Horizontal rays of red light (λ = 660 nm, in vacuum) and violet light (λ = 410 nm, in vacuum) are incident on the flint-glass prism shown in the drawing. The indices of refraction for the red and violet light are n_red = 1.662 and n_violet = 1.698. The prism is surrounded by air. What is the angle of refraction for (a) red ray, (b) violet ray as it emerges from the prism?

A certain brand of freezer is advertised to use 685 kW · h of energy per year. (a) Assuming the freezer operates for 4.5 hours each day, how much power does it require while operating? W (b) If the freezer keeps its interior at a temperature of −9.5°C in a 21.4°C room, what is its theoretical maximum performance coefficient? (c) What is the theoretical maximum amount of ice this freezer could make in an hour, starting with water at 21.4°C?

1. Give two examples of forces you exerted on objects today. What factors were different about each force you mentioned?

2. How do you calculate the net force of an object?

3. What is the difference between a balanced and unbalanced force? Provide an example of each.

4. True or False? Inertia is a force.

5. True or False? The net force of a balanced force is 0.

6. The more mass an object has, the ____________ inertia it has.

7. Using the picture below answer the question: What is the net force? In what direction is the car going to move?

Since force is m*a, it has units of kg m/s^2 . Energy has units of kg m^2/s^2. Thus it appears that by lazy dimensional analysis that a force times a distance will have units of energy. This turns out to be the formula to calculate work. Note also that kg m^2/s^2 looks like mv^2. Here if we use dimensional analysis, we would *almost* find the formula for kinetic energy. We'd be off by a factor of two since KE=1/2 mv^2. Note that this would still be useful for estimation (such as we did the first few weeks).

1) Describe Bohr’s quantum model of the atom.

2) Derive expressions for the energies and radii of an electron in the hydrogen atom.

3) Discuss experiments that confirmed the existence of quantized atomic energy levels.

My physics class did an online lab thing where a charged plastic rod is brought near a magnetic and non-magnetic conduction rod about the same size. Both ends of the magnet and the non-magnetic rod were attracted to the charged rod. I am a little confused and what forces/ different forces are causing this

Question: If the charged rod is attracted to the magnetic and the non-magnetic rod in the same way, can you conclude that there are any special interactions or forces between either of the magnetic poles and the rod?

Question: Is the interaction between magnets a different phenomenon from the electrostatic interaction of charges? Cite evidence for your answer (use question 2 to help). Keep in mind we are talking about electrostatics i.e. the charges are not moving, NOT electrodynamics where charges are in motion.

Find the net torque on the wheel in the figure below about the axle through O perpendicular to the page, taking a = 5.00 cm and b = 23.0 cm. (Indicate the direction with the sign of your answer. Assume that the positive direction is counterclockwise.) N · m A wheel rotating about an axle is approximated as two concentric circles with the center defined to be O. The radius of the inner circle is a and the radius of the outer circle is b. Three arrows representing individual forces are as follows. An arrow labeled 12.0 N acts on the top left of the inner circle, and points down and to the left at an angle of 30.0° below the horizontal. An arrow labeled 10.0 N acts on the top of the outer circle and points to the right. An arrow labeled 9.00 N acts on the right of the outer circle and points down.

To find the height of an overhead power line, you throw a ball straight upward. The ball passes the line on the way up after 0.85 s , and passes it again on the way down 1.5 s after it was tossed.

a) What is the height of the power line?

b) What is the initial speed of the ball?

Refractive index of core of an optical fibre is 1.46 and its diameter is 250μm. Light propagates along the axis of the fibre . If the fibre bends at one point with radius of curvature R, Calculate the minimum value (critical radius of curvature R_min) to sustain the light inside, without escaping from the fibre.

Discuss the factors on which the critical radius of curvature may depend? Does it depend on the colour of light propagating through the fibre?   

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6. Electromagnetism

a. Describe two ways to increase the strength of an electromagnet

b. Write two or three sentences to identify the energy conversion that takes place in an electric motor and to describe how electromagnetism is involved.

c. Write two or three sentences to compare the primary and secondary coils in a step-down transformer and to explain how electromagnetism is involved in its function.

d. What is the magnetic force on a particle that has -3.2 x 10^-19 C of charge and is moving at 2.5 x 10^7 m/s to the right through a magnetic field that is 0.24 T and pointing away from you? Specify both magnitude and direction in your answer.

1.Explain how a solenoid works - how does it produce a magnetic field?

2. What are the five major types of magnetic materials? Describe each briefly.

A metal marble is launched with a speed of v0 = 30.0m/s at 5.0 ◦ relative to the horizontal, from a height of 1.0 m above ground, and towards a very tall vertical wall, which is 6.0 m away from the launch position. The projectile may first hit the wall, or the ground. Whichever it turns out to be, assume that this is an elastic, specular collision, so that the projectile bounces off. After some time, the projectile will have another collision, which again could be either with the ground or with the wall.

Find: (a) the location of the second collision; (b) the highest point (both the x- and the y-coordinates) that the projectile reaches between its launch and the second collision; (c) the velocity (the magnitude and the angle relative to the vertical—make a sketch so that it is clear which angle you are reporting) 0.50 s after launch.

A sample of radioactive materials emits 1 MeV gamma rays and has an activity of 23 curies, How long can a radiation worker be exposed to the affected area before exceeding the annual exposure limit of 5 rem? The worker is in direct contact with the sample.

A car is parked on the side of the road with the radio playing. Physics students in the car measure the sound coming from the radio to be 18.2 kHz. Another physics student is riding a bike and moving towards the car at 30 km/h.

a) What is the frequency of the radio as heard by the physics student riding the bike?

b) The physics student riding the bike passes the car and starts to move away from the car. What now, is the frequency of the radio as heard by the physics student riding the bike?

Please help me with this.