Figure 1: Figure 2: Figure 3: Figure 4: Part A The electric and magnetic field vectors at a specific point in space and time are illustrated. (Figure 1) Based on this information, in what direction does the electromagnetic wave propagate? Part B The electric and magnetic field vectors at a specific point in space and […]

## Problem 25.37

Only 20 % of the intensity of a polarized light wave passes through a polarizing filter. Part A What is the angle between the electric field and the axis of the filter? Express your answer using two significant figures.

## Problem 28.46

Part A What is the linear size of the smallest box in which you can confine an electron if you want to know for certain that the electron’s speed is no more than 22 m/s ? Express your answer to two significant figures and include the appropriate units.

## Problem 28.42

The allowed energies of a quantum system are 0.0 eV, 5.5 eV , and 8.5 eV. Part A What wavelengths appear in the system’s emission spectrum? Enter your answers in ascending order separated by commas.

## Problem 28.36

Part A What is the length of a box in which the minimum energy of an electron is 1.3×10−18 J ?

## Problem 28.34

Rubidium atoms are cooled to 0.12 μK in an atom trap. Part A What is their de Broglie wavelength? Express your answer with the appropriate units. Part B How many times larger is this than the 0.25 nm diameter of the atoms?

## Problem 28.30

Part A What is the speed of an electron with a de Broglie wavelength of 0.19 nm ? Part B What is the speed of a proton with a de Broglie wavelength of 0.19 nm ?

## Problem 28.26

Dinoflagellates are single-cell creatures that float in the world’s oceans; many types are bioluminescent. When disturbed by motion in the water, a typical bioluminescent dinoflagellate emits 100,000,000 photons in a 0.10 s long flash of light of wavelength 460 nm. Part A What is the power of the flash in watts? Express your answer using […]

## Problem 28.18

A firefly glows by the direct conversion of chemical energy to light. The light emitted by a firefly has peak intensity at a wavelength of 550 nm. Part A What is the minimum chemical energy, in eV, required to generate each photon? Express your answer using three significant figures. Part B One molecule of ATP […]

## Problem 28.14

Image intensifiers used in night-vision devices create a bright image from dim light by letting the light first fall on a photocathode. Electrons emitted by the photoelectric effect are accelerated and then strike a phosphorescent screen, causing it to glow more brightly than the original scene. Recent devices are sensitive to wavelengths as long as […]