Questions from College Physics

Q: The radius of our Sun is 6.96 x 108 m

The radius of our Sun is 6.96 x 108 m, and its total power output is 3.85 x 1026 W. (a) Assuming the Sun’s surface emits as a blackbody, calculate its surface temperature. (b) Using the result of part...

Q: Earth’s average surface temperature is about 287 K. Assuming Earth radiates

Earth’s average surface temperature is about 287 K. Assuming Earth radiates as a blackbody, calculate λmax for the Earth.

Q: Suppose a star with radius 8.50 x 108 m has

Suppose a star with radius 8.50 x 108 m has a peak wavelength of 685 nm in the spectrum of its emitted radiation. (a) Find the energy of a photon with this wavelength. (b) What is the surface temperat...

Q: Calculate the energy, in electron volts, of a photon whose

Calculate the energy, in electron volts, of a photon whose frequency is (a) 6.20 x 102 THz, (b) 3.10 GHz, and (c) 46.0 MHz.

Q: The threshold of dark - adapted (scotopic) vision is 4

The threshold of dark - adapted (scotopic) vision is 4.0 x 10-11 W/m2 at a central wavelength of 5.00 x 102 nm. If light with this intensity and wavelength enters the eye when the pupil is open to its...

Q: Monochromatic light falls on a screen 1.75 m from two

Monochromatic light falls on a screen 1.75 m from two slits separated by 2.10 mm. The first - and second - order bright fringes are separated by 0.552 mm. What is the wavelength of the light?

Q: When light of wavelength 3.50 x 102 nm falls on

When light of wavelength 3.50 x 102 nm falls on a potassium surface, electrons having a maximum kinetic energy of 1.31 eV are emitted. Find (a) The work function of potassium, (b) The cutoff wavelengt...

Q: The work function for zinc is 4.31 eV.

The work function for zinc is 4.31 eV. (a) Find the cutoff wavelength for zinc. (b) What is the lowest frequency of light incident on zinc that releases photoelectrons from its surface? (c) If photons...

Q: The work function for platinum is 6.35 eV.

The work function for platinum is 6.35 eV. (a) Convert the value of the work function from electron volts to joules. (b) Find the cutoff frequency for platinum. (c) What maximum wavelength of light in...

Q: Lithium, beryllium, and mercury have work functions of 2.

Lithium, beryllium, and mercury have work functions of 2.30 eV, 3.90 eV, and 4.50 eV, respectively. Light with a wavelength of 4.00 x 102 nm is incident on each of these metals. (a) Which of these met...