Red light of wavelength 670 nm produces photoelectrons from a certain photoemissive material. Green light of wavelength 520 nm produces photoelectrons from the same material with 1.50 times the maximum kinetic energy. What is the material’s work function?

During a certain experiment, the de Broglie wavelength of an electron is $670 \mathrm{~nm}=6.7 \times 10^{-7} \mathrm{~m}$, which is the same as the wavelength of red light. How fast is the electron moving?

Red light $(\lambda=670.0 \mathrm{nm})$ produces photoelectrons from a certain material. Green light $(\lambda=520.0 \mathrm{nm})$ produces photoelectrons from the same material with 1.50 times the previous maximum kinetic energy. What is the material’s work function?

The photoelectric effect threshold wavelength for a certain metal is 400 nm. Calculate the maximum speed of photoelectrons if we use light having a wavelength of (a) 300 nm, (b) 400 nm, and (c) 500 nm.

A hydrogen atom is in its first excited state (n = 2). Using the Bohr theory of the atom, calculate the radius of the orbit.

Suppose a star with radius $8.50 \times 10 ^ { 8 }$ m has a peak wavelength of 685 nm in the spectrum of its emitted radiation. Find the energy of a photon with this wavelength.

A copper wire is 8.00 m long and has a cross-sectional area of $1.00 \times 10 ^ { - 4 } \mathrm { m } ^ { 2 }$. The wire forms a one-turn loop in the shape of square and is then connected to a battery that applies a potential difference of 0.100 V. If the loop is placed in a uniform magnetic field of magnitude 0.400 T, what is the maximum torque that can act on it? The resistivity of copper is $1.70 \times 10 ^ { - 8 } \Omega \cdot \mathrm { m }$.

A sodium surface is illuminated with 305 nm light. Determine the energy of each photon in joules.

State the instructions of the function in words.

$$\phi(s)=8-5x+s^2$$

The wave function of a quantum particle of mass m is

$$\psi(x)=A \cos (k x)+B \sin (k x)$$

where A, B, and k are constants. Find the corresponding energy E of the particle.

The wave function for a quantum particle is

$$\psi(x)=\sqrt{\frac{a}{\pi\left(x^{2}+a^{2}\right)}}$$

for a > 0 and $-\infty<x<+\infty .$ Determine the probability that the particle is located somewhere between x = -a and x = +a.

For the following statements, answer "true" or "false": If 0.04 is multiplied by 10, the product is a whole number.

As measured by an observer on the earth, a spacecraft runway on earth has a length of 3600 m.

What is the length of the runway as measured by a pilot of a spacecraft flying past at a speed of $4.00 \times 10^{7} \mathrm{m} / \mathrm{s}$ relative to the earth?

When light of wavelength 350 nm falls on a potassium surface, electrons having a maximum kinetic energy of 1.31 eV are emitted. Find the frequency corresponding to the cutoff wavelength.