Review. In an electron microscope, there is an electron gun that contains two charged metallic plates 2.80 cm apart. An electric force accelerates each electron in the beam from rest to 9.60% of the speed of light over this distance. (a) Determine the kinetic energy of the electron as it leaves the electron gun. Electrons carry this energy to a phosphorescent viewing screen where the microscope’s image is formed, making it glow. For an electron passing between the plates in the electron gun, determine (b) the magnitude of the constant electric force acting on the electron, (c) the acceleration of the electron, and (d) the time interval the electron spends between the plates.
Review. In an electron microscope, there is an electron gun that contains two charged metallic plates 2.80 cm apart. An electric force accelerates each electron in the beam from rest to 9.60% of the speed of light over this distance. (a) Determine the kinetic energy of the electron as it leaves the electron gun. Electrons carry this energy to a phosphorescent viewing screen where the microscope’s image is formed, making it glow. For an electron passing between the plates in the electron gun, determine (b) the magnitude of the constant electric force acting on the electron, (c) the acceleration of the electron, and (d) the time interval the electron spends between the plates.
Solution Summary: The author calculates the kinetic energy of the electron in terms of speed of light using v=0.096c.
Review. In an electron microscope, there is an electron gun that contains two charged metallic plates 2.80 cm apart. An electric force accelerates each electron in the beam from rest to 9.60% of the speed of light over this distance. (a) Determine the kinetic energy of the electron as it leaves the electron gun. Electrons carry this energy to a phosphorescent viewing screen where the microscope’s image is formed, making it glow. For an electron passing between the plates in the electron gun, determine (b) the magnitude of the constant electric force acting on the electron, (c) the acceleration of the electron, and (d) the time interval the electron spends between the plates.
Definition Definition Rate at which light travels, measured in a vacuum. The speed of light is a universal physical constant used in many areas of physics, most commonly denoted by the letter c . The value of the speed of light c = 299,792,458 m/s, but for most of the calculations, the value of the speed of light is approximated as c = 3 x 10 8 m/s.
This transmission electron microscope (TEM) image of coronavirus can be taken using a beam of
electrons accelerated from rest through a potential difference of 25 kV. What is the final speed of
the electrons?
Provide the answer: .
x 108 m/s
The phenomenon where electrons are emitted from a material when it absorbs electromagnetic waves is called the photoelectric effect. Visible light shines energy on a metal sheet with energy enough for the metal sheet to emit electrons. In order to measure the energy of these electrons, another negatively charged plate (-24.8 V with respect to the metal sheet) is placed in the path of the electrons. The electrons slow down upon contact with the negatively charged plate and stop. What is the initial speed of these electrons?
Suppose an electron (q = - e = - 1.6 x 10¬19 C,m=9.1 × 10¬3' kg) is accelerated from rest through a potential
difference of Vab = +5000 V. Solve for the final speed of the electron. Express numerical answer in two significant figures.
The potential energy U is related to the electron charge (-e) and potential Vab is related by the equation:
U =
Assuming all potential energy U is converted to kinetic energy K,
K + U = 0
K = -U
mv and using the formula for potential energy above, we arrive at an equation for speed:
2
Since K=
v = (
1/2
Plugging in values, the value of the electron's speed is:
x 107 m/s
V=
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, physics and related others by exploring similar questions and additional content below.