Questions from Modern Physics

Q: In the Bohr model of the hydrogen atom, what is the

In the Bohr model of the hydrogen atom, what is the de Broglie wavelength of the electron when it is in a. the n = 1 level and b. the n = 4 level? In both cases, compare the de Broglie wavelength t...

Q: a. Write the Planck distribution law in terms of the frequency

a. Write the Planck distribution law in terms of the frequency f, rather than the wavelength λ, to obtain I(f). b. Show that where I(λ) is the Planck distribution formula...

Q: A beam of 40-eV electrons traveling in the +xdirection

A beam of 40-eV electrons traveling in the +xdirection passes through a slit that is parallel to the y-axis and 5.0 µm wide. The diffraction pattern is recorded on a screen 2.5 m from the...

Q: What is the de Broglie wavelength of a red blood cell,

What is the de Broglie wavelength of a red blood cell, with mass 1.00 * 10-11 g, that is moving with a speed of 0.400 cm/s? Do we need to be concerned with the wave nature of the blood cells when we d...

Q: High-speed electrons are used to probe the interior structure of

High-speed electrons are used to probe the interior structure of the atomic nucleus. For such electrons the expression l = h/p still holds, but we must use the relativistic expression for momentum, p...

Q: Suppose that the uncertainty of position of an electron is equal to

Suppose that the uncertainty of position of an electron is equal to the radius of the n = 1 Bohr orbit for hydrogen. Calculate the simultaneous minimum uncertainty of the corresponding momentum compon...

Q: The neutral pion (π0) is an unstable particle produced in

The neutral pion (π0) is an unstable particle produced in high-energy particle collisions. Its mass is about 264 times that of the electron, and it exists for an average lifetime of 8.4 * 10-17 s befo...

Q: To investigate the structure of extremely small objects, such as viruses

To investigate the structure of extremely small objects, such as viruses, the wavelength of the probing wave should be about one-tenth the size of the object for sharp images. But as the wavelength ge...

Q: Consider a particle with mass m moving in a potential U =

Consider a particle with mass m moving in a potential U = 1/2 kx2, as in a mass–spring system. The total energy of the particle is E =(p2/2m)+ 1/2 kx2. Assume that p and x are approximately related by...

Q: A pencil that is 9.0 cm long is held perpendicular

A pencil that is 9.0 cm long is held perpendicular to the surface of a plane mirror with the tip of the pencil lead 12.0 cm from the mirror surface and the end of the eraser 21.0 cm from the mirror su...