physics

An electron is accelerated from rest through a potential difference that has a magnitude of 2.90 × 107 V. The mass of the electron is 9.11 × 10-31 kg, and the negative charge of the electron has a magnitude of 1.60 × 10-19 C. (a) What is the relativistic kinetic energy (in joules) of the electron? (b) What is the speed of the electron? Express your answer as a multiple of c, the speed of light in a vacuum.

  1. 👍 0
  2. 👎 0
  3. 👁 1,310
  1. relativistic KE=Voltage*charge

    to find the speed,

    relastivistic KE=restmass*c*gamma

    gamma=(1/sqrt(1-(v/c)^2) -1)

    so take relavitic KE, divide by restmass, then divide by speed of light.
    result=gamma

    Now ignore the -1 in the gamma, look at it later. If v is approaching c, it can be ignored.

    square both sides (ignoring the -1)
    solve for v in terms of c. If v/c is within .5 or greater, use that v, it is pretty accurate. If v/c is greater than .5, you have to consider the -1 in gamma. You can do that by expanding the gamma with the binomial expansion, and there are programs to do that, and I am told calculators to do it. I would not relish doing more than a few terms by hand.

    1. 👍 0
    2. 👎 0
    👨‍🏫
    bobpursley

Respond to this Question

First Name

Your Response

Similar Questions

  1. physics

    if electron are caused to fall through a potential difference of 100000 voltage , determine their final speed if they were initially at rest.

  2. physics

    An electron is accelerated from rest to a velocity of 2.0x10^7 m/s. a) if the electron travelled 0.10m while it was being accelerated, what was its acceleration? b)How long did the electron take to attain its final velocity?

  3. Electromagnetism

    A particle with a mass of 6.64x10^-27 kg and a charge of +3.2x10^-19 C is accelerated from rest through a potential difference of 2.45x10^6 V. the particle then enters a uniform magnetic field of strength 1.60 T. a) Find the

  4. physics

    An electron is accelerated horizontally from rest in a television picture tube by a potential difference of 5400V . It then passes between two horizontal plates 6.1cm long and 1.2cm apart that have a potential difference of 250V

  1. physics

    During a lighting discharge, 30C of charge move through a potential difference of 1.0 X 10^8V in 2.0X10^-2s. The energy released by this lighting bolt is: a)1.5 X 10^11 J b) 3.0 X 10^9 J c) 6.0 X 10^7 J d) 3.3 X 10^6 J e) 1500 J

  2. Physics pls help

    An electron is accelerated by a 6.4 kV potential difference. The charge on an electron is 1.60218 × 10^−19 C and its mass is 9.10939 × 10^−31 kg. How strong a magnetic field must be experienced by the electron if its path is

  3. physics

    An electron (mass m = 9.11 * 10^-31 kg) is accelerated in a uniform field vector E ( E =1.45 * 10^4 N/C) between two parallel charged plates. The seperation of the plates is 1.10 cm. The electron is accelerated from rest near the

  4. Physics

    A uniform electric field of magnitude 370 N/C pointing in the positive x-direction acts on an electron, which is initially at rest. The electron has moved 2.70 cm. (a) What is the work done by the field on the electron? J? (b)

  1. Physics

    The anode (positive terminal) of an X-ray tube is at a potential of +115 000 V with respect to the cathode (negative terminal). (a) How much work (in joules) is done by the electric force when an electron is accelerated from the

  2. physics

    A tungsten target is struck by electrons that have been accelerated from rest through a 24.5-kV potential difference. Find the shortest wavelength of the radiation emitted. (in nm)

  3. physics

    If a proton is accelerated from rest through a potential difference of 1500 V, find its final velocity. proton mass = 1.67 x10−27 kg

  4. physics

    An electron is accelerated in the uniform field E = 2.0 x 104 N/C between two parallel charged plates (Negative charged plate is on the left and positively charges plate is on the right). The separation of the plates is 1.5 cm.

You can view more similar questions or ask a new question.