An atom in an l=1 state emits a photon of wavelength 500.000 nm as it drops to an l=0 state when there is no external magnetic field.

a)Calculate the Zeeman effect splitting (in electron volts) between adjacent energy levels when this atom is placed in an external3.00-Tmagnetic field. (eV)

b) List the wavelengths of the 3 spectral lines that could be observed with a high-resolution spectrographas a result of the interaction of the atom with the B field. Hint: you may use |dE/E| = |dλ/λ|.Find λ1λ2λ3 in nm. Use 6 sig figs for each.

c) Draw an energy diagram showing the 3 different transitions responsible for λ1λ2 and λ

Problem 1. A particle is orbiting a star of mass M in a circular orbit. (a, 2 POINTS) Find the equation that provides the orbital speed at a given distance r from the center of the star. (b, 1 POINT) From the result at (a), calculate at what distance rS the particle should be from the center of the star for its orbital speed to be equal to the speed of light, c (in this case, the particle would be a photon). (c, 1 POINT) Calculate that distance, rS for a star of mass equal to M = 10M, where the mass of the Sun is M = 1.99 × 1030 kg and c = 2.997925 × 105 km/s. (d, 4 POINTS) If the particle is a star orbiting the Galaxy, find and plot the function that describes the speed of the star as a function of its distance from the center of the Galaxy, r. You must calculate this in two cases, if the star is inside or outside the Galaxy. Assume the Galaxy is a homogeneous sphere of maximum radius RGalaxy and density ρ0. (e, 2 POINTS) If the Sun is inside the Galaxy, its orbital speed is 220 km/s and its distance from the center is 25 × 1019 m, what is the mass in kilograms of the part of the Galaxy contained within the orbit of the Sun?

Light emitting diodes, lasers

1. Describe what physical property of a semiconductor will deem it good or bad for use in an LED.

2. Describe general operation and configuration of an LED, what determines the emission wavelength (color).

3. Describe the role of defects in emission in terms of an energy band diagram.

4. Define heterojunction, homojunction, epitaxy

5. Describe why lattice matching is important (broadly)

6. Describe why LED emission does not occur at a single wavelength, and how you expect this to change with temperature

7. Describe the general operation of a laser and the concept of population inversion

8. Describe why the linewidth of a laser is more narrow than that of a light emitting diode

1. Two devices that can be used to breakdown a spectrum into its components are the a. telescope and microscope

b. telescope and prism

c. diffraction grating and microscope d. prism and diffraction grating

2. The color cyan is made up of what two primary colors?

a. green and blue                   b. green and red

c. red and blue                       d. none of the above

3.

Using the chart above, what color/wavelength could the brain perceive if the eye sends the following code to the brain via the optic nerve?

Type I = 0      Type II = 14 Type III = 7

a. 500 nm                   b. 525 nm

c. 550 nm                   d. 575 nm

4. Which of the following colors is scattered the least in the atmosphere?

a. red

b. green c. blue

d. yellow

5.

The emission spectrum shown above could be for light produced by

a. an incandescent light bulb

b. the sun

c. hydrogen gas

d. a green LED

6. White objects appear white because they…

a. reflect all wavelengths of visible light equally

b. scatter light of all wavelengths in a 360 degree direction c. exhibit total internal reflection

d. absorb all wavelengths of visible light equally

7. Lemons appear yellow because they…

a. absorb red and green and scatter blue light.

b. absorb blue and scatter red and green light.

c. absorb blue and scatter yellow light.

d. absorb yellow and scatter red and green light.

8. A nearsighted person’s eyes

a) refract light too little and focus images of distant objects in front of the retina.

b) refract light too much and focus images of distant objects behind the retina.

c) refract light too much and focus images of distant objects in front of the retina.

d) have pupils that are too small.

9. At present, a compact disc can only hold about 1 hour of music. This limit is due in large part to the fact that

a) a compact disc cannot turn faster than about 5 turns per second without experiencing a net torque of zero.

b) light cannot be focused to a spot that is significantly smaller than its wavelength.

c) the ridges in the aluminum layer of the compact disc cannot experience destructive interference unless they have a wavelength that is almost equal to the distance between them.

d) a compact disc cannot turn slower than about 5 turns per second without experiencing a net torque of zero.

10. On average, how much sunlight is typically available on the ground of the Earth?

a) 171 Watts per sq. meter.

b) 1368 Watts per sq. meter

c) 174 Petawatts per sq. meter.

d) 11 Watts per sq. meter

PN Junctions and breakdown

1. Draw and interpret energy band diagram for pn junction in equilibrium, forward, and reverse bias

2. Describe what physically happens (And why) when you put n-Si in contact with p-Si (e.g., junction formation)

3. Calculate Vo, W, Wn, Wp

4. Describe how/why current flows in forward and reverse bias.

5. Utilize law of junction to calculate the minority carrier concentration just outside the depletion layer

6. Quantify the forward and reverse bias current in a p-n junction given appropriate information

7. Describe the meaning of the diode ideality factor for values of 1 and 2 and in between

8. Describe what constitutes “short diode” conditions

9. Calculate the depletion layer capacitance given sufficient information

10. Identify the two mechanisms that allow for reverse bias breakdown of a diode.

11. Describe what occurs during Zener tunneling and avalanche and the conditions that this will occur

Show And explain how the action integral and the planck constant have the same dimension and units.

In an aortic aneurysm, a bulge forms where the walls of the aorta are weakened. If blood flowing through the aorta (radius 1.1 cm) enters an aneurysm with a radius of 3.0 cm, how much on average is the blood pressure higher inside the aneurysm than the pressure in the unenlarged part of the aorta? The average flow rate through the aorta is 110 cm³/s. Assume the blood is non-viscous and the patient is lying down so there is no change in height.

Four protons are placed in the vertices of a square with a side of 2 x 10-9 m. A fifth proton
it is initially on the perpendicular to the square by its center, at a distance of 2 x 10-9 m from it. Calculate (a) the
minimum initial velocity that the fifth proton needs to reach the center of the square, (b) its initial and final accelerations.
(c) Make a graph of the proton's potential energy as a function of its distance to the center of the square.

Only two horizontal forces act on a 7.7 kg body. One force is 7.0 N, acting due east, and the other is 4.3 N, acting 40° north of west. What is the magnitude of the body's acceleration?

Three astronauts, propelled by jet backpacks, push and guide a 133 kg asteroid toward a processing dock, exerting the forces shown in the figure, with F₁ = 27 N, F₂ = 54 N, F₃ = 38 N, θ₁ = 30°, and θ₃ = 60°. What is the (a) magnitude and (b) angle (measured relative to the positive direction of the x axis in the range of (-180°, 180°]) of the asteroid's acceleration?

The figure shows a box of dirty money (mass m₁ = 4.5 kg) on a frictionless plane inclined at angle θ₁ = 23°. The box is connected via a cord of negligible mass to a box of laundered money (mass m₂ = 1.5 kg) on a frictionless plane inclined at angle θ₂ = 53°. The pulley is frictionless and has negligible mass. What is the tension in the cord?

. A lorry with mass 3500 kg is parked at the top of a steep hill with a 1–in–8 gradient when its handbrake fails. Assume that the lorry has a constant frictional resistance to motion of 500 N. The lorry rolls 40 m down the hill before crashing into a lamp post. Use the principle of conservation of energy to calculate the velocity of the lorry immediately prior to its impact with the lamp post.

When the air temperature is below 0 ?C, the water at the surface of a lake freezes to form a sheet of ice.

If the upper surface of an ice sheet 24.64cm thick is at -10.58?C and the bottom surface is at 0 ?C, calculate the time it will take to add 2.41mm to the thickness of this sheet.

ASTRONOMY for objects outside of the suns orbit. make an expression that converts the objects radial velocity and d (distance from the Sun). into angular speed and R. where r is the distance from the galactic center

Consider a system of five particles inside a container where the energy levels are evenly spaced. (For instance, the particles could be trapped in a one-dimensional harmonic oscillator potential.) In this problem, you will consider the allowed states for the system if the particles are identical fermions, identical bosons, or distinguishable particles.

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Consider these systems at a very high temperature. Speculate how the fermionic system, the bosonic system, and the distinguishable particle systems would differ, and support your stance with sound reasoning.

Online trolls drive us crazy saying that our cars are big, heavy and that they drive like boats. Well, our solution to everything is more horsepower. Even, in 1921, the Dodge Brothers built a boat named the SS Delphine and it had a whopping 3000 HP. So, how much horsepower would a Challenger SRT® Hellcat Redeye Widebody need to tow the SS Delphine up the industry standard: Davis Dam Grade Climb?

The video of the question on YouTube:

https://youtu.be/6JLrBj3dqvM

Pro Tips

Davis Dam assumed grade = 7%

Air density is sea level conditions (.002377 slugs/f^t3)

w(weight) of the SS Delphine + trailer + Redeye = 3,922,000 + 150,000 + 4451 Lbs

Crr = coefficient of rolling resistance = .015

Assume Combined CDA is 1555 ft^2

SAE J2807 (Davis Dam Grande Climb) - min speed is 40mpg (59 ft/s)

F(drag) = 1/2p x V^2 x C(d)A

F(rolling resistance) = W x cos x Crr

F(weight) = W x sin

F(sum) = F(drag) + F(rr) + F(weight)

P = F(sum)XV

convert to horsepower = P(1hp/550ft lbf/sec)