Can someone please explain to me how electromagnetic induction is used in Cochlear implants?

Conservation of Angular Momentum

A female figure skater is spinning on ice. Assume that that the surface is basically frictionless. The skater is wearing weighted bracelets as part of the costume for the performance. These weighted bracelets weight .75 kg each. The skater has a spinning routine in the middle of the performance and initially starts spinning with arms stretched wide such that the weighted bracelets are 1 m from the axis of rotation. She has an initial angular velocity of 2LaTeX: \pi π rad/s with an initial moment of inertia of 2.5 kg * m2. The skater then pulls her arms in towards her chest so that the weighted bracelets are just 10 cm from the axis of rotation as this will allow a faster spin, her moment of inertia drops to 2.1 kg * m2.

Part 1. What is the initial angular velocity of this skater. (answer should be a whole number)

rev/s

Part 2. What is the initial kinetic energy the skater has? (give your answer to the nearest J)

J

Part 3. What is the final angular velocity of this skater. (give your answer to 3 significant digits)

rev/s

Part 4. What is the final kinetic energy the skater has? (give your answer to the nearest J)

J

QUESTION 1

1. A disk (radius 13.5 cm] rotates about a fixed axis through its center of mass and perpendicular to the disk. At t = 0 the disk is rotating at frequency 6.64 Hz, and it accelerates uniformly to frequency 27.6 Hz after spinning through 60.4 revolutions. Find the angular acceleration of the disk, in rad/s².   

QUESTION 2

1. The wheel of a cart has radius 64.6 cm. How many revolutions will it make if the cart goes 6.45 km?

A block having a mass of0.72 kg is given an initial velocity v_A = 1.3 m/s to the right and collides with a spring whose mass is negligible and whose force constant is k = 45 N/m as shown in the figure.

The spring is now mounted vertically on the table, and the mass is dropped downwards, hitting the spring and compressing it. Just before the "collision", the block has a measured velocity of 2.00 m/s downwards. What will be the maximum compression of the spring? (Friction is negligible.)

Why T1 relaxation time is temperature dependent?

Why T2 relaxation time is temperature dependent?

Explain it with theory.

These are complete questions. If you don't understand the questions, you are not qualified to answer them.

Carlos and Shannon are sledding down a snow-covered slope that is angled at 12.0° below the horizontal. When sliding on snow, Carlos’s sled has a coefficient of friction μ_k = 0.100; Shannon has a “supersled” with μ_k = 0.0100. Carlos takes off down the slope starting from rest. When Carlos is 4.00 m from the starting point, Shannon starts down the slope from rest.

How far have they traveled when Shannon catches up to Carlos?

How fast is Shannon moving with respect to Carlos as she passes by?

(A) Young's double-slit experiment is performed with 560-nm light and a distance of 2.00 m between the slits and the screen. The tenth interference minimum is observed 7.30 mm from the central maximum. Determine the spacing of the slits (in mm).

(B) What If? What are the smallest and largest wavelengths of visible light that will also produce interference minima at this location? (Give your answers, in nm, to at least three significant figures. Assume the visible light spectrum ranges from 400 nm to 700 nm.)

smallest wavelength _______nm

largest wavelength________nm

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.