Recent content by qswdefrg

  1. Q

    Right Hand Rule

    Homework Statement An alpha particle (two protons and two neutrons) traveling east at 2.0 x 105 m/s enters a magnetic field of 0.20 T pointing straight up. What is the force acting on the alpha particle? Homework Equations F = qvBsinø The Attempt at a Solution With the fingers of the right...
  2. Q

    Error Analysis

    Homework Statement Hello. One section of my lab requires me to calculate the percentage error in the magnetic field at the closest separation. My data for that point in time are as follows: x1=0.6 cm \pm 0.1 cm v1=0.006 m/0.02 s = 0.3 m/s Homework Equations where delta x, y...
  3. Q

    Energy conservation problem (need closure)

    Yes the h and r should be switched; silly error my bad. finding h in part a): mgh = 0.5mv2 + mg2r at the top min. speed is sqrt rg mgh = 0.5mrg + mg2r simplify h = 2.5r thanks so much for your help. i (finally!) got it.
  4. Q

    Energy conservation problem (need closure)

    Never mind my previous post; I think I've got it now. at the top: v2= 4g(r-h) Fnet=Fc=Fn+Fg Fn=mv2/r - mg sub in v2 Fn= {[4mg(r-h)]/r } - mg at the bottom: v2= 4gh Fnet=Fc=Fn-Fg Fn=mv2/r + mg Fn= (4mgh/r) + mg at the end: Fn= mg :confused: *fingers crossed*
  5. Q

    Energy conservation problem (need closure)

    I got v2= g(2h-r) So is the equation is Fn+Fg=ma? Sub in velocity and I get Fn=2mg[(h/r)-1]. Is this correct?
  6. Q

    Energy conservation problem (need closure)

    at the top of the loop Fnet = FN - Fg = ma FN = mv2/r + mg FN = m(v2/r + g) this is similar to the answer I had before. I realize now that I hadn't used the 2h at all. Am I supposed to use energy conservation to figure this out?
  7. Q

    Energy conservation problem (need closure)

    Homework Statement the small mass m sliding without friction along the looped track is to remain on the track at all times, even at the very top of the loop of radius r. a) calculate, in terms of the given quantities, the min. release height h. if actual release height is 2h, calculate...
  8. Q

    1D kinematics

    Homework Statement You are crossing a narrow bridge 1km long when you notice a truck approaching at 90km/h. If you can run at 5m/s, how far from the far end must you be if you could reach either end just before being hit by the truck? My attempt Displacement between the two...
  9. Q

    Juggler Problem

    This might help in the visualization of the problem: :)
  10. Q

    Coefficient of Friction Problem

    Just do it with the variables. You'll find that you don't need to know the mass to solve for mew. :)
  11. Q

    Coefficient of Friction Problem

    Start off by finding the x-, y-components of Fg. Then you'll be able to solve for Fn.
  12. Q

    Juggling/Projectile Motion problem

    Homework Statement A juggler can transfer a ball from his left hand to his right hand in 0.2s. If he is juggling 5 balls and releases them from a height of 1.5m what is the min. height of the ceiling? Homework Equations symmetrical trajectory equations: t = 2v1sintheta / g delta_d =...
  13. Q

    Solving for d

    thanks so much!
  14. Q

    Solving for d

    Homework Statement I have this equation, but I'm having trouble solving for the unknown :/ I know that d is 109; I just don't know how to get it. see below Homework Equations -dsin35 = -4.9(dcos35/25)^2 The Attempt at a Solution -dsin35 = -4.9d^2 cos^2(35)/25^2 -dsin35 = -4.9d^2 cos(35) x...
  15. Q

    Golf ball question

    If a = -9.8 m/s^2, then I'd be able to calculate dy... so would I have to repeat this calculation until v2 = 0 and add up all the displacements? Or is there an simpler method?