# Homework 10 (Due 4/29/16)

- Page ID
- 47385

Name: ______________________________

Section: _____________________________

Student ID#:__________________________

### Q10.1

What is the wavelength associated with a photon of a light with the energy is 3.6x10^{-19}J?

### Q10.2

Calculate the energy of a photon of a light with the frequency is 6.5x10^{-14} s^{-1 }?

### Q10.3

Rigel is the brightest star in the constellation Orion and the seventh brightest star in the night sky. Rigel has an emission spectrum that peaks at ~145 nm. What is the surface temperature of Rigel? How does this temperatures compare with our sun (you have to look this up)?

### Q10.4

Find the longest-wavelength photon that can eject an electron from potassium, given that the work function is 2.24 eV. Is this visible electromagnetic radiation?

### Q10.5

A laser with a power output of 2.00 mW at a wavelength of 400 nm is projected onto calcium metal. (a) How many electrons per second are ejected? (b) What power is carried away by the electrons, given that the work function is 2.71 eV?

### Q10.6

What is the longest-wavelength electromagnetic radiation that can eject a photoelectron from silver, given that the work function is 4.73 eV? Is this in the visible range?