KE = kinetic energy of electron = 3 keV = 3 x 103 x 1.6 x 10-19 J = 4.8 x 10-16 J
p = momentum
m = mass of electron = 9.1 x 10-31 kg
Momentum is given as
p = sqrt(2 m (KE)) = sqrt(2 (9.1 x 10-31) (4.8 x 10-16)) = 2.96 x 10-23 kgm-s
p = uncertainty in momentum = 0.02 p = 0.02 x 2.96 x 10-23 = 5.92 x 10-25
x = uncertainty in position = ?
Using the equation
p x = h/(4)
(5.92 x 10-25) x = (6.63 x 10-34)/(4 x 3.14)
x = 8.92 x 10-11 m
1) The uncertainty in momentum of an electron with a kinetic energy of approximately 3 keV...
The position and momentum of a 3.01 keV electron are simultaneously determined. If its position is located to within 0.207 nm, what is the minimum percentage uncertainty in its momentum?
For a free electron with 100 keV kinetic energy, calculate the: a) electron speed b) electron momentum c) de Broglie wavelength of the electron
Calculate the momentum p, kinetic energy K, and total energy E of an electron traveling at each of the speeds tabulated below. v p (keV/c) K (keV) E (keV) (a) 0.02c (b) 0.1c (c) 0.6c
A) What is the speed of an electron with kinetic energy 780 eV ? B) What is the speed of an electron with kinetic energy 0.40 keV ?
h where ħ=__=1.054 x 10-34 Js 27 Uncertainty principle Question) Uncertainty in position of an electron is 1 nm. Estimate the minimum uncertainty in momentum and the corresponding kinetic energy.
An electron in a television picture tube has a classical kinetic energy of 78 keV, which is the kinetic energy that Newton would calculate using the measured speed and rest mass of the electron. What is the actual kinetic energy of the electron; that is, what is the value found using the relativistic result for the kinetic energy? (Give your answer in units of keV)
5) Consider an electron located on the x-axis such that the uncertainty in its position is 1.00 Angstrom. What is the minimum uncertainty in its momentum along the x axis? Give the answer in units of (kg m)/sec 6) If the work function of a metal is 2.00 x 10-19 J, what is the frequency of the light required to just eject an electron from the metal, that is, such that the ejected electron has zero kinetic energy? Give the...
3) A photon of energy 820 keV collides with an electron at rest. The photon eflects at an angle of 5o degrees. (a) Calculate the energy of the deflected photon. (b Calculate the kinetic energy of the electron after the collision. () Calculate the magnitude and direction of the electron momentum after the collision. (d) Calulate the wavelengths of the photon and electron after the collision.
The kinetic energy of an electron accelerated in an x-ray tube is 125 keV. Assuming it is nonrelativistic, what is its wavelength (in m)?
3) Suppose the instantaneous position of an electron of an electron moving along the x-axis is 10 A. The velocity of electron is 10sm/s. What is the minimum uncertainty in momentum? In velocity?, In kinetic energy? (Use your uncertainty relations)