1. What is reactance and why is different from resistance?

2. What is a phasor diagram and how is it useful? (No Star Trek answers, please.)

please I don't really know how to start answering this question I really need to understand it

please show the work with a clear handwriting

A collision in one dimension

A mass m1 = 2 kg moving at v1i = 3 ms−1 collides with another mass m2 = 4 kg moving at

v2i = −2 ms−1. After the collision the mass m1 moves at v1f = −3.66 ms−1. (a) Calculate the final velocity of the mass m2.

(b) After the collision the mass m1 slides across a surface with coefficient of friction μ = 0.6. Calculate how far it travels before it comes to rest.

1- What is the conclusion of the first video activity (Electric Force vs. Charge)?

Explain your answer by referring to the graph “Force vs. Charge” that you created in Part H of the first video activity. Please insert the data table and the graph side by side and then write your answer underneath.

Viedo Link: https://mediaplayer.pearsoncmg.com/assets/_frames.true/secs-coulomb-force-2-force-vs-charge

Part A

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Assume that the Styrofoam slab and the fur are both initially neutral, and that the slab charged negatively after it is rubbed with the fur. Describe what happens.

Mark all the correct statements among those provided below.

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Since the electrons are the mobile charge carriers, they are transferred in this case from the fur to the slab. As a result, the fur will have fewer electrons than it began with, thus leaving it positively charged.

Part B

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After the slab is charged, and the electrophorus is placed on the slab, the student briefly touches the electrophorus, effectively grounding it. After that, the electrophorus appears to be charged. By what method is it charged?

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Charging by induction means that a charged object (the slab) causes the other one (the electrophorus) to become charged by influencing (inducing) the process of charge transfer; however, little or almost no charge transfer occurs directly between the charging object and the object being charged.

What, exactly, is happening in this particular case?

Part C

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As the hand touches the electrophorus, in which direction do the electrons move?

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The negatively charged slab is pushing the “free” electrons in the conducting electrophorus away. Before the electrophorus is grounded, there is no escape path for those electrons. Therefore, the electrophorus is polarized; that is, its top surface is negative, and the bottom one, the one nearest the slab, is positive. However, the electrophorus remains neutral until the hand provides a conducting path that allows some electrons escape from the electrophorus, rendering it positive.

Part D

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Observe the process by which the grey and the red spheres are charged using the electrophorus. After each sphere is first charged, what are their charges?

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The electrophorus becomes less positive once it pulls some electrons away from the red sphere. However, the electrophorus is replaced on the slab and recharged by grounding it before it proceeds to charge the grey sphere. This ensures that both spheres initially have about the same amount of charge.

Since the red sphere is suspended on an insulating handle, and no other objects toch it, we cna assume that its charge remains constant throughout the experiment. However, this is not the case for the gray sphere.

Part E

Part complete

Before we proceed with the quantitative part of this set, let us make sure that you can see the reading of the electronic balance clearly on your screen. What is the reading of the scale right after the red sphere is first charged, and the electrophorus has been replaced on the slab? Use the “pause” and the “frame-by-frame-advance” buttons to navigate to the appropriate part in the video.

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Note that the scale has been adjusted so that it reads approximately zero when the only force acting on it is gravity. A small difference from zero is frequently observed with sensitive scales.

Part F

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What is the reading of the scale after both spheres have been charged, and the student is getting ready to bring the hand-held sphere close to the bottom sphere? Consider the moment when the hand-held sphere is about half-way between the handle of the electrophorus and the bottom sphere. Use the “pause” and the “frame-by-frame-advance” buttons to navigate to the appropriate part in the video.

Express your answer in Newtons. Use three significant figures in your answer.

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Now let us see what happens when the charge of the bottom sphere begins to change.

Part G

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The bottom sphere is briefly touched by another conducting sphere of the same size, mounted on an insulating handle. Assuming that the charge of the bottom sphere is +q+q before it is touched by the other sphere, what is its charge after it is touched?

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Note that, after each touch of the spheres, the handheld one is briefly touched by hand—that is, neutralized—through grounding. That means that each subsequent touch would remove half of the charge from the bottom sphere.

Part H

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We will now try to determine how the magnitude of the Coulomb force between the spheres depends on the charge of the bottom sphere. Now that we understand that the charge of the bottom sphere is halved after each touch, create a graph “force vs. charge of the bottom sphere” using +q+q, +q/2+q/2, +q/4+q/4, etc. as the charge values. What is the most reasonable conclusion that can be made from the graph about the magnitude of the Coulomb force?

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It seems reasonable to assume that the magnitude of the force would be also directly proportional to the charge of the top sphere—in other words, directly proportional to the product of the charges of the spheres! (Recall that the magnitude of the force of gravity between two spherical masses is directly proportional to the product of the masses of the spheres.)

Now, let's do one last exercise to make sure you are comfortable with this idea.

Part I

Part complete

Let us suppose the magnitude of the original Coulomb force between the two charged spheres is FF. In this scenario, a third sphere touches the grey sphere and the red sphere multiple times, being grounded each touch. If the grey sphere is touched twice, and the red sphere is touched three times, what is the magnitude of the Coulomb force between the spheres now?

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In another DMV-based activity, you will explore (if you haven’t already done that) the dependence of the Coulomb force on the distance between the spheres.

The words "entropy" and "the second law of thermodynamics" are often used interchangeably, but there is a difference. Describe the difference between “entropy” and “the second law of thermodynamics”.

3. a) Draw a schematic diagram of an X-ray diffractometer. [4 marks]

b) The results of an X-ray diffraction experiment that used X-rays of wavelength 0.154 nm show the first 6 peaks at angles of 40.6°, 58.8°, 73.8°, 87.8°, 101.8°, and 116.4°.

i) Use this information to determine the possible crystal structures of the sample. [10 marks]

ii) An additional scan was performed on the sample and an additional peak was observed at an angle of 133.2°. Determine the crystal structure of the sample. [3 marks]

iii) Calculate the Miller indices for each of the measured peaks. [7 marks]

iv) Draw the orientation of the crystal plane within the unit cell corresponding to the peak at 101.8°. [3 marks]

v) Calculate the lattice constant and identify the sample. [3 marks]

In 1963, Maarten Schmidt of the California Institute of Technology found the most distant object that had ever been seen in the universe so far. Called 3C273, it emitted electromagnetic radiation with a power of 2×1013 Suns, or 100 times that of the entire Milky Way galaxy! Schmidt called 3C273 a "Quasi-Stellar Radio Source," a name that was soon shortened to "quasar." Since then, astronomers have found many quasars, some substantially more powerful and distant than 3C273. Quasar 3C273 is moving away from Earth at about speed 0.16c. The Sun is 1.5×1011mfrom Earth and emits energy at a rate of 3.8×1026J/s caused by the conversion of 4.3×109kg/s of mass into light and other forms of electromagnetic energy. The Hubble constant is
H=70.8km/sMpc=70.8103m/s3.09×1022m==22.9×10−19s−1

Estimate the mass of 3C273 that is converted to light and other forms of radiation each minute. By comparison, the mass of Earth is 6×1024kg.

express your answer in Kg

A long pair of isolated wires provides a device with 12.5A direct current as input / output. If the diameters of the wires are negligible, but if there is a 2.8mm gap with each other, calculate the magnitude of the magnetic field at a distance of 10cm from the middle point of this gap and compare it with the magnetic field of the world and discuss your result.

Writing Task

1. in what ways are three temperature scales the same ?

2. In what ways are the three temperature scales different ?

3. At approximately what temperature would Celsius and Fahrenheit thermometer register the same reading ?

4. what is absolute zero temperature ? explain

2. The Cahora Bassa dam, located in Mozambique, is the highest dam in Africa. The hydroelectric facility within the dam generates an average 1,925 MWe. Nearly all of this electricity is exported to South Africa. The power station is linked to Pretoria, 1,420 km away, by a 533.0 kV high-voltage DC (HVDC) transmission line. a. The transmission line consists of eight cables made of aluminum with a steel core for strength and structural support. The total cross-sectional diameter of each cable is 28 mm, while the cross-sectional diameter of the steel core is 14 mm (consider the cross-sectional area as a steel circle in the middle of an an aluminum circle). Treat each cable as if it consisted of one steel and one aluminum resistor arranged in parallel, while the cables themselves are arranged in parallel with each other. What is the total resistance of the transmission line? Material resistivities:

ρ_steel=7.2〖*10〗^(-7) Ω•m

ρ_alum=2.7*10^(-8) Ω•m.

(15 points)

b. On average, how much current flows through the transmission lines? What is the power loss in the line? What is the percentage of power loss relative to the average power generated? (10 points)

c. If the power were transmitted at 333.0 kV over the same cables, what would the power loss percentage be? (10 points)

d. If the dam’s power is sold wholesale to South Africa for US$90.00/MWh, how much revenue would be lost per year, transmitting at 333.0 kV instead of 533.0 kV? (note: the 1,920 MW average production already accounts for the dam’s capacity factor) (5 points)

e. Say you are interested in doing a life cycle assessment to estimate the amount of energy used to build the Cahora Bassa power system, from dam to end user (not the amount energy produced by the system itself). Consider the major parts of the Cahora Bassa power system, from the dam, to the power lines, to the electrical equipment, and everything that was required to manufacture and build them. List ten energy-consuming materials or processes that would be used as inputs in a life-cycle assessment of the construction of this system. (10 points)

a) Describe in less than 300 words ONE type of apparatus (using a diagram if it helps) that is used to collect diffraction information using X-rays. Include in your answer why this set up is used to successfully get diffraction from crystals?

b) Describe in less than 300 words how the equilibrium one-dimensional band diagram of a pn junction (under zero bias) evolves based on diffusion and drift currents that occur due to the differing impurities in the p and n sides.

Write it clear please.

1. Why is the safety feature of a garage door opener mounted about 10 inches off the floor rather than higher?

2.Why do photons have to be massless?

Calculate the angle of incidence for the PV panel installed in

Brampton, at 3:00 p.m. July 10, facing due south with a tilt angle

same as the latitude. If the solar insolation at this point is 1000

W/m² ,calculate the insolation collected by the panel.

Faraday's Law: What would you observe about the amplitude of an induced signal as the frequency varied? Describe whether the behavior is consistenent with Eq. 3 (Vo= w(Nd)A(Bo)cos(theta)). In particular what should your graph of amplitudes against frequencies look like according to Eq 3? In comparisons with the predictions of Eq 3, why would it be important to adjust the function generator to keep the amplitude of the B field the same at each frequency?

We usually assume that your weight as measured by a scale is equal to the magnitude of the gravitational force that the earth exerts on you. Because of the rotation of the earth, however, the scale reading can actually be slightly different from your true weight. Which of the following accurately describes this effect?