Answer the following short questions.

a. A rectangular block has a resistivity of ? and resistance of ?. If we scale it up in size by a factor of 2 in every direction, what is the new resistivity and resistance as a function of ? and ??

b. Small aircraft often use 24-V electrical systems rather than the 12-V systems used in automobiles, even though the electrical power requirements are roughly the same. This is because a 24-V system uses thinner wires and therefore weighs less. Explain this reasoning.

c. Show why the internal resistance of a source can be determined by dividing the open-circuit voltage by the short-circuit current.

d. Assuming each source has a small internal resistance, which circuit(s) would light up the light bulb? Which circuit(s) do you think would be likely to cause damage to the ammeter or voltmeter?

2. You have a battery, a voltmeter, and an ammeter, and you are asked to find the resistance perunit-length ?′ of a long spool of wire. You connect the voltmeter to the battery and it reads 3.2 V. You connect the battery to 20 m of the wire with the ammeter in series and it reads 9.6 A. You then connect a 50 m length of wire and the ammeter now reads 4.1 A.

a. What is the resistance per-unit-length of the wire and internal resistance of the battery?

b. If the wire is made from copper, with a resistivity of ? = 1.7×10−8 Ω⋅m, what is its diameter? c. What is the percentage of power dissipated within the internal resistance of the battery relative to the total power dissipated? Is this percentage larger, smaller, or the same as for the 50 m wire? 3. Consider the following circuit containing two sources, each with an internal resistance of 5 , and two load resistors, being 40  and 100 . a. How much current flows through this circuit and in what direction does it flow? b. What is the potential at a relative to ground? What is the potential at b relative to ground?

c. Where in the circuit is the potential the highest? Where is it the lowest?

d. Calculate the total power dissipated in both load resistors. 2 e. If the 100 Ω resistor is replaced by a short circuit, is the total power absorbed by the 40 Ω resistor greater than, equal to, or less than the total power initially absorbed by both resistors? f. How much power is supplied by each source? (Include the effect of the internal resistances.)

4. The average bulk resistivity inside the human body is about 5 Ω.m. The surface resistance of the skin varies considerably, from around 100,000 Ω for dry skin to 1000 Ω for wet skin. If the skin is broken and soaked in salt water, the skin resistance will even approach zero. Furthermore, the skin resistance can break down when voltages are high (above 500 V) or when voltages are changing (like under alternating current conditions). You can model the conducting path between the hands as three resistors in series. The first and third resistors represent the skin resistance while the second resistor represents the internal resistance of the body and can be modeled as a cylinder of diameter 10 cm and length 1.6 m.

a. Calculate the resistance between the hands for dry skin, wet skin, and broken soaked skin.

b. What potential difference would be needed for a lethal shock current of 100 mA in each of the three cases in part a (ignoring breakdown)?

c. Considering the chart below (taken from C. F. Dalziel, “Deleterious effects of electric shock,” 1961), how bad would a worst-case shock be from a 12 V DC car battery, your 50 V DC home phone line, and a 120 V 60 Hz wall outlet (i.e. with broken soaked skin)? Warning, don’t test any of these situations out at home! Despite your findings, there have been cases where people have died of an electric shock from a car battery. DC 60 Hz AC 10 kHz AC Effect Men Women Men Women Men Women Slight sensation on hand 1 mA 0.6 mA 0.4 mA 0.3 mA 7 mA 5 mA Perception threshold, median 5.2 mA 3.5 mA 1.1 mA 0.7 mA 12 mA 8 mA Shock, not painful and muscular control not lost 9 mA 6 mA 1.8 mA 1.2 mA 17 mA 11 mA Painful shock, muscular control lost by 0.5% 62 mA 41 mA 9 mA 6 mA 55 mA 37 mA Painful shock, let-go threshold, median 76 mA 51 mA 16 mA 10.5 mA 75 mA 50 mA Painful and severe shock, breathing difficult, muscular control lost by 99.5% 90 mA 60 mA 23 mA 15 mA 94 mA 63 mA Possible ventricular fibrillation 500 mA 500 mA 100 mA 100 mA n/a n/a

Two particles approach each other with equal and opposite speed v. The mass of one particle is m, and the mass of the other particle is nm, where n is just a unitless number. Snapshots of the system before, during, and after the elastic collision are shown above. After the collision the first particle moves in the exact opposite direction with speed 2.40v, and the speed of the second particle is unknown. What is the value of n?

A 12.0 V dc battery having no appreciable internal resistance, a 150.5 ohm resistor, an 11.2 mH inductor, and an open switch are all connected in series.
A)After the switch is closed, what is the time constant for this circuit ? 74.4 micro seconds
B)After the switch is closed, what is the maximum current that flows through it ? in A
C) What is the current 73.4 micro seconds after the switch is closed ? in A
D)After the switch is closed, what is the maximum energy stored in the inductor? in micro J

If velocity ​(V) and aggregate output ​(Y) remain constant at

​$5

and

​$1,250

billion​,

​respectively, what happens to the price level ​(P) if the money supply​ (M) declines from

​$425

billion to

​$325

​billion?

​Originally, the price level is

nothing.

​(Round

your response to two decimal​ places.)

After the money supply​ decreases, the price level is

Castaneda v. Partida is an important court case in which statistical methods were used as part of a legal argument. When reviewing this case, the Supreme Court used the phrase "two or three standard deviations" as a criterion for statistical significance. This Supreme Court review has served as the basis for many subsequent applications of statistical methods in legal settings. (The two or three standard deviations referred to by the Court are values of the z statistic and correspond to P-values of approximately 0.05 and 0.0026.) In Castaneda the plaintiffs alleged that the method for selecting juries in a county in Texas was biased against Mexican Americans. For the period of time at issue, there were 180,950 persons eligible for jury duty, of whom 143,150 were Mexican Americans. Of the 881 people selected for jury duty, 346 were Mexican Americans.

(a) What proportion of eligible voters were Mexican Americans? Let this value be p_o. (Round your answer to four decimal places.)

(b) Let p be the probability that a randomly selected juror is a Mexican American. The null hypothesis to be tested is H_o: p = p_o. Find the value of p̂ for this problem, compute the z statistic, and find the P-value. What do you conclude? (A finding of statistical significance in this circumstance does not constitute a proof of discrimination. It can be used, however, to establish a prima facie case. The burden of proof then shifts to the defense.) (Use α = 0.01. Round your test statistic to two decimal places and your P-value to four decimal places.)

z=

P-value=

(c) We can reformulate this exercise as a two-sample problem. Here we wish to compare the proportion of Mexican Americans among those selected as jurors with the proportion of Mexican Americans among those not selected as jurors. Let p₁ be the probability that a randomly selected juror is a Mexican American, and let p₂ be the probability that a randomly selected nonjuror is a Mexican American. Find the z statistic and its P-value. (Use α = 0.01. Round your test statistic to two decimal places and your P-value to four decimal places.)

z=

P-value=

Before completing the assignment, please review the Summary Case, Niles v. City of San Rafael in your text (pgs. 198-199).

In this case, negligence was successfully established against both the pediatrician and the hospital. Please reason through the elements of negligence as presented in this case and establish a case against both the pediatrician and hospital individually, utilizing the elements of negligence and the facts presented to make your case.

A charged particle with negative charge Q=-5C is moving with the speed v=400 m/s and the direction of the velocity vector is at 60 degrees above horizontal as shown in the figure below. The particle moves in the presence of the magnetic field B produced by the long horizontal wire with current I=100 A flowing to the right.

A.)Find the magnitude of the magnetic field B at the location of the particle, 10 cm above the wire. Give your answer in mT (10^-3 T) units.

B.)Find the direction of the magnetic field at the location of the particle.

Pick the correct answer out of multiple options

Pick the correct answer out of multiple options

horizontally to the right

pointing up

pointing out of the page

horizontally to the right

pointing into the page

pointing down

C.)Find the magnitude of the magnetic force acting on the moving particle. (in newtons)

D.) Find the magnitude of the horizontal component of the magnetic force. (in newtons)

E.)We assume that the x axis is horizontal in the paper plane pointing to the right, y axis is in paper plane pointing up, and z axiis is horizontal pointing out of paper plane. Thus x-z is the horizontal plane.

In this coordinate system determine the direction of the horizontal component of the magnetic force (vettical component is either along y or opposite to the y axis)

Pick the proper orientatioin of the horizontal force component.

along positive z direction (out of pager)

inclined at 30 degrees from negative z axis

along negative x direciton (to the left)

along +x axis (to the right)

inclinded at 60 degrees form positive z axis

inclined at 60 degrees from negative x axis

along negative z direction (into the page)

inclined at 30 degrees from positive x axis