Suppose a friend is completing another physics assignment in their chair at their desk and you take the opportunity to turn this scenario into the physics question you now must complete. Your friend and chair have a combined constant moment of inertia of 4.6 kg m2, and the chair can freely rotate. Now your friend picks up two solid bricks (each of mass 1.4 kg) they accidentally collected from one of the campus buildings, and experiment with rotational kinematics. Supposing they hold the masses in each hand, arms outstretched, at distance of 0.7 m from their axis of rotation, and have an initial angular speed of 2.7 rev/s.

a) Calculate the distance in m of each brick from your friend’s axis of rotation if they pull the bricks inward such that their rotational speed has increased to 3.2 rev/s.

Answer: 0.396

b) What is the initial rotational kinetic energy of the system?

Answer: 21.76794

c) What is the final rotational kinetic energy of the system?

Answer: 25.79904

Could you please write down the full solution?

Two bars of equal proper length Lo approach each other, moving in a longitudinal direction parallel to a common axis with the same speed v with respect to a reference system of laboratory. What is the length of each of the bars in the reference system? linked with the other bar?

For 2 MeV alpha, beta, and gamma emissions calculate the following quantities relativistically for each emission: T (Kinetic Energy), E (total energy), gamma (correction factor), p (momentum), m (mass), and v (frequency). Use nuclear units, i.e., keV or MeV for energies, keV/c or MeV/c for momenta, MeV/c2 for masses and express velocities in units of c.

1) A car accelerates at 4 m /s / s. Assuming the car starts from rest, how far will it travel in 10 s?

2) An object falls freely from rest on a planet where the acceleration due to gravity is twice that of in Earth. Find the speed of the object after 5 second?

3) It takes 8 seconds for a stone to fall to the bottom of a mine shaft. How deep is the shaft?

4) A bag of groceries has a mass of 30 kilograms and in earth. Find its weight in the earth in moon?

5) If two force vector 20N and 40N are perpendicular to each other. Find the resultant vector?

a.Consider a hypothetical gas of four distinguishable particles, labeled W, X, Y and Z. Assume that they are distributed between only two translational quantum states of energies 2E and 4E. How many different configurations of this gas are there?

b.Consider a hypothetical gas of three distinguishable particles, labeled A, B and C. Each of the particles has only three quantum states of energies 5E, 10E and 15E. How many different configurations of this gas have a total energy of 30E?

c.Consider a hypothetical gas of three identical particles, each of which has only three quantum states of energies 3E, 6E and 9E. List all the different configurations of this gas that have a total energy of 18E assuming that the particles are (i) identical bosons and (ii) identical fermions.

d.Consider a hypothetical gas of four identical bosons, each of which has only four quantum states of energies E, 2E, 3E and 4E. Suppose the total energy of the gas is fixed at 12E. Determine the probability of finding all four particles in the same quantum state.

A Geiger tube consists of two elements, a long metal cylindrical shell and a long straight metal wire running down its central axis. Model the tube as if both the wire and cylinder are infinitely long. The central wire is positively charged and the outer cylinder is negatively charged. The potential difference between the wire and the cylinder is 1.10 kV. Suppose the cylinder in the Geiger tube has an inside diameter of 3.64 cm and the wire has a diameter of 0.452 mm. The cylinder is grounded so its potential is equal to zero.

(a) What is the radius of the equipotential surface that has a potential equal to 545 V? Is this surface closer to the wire or to the cylinder?

(b) How far apart are the equipotential surfaces that have potentials of 195 and 245 V?

(c) Compare your result in Part (b) to the distance between the two surfaces that have potentials of 685 and 730 V, respectively.

What does this comparison tell you about the electric field strength as a function of the distance from the central wire?

If n₁<n₂ and n₃<n₂, which of the following statements are true when it comes to finding out if you have destructive interference of the reflected rays?

You do need to know if n₁ is bigger or smaller than n₃.

You cannot make any calculations unless you know the numerical value of n₃.

You cannot make any calculations unless you know the numerical value of n₂.

The reflected ray from the interface between medium 1 and medium 2 will undergo a different phase change than the ray reflected from the interface between 2 and 3.

You cannot make any calculations unless you know the numerical value of the thickness of layer 2.

You cannot make any calculations unless you know the numerical value of n₁.

For 2 MeV alpha, beta, and gamma emissions calculate the following quantities relativistically for each emission: T (Kinetic Energy), E (total energy), gamma (correction factor), p (momentum), m (mass), and v (frequency). Use “nuclear units,” i.e., keV or MeV for energies, keV/c or MeV/c for momenta, MeV/c2 for masses and express velocities in units of c.

A commercial refrigerant that uses R-134a as the refrigerant is used for cooling, to keep the condition at -35o, throws heat into the cooling water that has been in the condenser at 18oC and 0.25kg / s and has been formed since 26o. The refrigerant enters the condenser at 1.2 MPa and 50o ° and exits by cooling 5o C more than the saturation temperature at the same pressure. If the compressor consumes 3.3 kW (Answer: 0.0498 kg / s, 5.07 kW, 1.54, 1.13 kW) a) mass flow rate of refrigerant b) cooling load (amount of usage amount of heat) c) COP d) required for the same cooling load tr detect small compressor power

1. What is the working principle of a photodiode? Give three examples of photodiodes’ real-life applications.

2. Which of the following photodiode modes performs better in saturation and response time? Photovoltaic or photoconductive mode? Explain the physics behind your answers.

How much work, in Joules, does it take to dig up a cylindrically shaped hole of depth 2 meters and outer diameter 3 meters? How many servings of pasta are required to complete this work, assuming the energy from the pasta is converted with 5% efficiency to work? Assume that one serving of pasta contains 200 Cal, and the density of soil is 1,200 kg/m3.

1. Why are the thermal detectors slower and less sensitive than the photon detectors?

2. What are the physical origins of the shot noise and Johnson noise in an optical detector?

Stars fuse lighter nuclei to form heavier nuclei (to the extent that they are capable and the fusion process is energetically favorable). Based on the plot of binding energy per nucleon, do you expect to see fusion of uranium atoms in a star? Why/why not?

Suppose two worlds, each having mass M and radius R, coalesce into a single world. Due to gravitational contraction, the combined world has a radius of only 7/8 R. What is the average density of the combined world as a multiple of ρ0, the average density of the original two worlds?

Two copper plates 0.50cm thick have a 0.10mm sheet of glass sandwiched between them. One copper plate is kept in contact with flowing ice water and the other is in contact with stream. What are the temperatures of the two copper-glass interfaces, and what is the power transferred through a 10cm by 10cm area? kcopper=385 K/mC and kglass=0.8 K/mC

The answers given are: 9C, 91 C, and 6.6E3 W. I am just trying to learn the process of solving problems like this and my closest answer was 7837 W, which is still off.