1. AP Physics Monday 14.04.28 Homework W#3 Warm Up If a double slit experiment was done using a 450 nm laser, while shining through two slits of 1cm and projected on a screen 1 m away, how far away from the central maximum would the first bright spot be? How far would the 3 rd be? Draw the diagram. Agenda 1.Warm Up 2.Review & Collect HW 3.Snell’s Law/ Reflection & Refraction 4.W#3 Standards: C Geometric Optics 1 Reflection & Refraction a. Use snell’s law to relate the directions of the incident & refracted ray. Objective: SWBAT use snell’s law to solve problems involving light changing mediums.

2. Agenda 1.Warm Up 2.Finish Refraction 3.Mirrors & Lenses Demonstration 4.Mirrors and Lenses Notes Warm Up A 550nm light wave travels in glass (n=1.52) with an incident angle of 33° then the light wave changes mediums and goes into water (n=1.33). Find the speed of light in glass. Find the speed of light in water. Find the angle of refraction as the light goes into the water. Homework W#4 AP Physics Tuesday 14.04.29 Standards: C. Geometric Optics, 2,3 mirrors & lenses a-d Objective: SWBAT trace ray diagrams and find the images on different lenses.

3. AP Physics Wednesday 14.04.30 Agenda 1.Warm Up 2.Review HW 3.Questions About Lenses & Mirrors 4.Photoelectric Effect & Compton Scattering. Homework M&N#1 Warm Up An object with a height (h o ) is in 4 m in front of a converging lens with a 3 m focal length. Find the location and magnification of the image using calculations & by drawing the 3 ray diagram. Standards: VA1 Photoelectric Effect, Compton Scattering Objective: SWBAT understand the physics behind the photoelectric effect and compton scattering. f f 4m 3m

4. AP Physics Thursday 14.05.01 Homework M&N 2 Warm Up A photon with a wavelength of 450 nm hits a photosensitive material and knocks out an electron, causing 2V of current to flow through a wire. Find out how much work it takes for the light to eject the electron (work function). Agenda 1.Warm Up 2.Review HW 3.Compton Effect 4.Bohr Atom, 5.Wave/Particle Duality. 6.M&N 2 Standards: VA. c. understand compton scattering, bohr atom, wave/particle duality Objective: SWBAT be able to solve AP problems in Atomic Physics step 1: E=hf, c=fλ find energy step 2: K max =V o e (Voltage =energy/charge step 3: E photon =K max electron + ϕ o conservation of energy

5. AP Physics Friday 14.05.02 Homework M&N #3 Warm Up An electron in a Hydrogen Atom makes a transition from the 4 th excited state to the ground state. How much energy did it radiate & what was the wavelength of the radiated photon. Agenda 1.Warm Up 2.Review HW 3.Matter Waves 4.Nuclear Reactions 5.Energy from Nuclear Reactions 6.M&N #3 Standards: VA3 Wave-particle duality, VB1 Nuclear Reaction, VB2 Mass/Energy Equivalence Objective: SWBAT prepare for the AP Physics Test

6. W#3 Refraction of Light 2000B4. A sheet of glass has an index of refraction ng = 1.50. Assume that the index of refraction for air is n a = 1.00. a. Monochromatic light is incident on the glass sheet, as shown in the figure below, at an angle of incidence of 60°. On the figure, sketch the path the light takes the first time it strikes each of the two parallel surfaces. Calculate and label the size of each angle (in degrees) on the figure, including angles of incidence, reflection, and refraction at each of the two parallel surfaces shown. b. Next a thin film of material is to be tested on the glass sheet for use in making reflective coatings. The film has an index of refraction n f = 1.38. White light is incident normal to the surface of the film as shown below. It is observed that at a point where the light is incident on the film, light reflected from the surface appears green (λ = 525 nm). i. What is the frequency of the green light in air? ii. What is the frequency of the green light in the film? iii. What is the wavelength of the green light in the film? iv. Calculate the minimum thickness of film that would produce this green reflection.

7. W#4 Geometric Optics 1974B3. An object 1 centimeter high is placed 4 centimeters away from a converging lens having a focal length of 3 centimeters. (a) Sketch a principal ray diagram for this situation. (b) Find the location of the image by a numerical calculation. (c) Determine the size of the image. 1978B5. An object 6 centimeters high is placed 30 centimeters from a concave mirror of focal length 10 centimeters as shown above. (a) On the diagram above, locate the image by tracing two rays that begin at point P and pass through the focal point F. Is the image real or virtual? Is it located to the left or to the right of the mirror? (b) Calculate the position of the image. (c) Calculate the size of the image. (d) Indicate on the diagram above how the ray from point P to point Q is reflected, if aberrations are negligible.

8. M&N #1 1983B6. An experiment is conducted to investigate the photoelectric effect. When light of frequency 1.0 x 10 15 hertz is incident on a photocathode, electrons are emitted. Current due to these electrons can be cut off with a 1.0-volt retarding potential. Light of frequency 1.5 x 10 15 hertz produces a photoelectric current that can be a. Calculate an experimental value of Planck's constant based on these data. cut off with a 3.0-volt retarding potential. b. Calculate the work function of the photocathode. c. Will electrons be emitted from the photocathode when green light of wavelength 5.0 x 10 –7 meter is incident on the photocathode? Justify your answer.

9. M&N #2 1985B6. An energy-level diagram for a hypothetical atom is shown above. a. Determine the frequency of the lowest energy photon that could ionize the atom, initially in its ground state. b. Assume the atom has been excited to the state at -1.0 electron volt. (Electron volt is energy, charge of electron x voltage. Mr.A) i. Determine the wavelength of the photon for each possible spontaneous transition. ii. Which, if any, of these wavelengths are in the visible range? c. Assume the atom is initially in the ground state. Show on the following diagram the possible transitions from the ground state when the atom is irradiated with electromagnetic radiation of wavelengths ranging continuously from 2.5 x 10 –7 meter to 10.0 x 10 –7 meter.

10. M&N #3 1991B6. Light consisting of two wavelengths, λ a = 4.4 x 10-7 meter and λ b = 5.5 x 10-7 meter, is incident normally on a barrier with two slits separated by a distance d. The intensity distribution is measured along a plane that is a distance L = 0.85 meter from the slits as shown above. The movable detector contains a photoelectric cell whose position y is measured from the central maximum. The first-order maximum for the longer wavelength λ b occurs at y = 1.2 x 10 -2 a. Determine the slit separation d. meter. b. At what position Y a does the first-order maximum occur for the shorter wavelength λ a ? In a different experiment, light containing many wavelengths is incident on the slits. It is found that the photosensitive surface in the detector is insensitive to light with wavelengths longer than 6.0 x 10 -7 m c. Determine the work function of the photosensitive surface. d. Determine the maximum kinetic energy of electrons ejected from the photosensitive surface when exposed. to light of wavelength λ = 4.4 x 10 -7 m.

11. M&N#4 1993B6. In the x-ray tube shown above, a potential difference of 70,000 volts is applied across the two electrodes. Electrons emitted from the cathode are accelerated to the anode, where x-rays are produced. a. Determine the maximum frequency of the x-rays produced by the tube. b. Determine the maximum momentum of the x-ray photons produced by the tube. An x-ray photon of the maximum energy produced by this tube leaves the tube and collides elastically with an electron at rest. As a result, the electron recoils and the x-ray is scattered, as shown above. The frequency of the scattered x-ray photon is 1.64 x 1019 hertz. c. Determine the kinetic energy of the recoiled electron. d. Determine the magnitude of the momentum of the recoiled electron. e. Determine the deBroglie wavelength of the electron

12. M&N#5 1989B6. A lithium nucleus, while at rest, decays into a helium nucleus of rest mass 6.6483 x 10–27 kilogram and a proton of rest mass 1.6726 x 10 –27 kilogram, as shown by the following reaction. In this reaction, momentum and total energy are conserved. After the decay, the proton moves with a speed of 1.95 x 10 7 m/s. a. Determine the kinetic energy of the proton. b. Determine the speed of the helium nucleus. c. Determine the kinetic energy of the helium nucleus. d. Determine the mass that is transformed into kinetic energy in this decay. e. Determine the rest mass of the lithium nucleus. B2007B7. In the vicinity of a heavy nucleus, a high-energy photon can be converted into two particles: an electron and a positron. A positron has the same mass as the electron and equal but opposite charge. This process is called pair production. (a) Calculate the rest energy of an electron, in eV. (b) Determine the minimum energy, in eV, that a photon must have to give rise to pair production. (c) Calculate the wavelength corresponding to the photon energy found in part (b). (d) Calculate the momentum of the photon.