Recent content by moonkey

  1. M

    Proving Stoke's Theorem for a Plane Curve

    Got it out Thanks again for your help LCKurtz
  2. M

    Proving Stoke's Theorem for a Plane Curve

    I think I might have been reading the question incorrectly (well hopefully). I feel like an idiot. I'll give it a go and hopefully it works out. Thanks LCKurtz
  3. M

    Proving Stoke's Theorem for a Plane Curve

    Homework Statement Let C be a simple closed plane curve in space. Let n = ai+bj+ck be a unit vector normal to the plane of C and let the direction on C match that of n. Prove that (1/2)∫[(bz-cy)dx+(cx-az)dy+(ay-bx)dz] equals the plane area enclosed by C. What does the integral reduce...
  4. M

    Prove the functions are unique in a volume, vector calculus problem

    Homework Statement In a volume V, enclosed by a surface S, the vector fields X and Y satisfy the coupled equations ∇×∇×X=X+Y ∇×∇×Y=Y−X If the values of ∇×X and ∇×Y are given on S, show that X and Y are unique in V. Homework Equations ∇.(A×B)=B.(∇×A)−A.(∇×B)...
  5. M

    Inverting Amplifier maximum output voltage

    Homework Statement I'm doing a physics lab that involves an inverting amplifier. I'm pretty crap when it comes to electronics. I've discovered that the output voltage won't go past 8Vrms. The amplifier is like the one here...
  6. M

    At what velocity should relativity be taken into account

    That makes perfectly good sense. Thanks Quinzio
  7. M

    At what velocity should relativity be taken into account

    Homework Statement I have exams coming up and I'm just looking for an idea of when relativity should be taken into account. For example I'm just going over a question involving photoelectric effect and potential fields and de Broglie and all that jazz and the final velocity of the electron...
  8. M

    At what velocity should relativity be taken into account

    Homework Statement I have exams coming up and I'm just looking for an idea of when relativity should be taken into account. For example I'm just going over a question involving photoelectric effect and potential fields and de Broglie and all that jazz and the final velocity of the electron...
  9. M

    Derivation of equation for star-planet system orbiting com

    Homework Statement (b) For a mass m1 in circular orbit with velocity v1, and a mass m2 orbiting with velocity v2 (about a common center of mass), the following holds: m1/m2 = v2/v1. Use this relation to derive an expression relating the mass and velocity of a star with the period and mass...
  10. M

    Determining the mass of the black hole at the centre of the Milky Way

    Homework Statement (2) A star orbits the centre of our Galaxy in a plane perpendicular to our line of sight. If the angular speed of this star in the sky is 40 mas (milli-arc-seconds) per year, calculate its velocity. Assume that the distance of the Galactic centre is 8 kpc. (3) If the...
  11. M

    Shining a laser pointer towards the star vega

    Thank you very much for the reply. Helped alot
  12. M

    Shining a laser pointer towards the star vega

    Homework Statement (1) A Physics lecturer, on a dark night, shines his laser pointer towards the star Vega. (a) Roughly, how many optical photons from the Sun per second enter the eye of an astronomer standing on a planet orbiting Vega ? Assume that 50 % of the light from the Sun is...
  13. M

    Stars: Creation, destruction and impact on the universe

    Hi all, Doing a project for 1st year special topics physics module in university and we're thinking of doing the project on stars. Just wondering if anyone might know of any good literature on the sublject that we could look into as part of our research. We have until mid January to do the...
Back
Top