Problem 13:Suppose an alpha particle (which has a mass of 6.645 10^-27kg) is moving at0.19c.

Randomized Variables

v = 0.19 c

What is the momentum of the alpha particle in kg m/s?

Problem 14:The mass of an electron is 9.11 10^-31kg.

Part (a)Find the rest energy of an electron. Give your answer in joules.

Part (b)Find the rest energy of an electron. Give your answer in MeV.

Part B

Problem 1:Anti-reflective coatings on lenses use thin-film interference to eliminate the reflection of a particular color. Suppose a glass lens (n_g=1.6) is covered with a thin film (n_f=1.4) to prevent green light (=538nm) from being reflected.

Part (a)Write an expression for the minimum thickness the film can have, t.

Part (b)Calculate the minimum thickness, t, in nanometers?

Problem 3:Consider the perpendicular reflection of light of wavelength480nm in air from a soap film with refractive index1.37that has air on both sides.

Find the thickness, in nanometers, of the thinnest soap film that will cause constructive interference for the reflected light.

Problem 4:Light of wavelength489nm in air undergoes constructive interference when it is perpendicularly reflected from an oil spill on a plastic sheet. The refractive index of the oil is1.28and that of the plastic is1.44.

What is the nonzero thickness, in nanometers, of the thinnest oil film that causes such interference?

Problem 5:This question will ask what speed, expressed as a ratio to the speed of light, corresponds to various values of the relativistic parameter.

Part (a)At what speed, relative to the speed of light, is = 1.45?

Part (b)At what speed, relative to the speed of light, is = 100?

Problem 6:The dimensionless parameter is used frequently in relativity. As becomes larger and larger than 1, it means relativistic effects are becoming more and more important.

Part (a)What is if v = 0.24c?

Part (b)What is if v = 0.47c?