sure what amplitude has to do with it or even what it means by the max frequency that the block and piston will be in contact for.
  8. B

    Simple harmonic motion - Find amplitude given period

    Wait, I got it. I found the max downward acceleration to be 9.81 m/s2 and I divided that by ω2 which gave me 1.747 m. Although I am having a bit of trouble understanding the second part to the question. b.)If the piston has an amplitude of 6.05 cm, what is the maximum frequency (in Hz) for...
  9. B

    Simple harmonic motion - Find amplitude given period

    Ok I'm following everything you are saying but I still don't understand how to find minimum amplitude where that occurs. And I don't know how to find cos(ωt+∅) either.
  10. B

    Simple harmonic motion - Find amplitude given period

    Hmm, I found a thread on here with a very similar question to this one that said they separate when the acceleration is at a maximum. Then it said that the ω2xm of the equation a(t)=-ω2xmcos(ωt + ∅) gave the maximum acceleration, although it never explained how to find xm. Is that not correct?
  11. B

    Simple harmonic motion - Find amplitude given period

    Homework Statement A block rides on a piston that is moving vertically with simple harmonic motion. (a) If the SHM has period 2.65 s, at what amplitude of motion will the block and piston separate? Homework Equations x(t)=xmcos(ωt + ∅) a(t)=-w2xmcos(ωt + ∅) Where xm is the amplitude...
  12. B

    Calculating second ionization energy of He

    Homework Statement The equation En=-Z2RH/n2 gives the energy (according to the Bohr model) of the energy levels available to an electron in any hydrogen-like atom. Calculate the second ionization energy of He(in J). The second ionization energy of He is the ionization energy of He+. Homework...
  13. B

    What is the charge on the oil drop in Millikan's oil drop experiment?

    Okay, so then my original answer is correct?
  14. B

    What is the charge on the oil drop in Millikan's oil drop experiment?

    Doesn't the charge have to be an integer multiple of the elementary charge (1.60x10-19C) ?
Back
Top