#  >> Standardized Tests >> MCAT

How to Calculate the Speed of an Electron

An electron is a fundamental particle that carries a negative charge. Although the charge it carries is equal and opposite to that of another important particle, the proton, it has only 0.05% of a proton's mass. Calculating the speed (or velocity) of an electron is important for solving many different physics and chemistry problems. The calculation and units may seem daunting to work with at first, but once simplified can be done with ease.

Things You'll Need

  • Scientific calculator
  • Scratch paper
  • Physics reference
Show More

Instructions

    • 1

      Determine the mass of a single electron, which is a constant value, and can be found in any good physics resource. The mass of one electron is 9.0 x 10^-31 kg.

    • 2
      Einstein's famous equation.

      Assume that your electron is starting at rest, therefore its energy (E) is equal to (1/2)mv^2.

    • 3

      Find the energy of your electron in joules. In this example, assume E=1 joule.

    • 4

      Write out the calculation and substitute your values: 1 joule = (1/2) * (9.0 x 10^-31 kg) * v^2.

    • 5

      Follow through with your calculation to find that your electron is moving at 9.5 x 10^-16 m/s.

Learnify Hub © www.0685.com All Rights Reserved