A mass is placed on a frictionless, horizontal table. A spring ( k = 185 k=185 N/m), which can be stretched or compressed, is placed on the table. A 4.5-kg mass is anchored to the wall. The equilibrium position is marked at zero. A student moves the mass out to x = 7.0 x=7.0 cm and releases it from rest. The mass oscillates in simple harmonic motion. Find the position, velocity, and acceleration of the mass at time t = 3.00 t=3.00 s. Round all of your answers to one decimal place.

In a nuclear fission reactor, each fission of a uranium nucleus is accompanied by the emission of one or more highspeed neutrons, which travel through the surrounding material. If one of these neutrons is captured in another uranium nucleus, it can trigger fission, which produces more fast neutrons, which could make possible a chain reaction. However, fast neutrons have low probability of capture and usually scatter off uranium nuclei without triggering fission. In order to sustain a chain reaction, the fast neutrons must be slowed down in some material, called a “moderator.” For reasons having to do with the details of nuclear physics, slow neutrons have a high probability of being captured by uranium nuclei.

A slow neutron induces fission of U-235, with the emission of additional (fast) neutrons. The moderator is some material that slows down the fast neutrons, enabling a chain reaction.

In the following analyses, remember that neutrons have almost no interaction with electrons. Neutrons do, however, interact strongly with nuclei, either by scattering or by being captured and made part of the nucleus. Therefore you should think about neutrons interacting with nuclei (through the strong force), not with entire atoms.

1. Based on what you now know about collisions, explain why fast neutrons moving through a block of uranium experience little change in speed.

2. Explain why carbon should be a much better moderator of fast neutrons than uranium.

3. Should water be a better or worse moderator of fast neutrons than carbon? Explain briefly.

A transverse sinusoidal wave is generated at one end of a long, horizontal string by a bar that moves up and down through a distance of 1.7 cm. The motion is continuous and is repeated regularly 160 times per second. The string has linear density 460 g/m and is kept under a tension of 140 N. Find the maximum value of (a) the transverse speed u and (b) the transverse component of the tension T. (c)Show that the two maximum values calculated above occur at the same phase values for the wave. What is the transverse displacement y of the string at these phases? (d) What is the maximum rate of energy transfer along the string? (e) What is the transverse displacement y when this maximum transfer occurs? (f ) What is the minimum rate of energy transfer along the string? (g) What is the transverse displacement y when this minimum transfer occurs?

A.)

In the lab, you will determine a value for the time constant of the RC circuit, by measuring the amount of time it takes the capacitor voltage to increase from 0.0 V to ______ % of its maximum value.

B.)

If you only have capacitors of one value, you can change the total capacitance of the circuit by using combinations of capacitors. Assuming that all the capacitors have the same value, how could you increase the total capacitance?

Options:

B) A 1300 -kg car is pushing an out-of-gear 2200 -kgtruck that has a dead battery. When the driver steps on the accelerator, the drive wheels of the car push horizontally against the ground with a force of 4500 N . The rolling friction of the car can be neglected, but the heavier truck has a rolling friction of 760 N , including the "friction" of turning the truck's drivetrain. What is the acceleration aT of the truck?

C) An 89.0 kg spacewalking astronaut pushes off a 620 kg satellite, exerting a 85.0 N force for the 0.540 s it takes him to straighten his arms. How far apart are the astronaut and the satellite after 1.50 min ?

A microscope has an object lens f=11 mm and an eyepiece lens f=22 mm separated by 122 mm. Where is the image of the eyepiece located? What is the magnification?

Can you give 2 othere examples of a diagnostic radiopharmaceutical, there uses and desirable radiological and biological properties.

e.g - sodium pertechetiate 99m (please don't pick this one again);

Under electrostatic condition electric charge Q = 17.7x10-9 C is uniformly distributed on the surface of an isolated conducting sphere of radius R = 3 m. There is no other charge around. (a) What is the electric flux through a concentric spherical surface of radius 2R. (b) What is the electric potential at the surface of the conducting sphere? What is the electric field inside the conducting sphere? Please explain the steps and formuals .Mandatory !!

The temperature in Winterberg is a sinusoidal function in time. 120 days ago, the temperature was at its maximum value of 55◦F. The tempearture has been falling since then, and 20 days from today it will reach its minimum value of 10◦F.

(a) Write a function f(t) in sinusoidal standard form for the temperature in Winterberg, in Fahrenheit, t days from today

b)People can only ski when the temperature is below 28◦F. Over the next 700 days (starting today), for how many days is it cold enough to ski? You can round all your answers to the nearest day.

A positive charge q is fixed at the point x=0,y=0 and a negative charge -2q is fixed at the point x=a,y=0.

Part A:

Derive an expression for the potential V at points on the y-axis as a function of the coordinate y. Take V to be zero at an infinite distance from the charges.

Part B:

At which positions on the y-axis is V = 0?

Part C:

What does the answer to part A become when y>>a?

Part D:

Explain why this result is obtained.

A parallel plate capacitor with plate separation d is connected to a battery. The capacitor is fully charged to Q Coulombs and a voltage of V. (C is the capacitance and U is the stored energy.) Answer the following questions regarding the capacitor charged by a battery. For each statement below, select True or False.

After being disconnected from the battery, inserting a dielectric with κ will increase U.
With the capacitor connected to the battery, decreasing d increases U.
With the capacitor connected to the battery, inserting a dielectric with κ will increase C.
With the capacitor connected to the battery, increasing d increases C.
After being disconnected from the battery, increasing d decreases V.
After being disconnected from the battery, inserting a dielectric with κ will decrease V.

We did an experiment : determination of entropy changes during melting of ice in a closed system. Can you write a 400 words paragraph introduction about The Second Law of Thermodynamics, entropy, entropy changes in reversible and irreversible processes, methods of calculating entropy changes in isothermal, isobaric and isochoric processes and entropy of the phase transformation.

In your own words. No copy-paste from the internet. Pleasee!!

In forensic science, it is useful to measure the speed at which firearms propel bullets. Before modern instruments, this was done with a device called a “ballistic pendulum”, consisting of a block of some soft material hanging from the end of a string. The experimenter fires a bullet into the block, which lodges into it; the block swings up at an angle. By measuring the angle, the experimenter can determine the velocity of the bullet.

Suppose that you are a detective trying to measure the velocity of the bullets fired from a particular gun. You construct a ballistic pendulum out of a string of length 50 cm and a clay block of mass 2 kg, and fire a bullet into it. If the bullet has a mass of 2.6 grams and the pendulum swings up to an angle 13.4 degrees, how fast was the bullet traveling when it struck the block?

Show all work and Thanks in advance!

Derive the energies for an infinite square well potential. Start from the Schrödinger Equation and show your work.

Please show all the work and steps and the math in details.
similar problem will be on my Exam, So I want to learn how to do this. Please write clear so I can read it.