Recent content by Matthew Travers

  1. M

    Predictions for antimatter are weird

    Is antimatter time-reversed negative matter? If so, then it would behave like ordinary matter electromagnetically BUT Newton's grav would yield like mass charges attract and unlike masses repel. Ie, a combination of antimatter and matter does not make a diametric drive due to the time inversion...
  2. M

    Checking simple differential product rule

    Thanks Ray and Ehild for your indulgence and patience. Merry Christmas and a happy new year to you and all the staff at physics forum. It's a pleasure becoming that little less ignorant.
  3. M

    Checking simple differential product rule

    One last question please? When I applied the product rule above, I ended up with a a(dm/dt) term. Does this have a physical meaning?
  4. M

    Checking simple differential product rule

    Thanks mate. I had missed that...so energy rises parabolically, power rises linearly, and change in power is a constant when force and acceleration are constant.
  5. M

    Checking simple differential product rule

    First of all, thank you for the feedback I appreciate the distinction for the first equation and pointing it out for me. I must be a bit thick. To me it seems that if acceleration is constant, then energy is being delivered at a constant rate, ie power stays constant and therefore rate of power...
  6. M

    Checking simple differential product rule

    Homework Statement Saw a calculation that put differentiation of power in terms of acceleration as follows: E=Fs dE/dt=Fv=P dP/dt=Fa=ma^2 It doesn't make sense to me because if power was changing, acceleration must change. Correct me if I'm wrong, but shouldn't the product rule be applied...
  7. M

    Graphene Conductivity: Testing the Resistance

    What I found was perhaps not electrostatic discharge. Apparently graphene demonstrates negative resistance or negative differential resistance where an increase of current through the material counter intuitively leads to a drop in voltage. Researchers intographene transistors are seeking to...
  8. M

    Labourer with physics and engineering interests

    Thanks mate. I don't knowwhether to be relieved or alarmed about that though:nb)
  9. M

    Graphene Conductivity: Testing the Resistance

    Hang on, just caught up to you...earth everything to discharge and then measure after disconnecting earth. Will try that and a couple of other ideas like putting foil on the other side of the polyethylene and connecting that to the sample so it acts like a shorted cap. Cheers mate
  10. M

    Graphene Conductivity: Testing the Resistance

    Thanks for that. So if I connected the sample to Earth first, that would eliminate the faulty reading?
  11. M

    Graphene Conductivity: Testing the Resistance

    Hi I've made what I think is graphene. I first put the solution on cardboard and then I put some on polyethylene. When they had dried, I tested conductivity with a digital multimeter with the scale set on megaohms. The cardboard was nonconducting, but the sample on poly to my astonishment showed...
  12. M

    Labourer with physics and engineering interests

    Hi folks Amateur experimenter here with only rudimentary maths skills. I have the most unfortunate and embarrassing tendency of being most confident in a topic when I am only just starting to learn something about it. I am grateful for being able to participate in a forum where more...
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