Math Problem Statement

What is the final speed of an electron (in m/s) accelerated from rest through a voltage of 50kV by a negatively charged van de Graaff terminal?

Solution

The final speed of an electron accelerated from rest through a voltage of VV can be calculated using the principle of energy conservation, specifically the relationship between electric potential energy and kinetic energy.

When an electron is accelerated through a voltage VV, its kinetic energy becomes equal to the electric potential energy:

eV=12mv2eV = \frac{1}{2} mv^2

Where:

  • e=1.602×1019Ce = 1.602 \times 10^{-19} \, \text{C} (the charge of an electron),
  • m=9.109×1031kgm = 9.109 \times 10^{-31} \, \text{kg} (the mass of an electron),
  • V=50×103VV = 50 \times 10^3 \, \text{V} (the voltage through which the electron is accelerated),
  • vv is the final speed of the electron.

Now, we can solve for vv (the final speed of the electron):

v=2eVmv = \sqrt{\frac{2eV}{m}}

Substituting the known values:

v=2×(1.602×1019C)×(50×103V)9.109×1031kgv = \sqrt{\frac{2 \times (1.602 \times 10^{-19} \, \text{C}) \times (50 \times 10^3 \, \text{V})}{9.109 \times 10^{-31} \, \text{kg}}}

Let me calculate that.It seems there was a timeout error during the calculation. I'll guide you through solving it manually:

The equation we need to compute is:

v=2×(1.602×1019)×(50×103)9.109×1031v = \sqrt{\frac{2 \times (1.602 \times 10^{-19}) \times (50 \times 10^3)}{9.109 \times 10^{-31}}}

Step-by-step:

  1. Multiply the constants in the numerator: 2×(1.602×1019)×50×103=1.602×1014J2 \times (1.602 \times 10^{-19}) \times 50 \times 10^3 = 1.602 \times 10^{-14} \, \text{J}

  2. Divide by the electron mass: 1.602×10149.109×10311.759×1016\frac{1.602 \times 10^{-14}}{9.109 \times 10^{-31}} \approx 1.759 \times 10^{16}

  3. Take the square root: v=1.759×10164.2×108m/sv = \sqrt{1.759 \times 10^{16}} \approx 4.2 \times 10^8 \, \text{m/s}

Thus, the final speed of the electron is approximately 4.2×108m/s4.2 \times 10^8 \, \text{m/s}.

Would you like further details or clarifications?

Related Questions:

  1. How does increasing the voltage affect the speed of an electron?
  2. What would happen if the electron were replaced with a proton under the same conditions?
  3. How does the mass of a particle influence its acceleration through a given potential?
  4. What is the relationship between energy and voltage in this context?
  5. How does relativistic speed correction apply if the speed approaches the speed of light?

Tip: When calculating the speed of particles near light speed, consider relativistic effects for greater accuracy.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Energy Conservation
Kinetic Energy
Electric Potential Energy
Square Root Calculation

Formulas

eV = 1/2 mv^2
v = sqrt(2eV / m)

Theorems

Conservation of Energy

Suitable Grade Level

Grades 10-12