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Homework Help: Acceleration of a Particle Due to Magnetic Field

  1. Apr 15, 2016 #1
    1. The problem statement, all variables and given/known data
    A particle (mass = 2.0 mg, charge = -6.0 μC) moves in the positive direction along the x axis with a velocity of 3.0 km/s. It enters a magnetic field of (2i + 3j + 4k) mT. What is the acceleration of the particle in component form?

    2. Relevant equations
    F = q(vXB)
    F = ma

    3. The attempt at a solution
    First convert all values to SI units:
    mass = 0.002 kg
    q = -6x10^-6 C
    v = 3000 i m/s
    B = (0.002i + 0.003j + 0.004k) T

    Find vXB:
    vXB = -12j + 9k

    Plug vXB and q into F = q(vXB) and find a:

    F = (-6x10^-6)(-12j + 9k) = ma
    a = (7.2x10^-5 j - 5.4X10^-5 k) / 0.002
    a = 0.036j - 0.027k m/s^2

    However the correct answer provided to me is:
    (36j - 27k) m/s^2

    I think i made a mistake converting the units for B from mT to T. i'm not sure how to convert units for vector components.

    Last edited by a moderator: Apr 15, 2016
  2. jcsd
  3. Apr 15, 2016 #2
    Never-mind I found my mistake. I didn't convert the mass correctly.
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