Question

the rest mass of an electron 9.11 into 10 to the power minus 31 kg the mass of an electron is ​

Answer 1

Answer:

Answer:

We cleared the velocity of the equation of the relativistic mass

v = c √(1 – (m0 / mr)2

Now we replace the data

v = (3.00 x 108 m/s) √(1 – 9.11 x 10-31 kg / 12.55 x 10-31 kg)

v = 2.06 x 108 m/s

2) The rest mass of an electron is 9.1 x 10-31 kg and it moves with a speed of 4.5 x 105 m/s. Calculate the relativistic mass.

Answer 2

Answer:

Explanation:

The De Broglie wavelength equation is as follows:

λ=h/p

We know the value of Planck's constant h and so to calculate the wavelength all we need is the momentum, which is equal to mv.

The kinetic energy is given as 1 eV. Remember 1 eV is equal to 1.6 x 10-19 Joules. Using the equation for kinetic energy and the given mass of the electron we can determine the velocity of the electron as follows:

K.E = 0.5mv2

Which can be rearranged to be in terms of velocity v:

v = (2K.Em)0.5

By substituting in 1.6 x 10-19 for K.E and 9.11 x 10-31 for m we get v = 5.93 x 105 ms-1 (remember to keep the full non-rounded value in your calculator!)

Then using the initial equation for the wavelength and remembering p = mv, we can substitute in our values for h, m and v as follows:

λ = 6.33 x 10-34 / (9.11 x 10-31 x 5.93 x 105)

λ = 1.17 x 10-9 m

Hope it helps you...