# Student

Popular questions and responses by Student-
## Statistics

A confidence interval was used to estimate the proportion of statistics students that are females. A random sample of 72 statistics students generated the following 90% confidence interval: (0.438, 0.642). Based on the interval above, is the population

*asked on August 11, 2008* -
## physics

soo for physics, we did a lab where we launched a cart on a track on the floor and recorded time, distance, etc. to figure out things. one of the questions on the lab is: can you think of a simple follow-up experiment that would allow you to determine how

*asked on October 6, 2009* -
## CIGS AND CDTE FABRICATION

During manufacturing of a CIGS device, the metal back contact is deposited first, while in case of the CdTe solar cells, the back contact is deposited in the last processing step. What are the configurations of both cells: a) Both the CI(G)S and CdTe solar

*asked on October 10, 2015* -
## calculus

The point P(4, −2)lies on the curve y = 2/(3 − x). (a) If Q is the point(x, 2/(3 − x)),use your calculator to find the slope mPQ of the secant line PQ (correct to six decimal places) for the following values of x. 1) 3.9 mPQ= 2) 3.99 mPQ= 3)3.999

*asked on August 28, 2012* -
## AQ4.1.1 MICROMORPH MODULE

Consider a small module based on interconnected tandem cells of hydrogenated amorphous and microcrystalline silicon as depicted in the figure below. The Voc of a single tandem cell is 1.35V and the short-circuit density Jsc is 12mA/cm2. b)

*asked on October 10, 2015* -
## physics

A rock is thrown vertically upward with a speed of 14.0 m/s from the roof of a building that is 50.0 m above the ground. Assume free fall. In how many seconds after being thrown does the rock strike the ground? in s What is the speed of the rock just

*asked on September 5, 2011* -
## Data Management (Math)

A Canadian postal code uses six characters. The first, third, and fifth are letters, while the second, fourth, and sixth are digits. A U.S.A zip code contains five characters, all digits. How many codes are possible for each country?

*asked on June 19, 2011* -
## Chemistry Equilibrium

Which of the following conditions is always true at equilibrium? deltaG=0, Q=1, K=1, deltaG=deltaG(standard), deltaG(standard)=0, Q=0, deltaG(standard)=1 I'm so confused, please help!

*asked on March 14, 2013* -
## Economics

A man wishes to bequeath to his daughter P20,000 ten years from now. What amount should he invest now if it will earn interest of 8% compounded annually during the first 5 years and 12% compounded quarterly during the next 5 years?

*asked on June 24, 2018* -
## Math

How long would it take Belinda's $800 investment to double in value if she has a bond with a 8.75% interest rate?

*asked on March 31, 2020* -
## English

In The Story of An African Farm, Bonaparte speaks with Otto about the missing sheep. How is this interaction important to the story? It lays the groundwork for Bonaparte and Otto to develop a strong friendship. It clears the way for Otto and Tant Sannie to

*asked on February 28, 2020* -
## math

okay so i really need help please help i dont understand how to do this ive asked my teacher and i still dont understand is there an easier way to do this to where i could understand? Brayden, Howard, and Vincent are on the football team. During a game,

*asked on April 16, 2018* -
## circuits 2

Which of the following is true about the cut-off frequency ωB of a first-order low-pass filter? Suppose that the DC gain is 1. a.When the input is a sinusoid operating at ωB, the output is phase shifted from the input phase by −45∘. b.The Bode

*asked on April 6, 2018* -
## Chemistry

If an electric discharge produces 300 liters of ozone (O3), how many liters of oxygen (O2) are required? 3O2->2O3

*asked on January 21, 2018* -
## chemistry

Find the formula for the compound that contains 72.4% iron and 27.6% oxygen.

*asked on January 22, 2012* -
## precal

A pile driver pounds a steel column into the ground. On the first drive, the column is pounded 1.65 metres into the ground, and on each successive drive it moves 80% as far as it did on the previous drive. The least number of drives required to drive the

*asked on October 14, 2012* -
## history

All of the following statements regarding the Monroe Doctrine are correct EXCEPT? A. Issued by Monroe in response to an onslaught by European monarchies against democracy in the Americas. B. Would have been ineffective without the backing of the British

*asked on February 14, 2012* -
## Chemistry

The pH of a 0.0050 M aqueous solution of calcium hydroxide is? Make sure to include all equations.

*asked on December 3, 2010* -
## Circuits2

An alternating current and a direct current flows simultaneously in the same conductor. if the effective value of the alternating current is 5A and the direct current is 10 A, what will an AC ammeter read when connected in the circuit?

*asked on March 26, 2018* -
## Chemistry

A reaction in which X and Y form products was found to be second order in X and first order in Y. By what factor will the rate of the reaction change if [X] is doubled and [Y] is tripled? a. 10 b. 12 c. 20 d. 2

*asked on February 19, 2015* -
## Circuits 2

a coil has resistance of 50 ohms and reactance of 70 ohm's. a capacitor is connected in parallel to produce resonance. the source is 120v. what is the power drawn by the circuit ?

*asked on March 25, 2018* -
## Chemistry

The reaction of CH4 in 2CH4(g) ---->/

*asked on February 28, 2016* -
## civics

Which of the following would be part of the Republican Party Platform? A. creating a new health care system B. banning hand gun use C. reducing the size of government D. raising taxes on the wealthy I think the answer is C.

*asked on May 30, 2015* -
## Poetry/British Literature/12th grade

Which of the following poems is a dramatic monologue? (A) "My Last Duchess" (B) "Love Among the Ruins" (C) Childe Roland to the Dark Tower Came (D) all of these

*asked on August 27, 2013* -
## CHEM HELP!

NH4HSNH3+H2S What is the minimum mass of NH4HS that must be added to the 5.00-L flask when charged with the 0.300g of pure H2S, at 25C to achieve equilibrium?? Kp=.120 at 25C initial pressure of H2S in flask = .0431atm partial pressures of H2S and NH3

*asked on March 12, 2012* -
## chemistry

You react chemical A with chemical B to make one product. It takes 100 grams of chemical A to react completely with 20 grams of chemical B. What is true about the chemical properties of the product? a. the properties are more like those of chemical A b.

*asked on February 13, 2012* -
## chemistry

Which of the following is considered a Lewis acid or a Lewis base. I- H2O BCl3 NH3 OH- H+ CO2 SO2

*asked on July 16, 2010* -
## statistics help

The branch manager of an outlet (Store 1) of a nationwide chain of pet supply stores wants to study characteristics of her customers. In particular, she decides to focus on two variables: the amount of money spent by customers and whether the customers own

*asked on July 28, 2008* -
## Circuits 2

a circuit with an ideal transformer with a source voltage, Vs=10cos(ωt)V, N1:N2=1:4, and RL=50Ω. What is the magnitude of the current on the primary side of the transformer?

*asked on April 10, 2018* -
## ~*Math Probability*~

Which expression would you use to figure out the number of ways you can arrange the letters in the word equation? (1 point) 8! 8P4 4P8 4! Five friends are having their picture taken. How many ways can the photographer arrange the friends in a row? (1

*asked on March 13, 2013* -
## Circuits 2

V1 has rms voltage of Vrms=10V. The turn ratio of the primary to secondary side of the transformer is 1:10. If R1 has a value of 20Ω, what is the value of the rms current on the secondary side? what is the value of the rms current on the primary side?

*asked on April 10, 2018* -
## Circuits 2

For the circuit below, V1 has rms voltage of Vrms=10V. The turn ratio of the primary to secondary side of the transformer is 1:10. If R1 has a value of 20Ω, what is the value of the rms current on the secondary side? Enter your answer in units of Amps.

*asked on April 9, 2018* -
## Circuits2

Three impedances zL=3+j4 ohms, zC=4-j4 ohms and zR=0+j3 ohms are connected in parallel. solve for the power factor of the combination.

*asked on March 5, 2018* -
## Math

A system of equations is shown below: x + y = 3 2x − y = 6 The x-coordinate of the solution to this system of equations is _____. I'm thinking it could be X=3

*asked on December 11, 2015* -
## 9th Grade Algebra

If a is not equal to 0, and a =2b=3c, what is the value of a+b in terms of c? Would I make up numbers for the variables?

*asked on February 7, 2015* -
## english

Both texts deal with racial discrimination. How does the structure of poem help convey this meaning in a way that the prose passage does not? A)The poem conveys meaning through imagery; the prose passage does not. B)The poem uses first person point of

*asked on November 6, 2014* -
## Chemistry

Given the following equations, calculate the ΔH of reaction of ethylene gas (C2H4) with fluorine gas to make carbon tetrafluoride (CF4) gas and hydrogen fluoride gas. Show your work. H2 (g) + F2 (g) → 2HF (g) ΔH = –537 kJ C (s) + 2F2 (g) → CF4 (g)

*asked on April 18, 2019* -
## Chemistry-Dr.Bob 222

1. The rate constant for a second order reaction has units of L mol^-1 s^-1. What are the units of the frequency factor, A, for a second order reaction?

*asked on February 19, 2016* -
## Chemistry

A solution containing equal masses of glycerol, C3H8O3, and water has a density of 1.10 g/mL. Calculate the molality of glycerol. I got 11.9 m.

*asked on February 14, 2016* -
## Chemistry

1. As the intermolecular forces between molecules increase in magnitude, do you expect each of the following to increase, decrease or remain the same? My answers: Viscosity: increase Boiling point: increase Vapor pressure: decrease Surface tension:

*asked on February 13, 2016* -
## U.S History

Which of these describes the location of the Gulf of Mexico? (5 points) South of West Florida East of East Florida*** West of New Orleans South of Great Britain 4. © 2012 The Exploration Company What can you infer about what Lewis and Clark saw as they

*asked on January 5, 2016* -
## Algebra

The perimeter of a square must be greater than 40 inches but less than 94 inches. Find the range of possible side lengths yay satisfy these conditions.

*asked on January 5, 2016* -
## civics

A political communication that uses a picture to represent something else is an example of ______. A. bias B. prejudice C. propaganda D. symbolism I think the answer is D.

*asked on May 30, 2015* -
## chemistry

what are the islamic values in the experiment composition of potassium chlorate?I have to do lab report about the topic and the due date is around the corner.please help me..

*asked on March 14, 2015* -
## Algebra

I have a word problem here. A batter hits a fly ball. A scout in the stands makes the following observations. Time (in secs) .75, 1.5, 2, 2.75, 3.25, and 4.75 Height (in feet) 77, 133, 160, 187, 194, and 169 1.What type of function best models this data?

*asked on February 28, 2014* -
## Math/Algebra

A bridge is built in the shape of a semi elliptical arch. It has a span of 96 feet. The height of the arch 29 feet from the center is to be 10 feet. Find the height of the arch at its center.

*asked on May 28, 2013* -
## chemistry

What mass of water must be added to 0.5 mol of glucose to make a solution of 25 percent by mass?The molar mass of glucose is 180 g/mol.

*asked on January 22, 2012* -
## physics help

a fireman D=50 m away from a burning building directs a stream of water from a ground-level fire hose at an angle of 30 degrees above the horizontal. If the speed of the stream as it leaves the hose is 40.0 m/s at what height will the stream of water

*asked on October 2, 2011* -
## Algebra 2

Find the sum of the first six terms of the geometric series 81 -27 +9 -... how do you work it??

*asked on December 12, 2010* -
## PHYSICS

A ball of mass m at rest at the coordinate origin exploded into three equal pieces. At a certain instant, one piece is on the x-axis at x=40cm, and another is at x=20cm, y= -60 cm. Where is the third piece at that instant.

*asked on April 8, 2010* -
## Statistics

A quality control engineer is interested in the mean length of sheet insulation being cut automatically by machine. The desired length of the insulation is 12 ft. It is known that the standard deviation in the cutting length is 0.15 ft. A sample of 70 ut

*asked on August 10, 2008* -
## Chemistry

Baking soda is sodium bicarbonate (NaHCO3). When you heat baking soda, it breaks down into sodium carbonate powder (Na2CO3), water vapor, and carbon dioxide. The enthalpy of this reaction is 129 kJ. Write a correct thermochemical equation for this

*asked on April 18, 2019* -
## Algebra

I need help with this portfolio and I was wondering if someone could help me understand it. Task 1 Volume and surface area are often compared by manufacturers in order to maximize how much of something can go inside of a package (volume) while keeping how

*asked on May 8, 2018* -
## circuits 2

a 25ohm resistor connected in series with a coil of 500ohm resistance and 150mH inductance. What is the power factor of the circuit? NOTE: since not given, assume a standard electrical frequency of 60Hz.

*asked on February 5, 2018* -
## I am in class7

Find the average of 89,90,95,72,83,100,94 with full formula

*asked on July 25, 2017* -
## Psychology

I wanted to know if someone could give me an example of hypotheses for a 2 x 2 factorial anova

*asked on May 31, 2014* -
## Statistics

You take a trip by air that involves three independent flights. If there is an 67% chance each specific leg of the trip is on time, what is the probability all three flights arrive on time? (Round your answer to 3 decimal places.) Probability =??

*asked on April 4, 2014* -
## HISTORY PLEASE HELP!

The earliest and most enthusiastic proponents of Manifest Destiny were: A. Investment Bankers B. Eastern Politicians C. Northeast Industrialists D. Southern Proslavery Advocates E. Protestant missionary groups

*asked on April 17, 2012* -
## chemistry help!!!!!

Consider the following reaction: Find the equilibrium partial pressures of A and B for each of the following different values of Kp. Assume that the initial partial pressure of B in each case is 1.0 atm, and that the initial partial pressure of A is 0.0

*asked on March 11, 2012* -
## chemistry, chemical kinetics

I keep getting these questions wrong, could someone please help. Thanks so much. Question 1 For the following overall reaction, the rate constant is 3.4x10^-2. A(g)+ 2B -> 2C + D What may be the rate reaction? Question 2 The rate law for this reaction is

*asked on July 2, 2010* -
## biology

The length of DNA HELIX occupied by one nucleotide pair is 3.4 angstroms. What is the length in angstroms of this unknown DNA fragment? How do you calculate Angstroms?

*asked on September 17, 2009* -
## Biology

What types of proteins are made by free proteins and bound ribosomes?

*asked on April 24, 2020* -
## Algebra

2. Use an augmented matrix to solve the system. x + y = 5 3x – y = –1 (1 point) (1, 4) (1, 5) (3, –1)*** (5, –1) 3. When converting a system of linear equations into an augmented matrix, what equation form is needed? (1 point) slope-intercept form

*asked on January 21, 2019* -
## Social Studies

1. Which concept did the Maya understand before Europeans did? Architecture Calendars Hieroglyphics The number zero** 2. Which of the following BEST explains how the Mayans adapted their environment? The Mayans developed a nomadic lifestyle to hunt for

*asked on December 6, 2018* -
## Algebra

Simplify 4*sqrt6/sqrt30 by rationalizing the denominator. 4√6/√30 4√(6/30) 4√(1/5) 4/√5 4√5/5 Am I right?

*asked on May 2, 2018* -
## Circuits 2

Consider the ideal transformer, where i1(t)=20cos(120πt) Amps and v1(t)=100cos(120πt−45∘) volts, and a = 1 and b = 10. What is the rms value of i2 in amps? what is the amplitude of i2 in amps?

*asked on April 10, 2018* -
## Circuits 2

let R=20kΩ, L=10mH, and C=40μF. Which angular frequency ω is attenuated most by this filter? (It would help you to first identify what type of filter this is.) Give your answer in terms of rad/sec, and omit units from your answer.

*asked on April 3, 2018* -
## Circuits2

A series circuit containing a 295 microfarad capacitor and a coil whose resistance and inductance are 3 ohms and 4.42 mH, respectively are supplied by the following series connected generators: 35 V at 60 Hz, 10 V at 180 Hz and 8 V at 240 Hz. Determine the

*asked on March 26, 2018* -
## CIRCUITS 2

Two relays each with 20 ohms resistance and 0.16 henry inductance are connected in series. What is the equivalent impedance?

*asked on February 12, 2018* -
## Chemistry

A pyrotechnician mixes 280 g of black powder for a firework. Find the amount of oxygen, carbon dioxide, and sulfur dioxide generated when this firework bursts, if the oxidizing agent in the powder is saltpeter. How do I find their amounts?

*asked on January 21, 2018* -
## Calculus

he table below shows the temperature (in °F) t hours after midnight in Phoenix on March 15. The table shows values of this function recorded every two hours. (10 points) a. Estimate the value of T'(8). Give units in your answer. b. What is the meaning of

*asked on December 8, 2017* -
## Social Studies

9. Which of the following statements comparing the Continental and British armies is most accurate? A. The British had more troops and were better disciplined than the Americans. B. The British had limited access to supplies while the American supplies

*asked on October 20, 2016* -
## Physics

An object is shot upwards, from the ground, with an initial velocity of 120 m/s. How high will it be after 4.0s?

*asked on October 5, 2016* -
## Physics

An object, initially at rest, is subject to an acceleration if 34 m/s^2. how long will it take for that object to travel 3400m

*asked on October 5, 2016* -
## Art Please Ms.Sue Help

1.How do landscape paintings convey the values and ideas of Chinese culture? A.Landscape paintings show chaotic, unhappy culture. B.Landscape paintings reveal the importance of natural history to the Chinese. C.Landscape paintings show that Chinese desire

*asked on March 11, 2016* -
## Economics

4. Deregulation and the Cost of Trucking. Suppose the government initially limits the number of trucking firms that can haul freight. The market for truck freight is served by a single firm that produces five million ton-miles of service per year, where

*asked on February 14, 2016* -
## Chemistry-Dr.Bob

The solubility of CO2 in water at 25 degrees Celsius and P CO2= 1 atm is 0.034 mol/L. What is its water solubility under normal atmospheric conditions (in air, carbon dioxide is about 380 ppmv assuming that CO2 obeys Henry's Law?

*asked on February 13, 2016* -
## Math, pre-algebra

The volume of a rectangular prism is 6x^3 -x^2 -2x. Which model could represent the rectangular prism? A. Height: 3x-2 Length: 2x+1 Width: x B. Height: 3x+2 Length: 2x-1 Width: x C. Height: 3x-2 Length: 2x-1 Width: x D. Height: 2x-2 Length: 3x+1 Width: x I

*asked on January 29, 2016* -
## Language Art

1.)In "The Drummer Boy Of Shiloh", what does the general call the drummer boy? A.)The BRAINS OF THE ARMY b.)The Heart Of The Army C.)The Backbone of the army D.)The PRIDE OF THE ARMY

*asked on September 30, 2015* -
## Math

your management company was hired to take over the maintenance of the room. last year the old floor tiles were replaced with spanish portico special ceramic tiles. the tiles cost $13.50 per square foot. the owner paid $6534 for the tiles. Determine the

*asked on September 20, 2015* -
## civics

Which of the following actions is most typical of foreign policy intervention? A. The president creates a new economic plan. B. A task force is asked to investigate a possible free trade violation. C. The Environmental Protection Agency regulates

*asked on May 29, 2015* -
## Science

Which of the following describes the use of a renewable energy source? A. using natural gas to heat a house B. using a windmill to grind grain C. using petroleum to run a car D. using coal to generate electricity I think the answer is B.

*asked on May 27, 2015* -
## Civics

Leaders from several states of a nation meet once a year to settle common issues. They govern their own states independently, but they work together on issues that affect them all like trade and defense. They do not have a central government that handles

*asked on April 28, 2015* -
## civics

Which of the following forces us to make choices? a) scarcity b) trade offs c) opportunity cost d) money

*asked on March 25, 2015* -
## Corporate Finance

Suppose you have been hired as a financial consultant to Defense Electronics, Inc. (DEI), a large, publicly traded firm that is the market share leader in radar detection systems (RDSs). The company is looking at setting up a manufacturing plant overseas

*asked on March 14, 2015* -
## Math

There were 25 turkey balloons, 12 pilgrim balloons, and 30 native american balloons. Seventeen of the turkey balloons popped. How many balloons were left?

*asked on March 2, 2015* -
## Math

Jay's favorite football game was over on Thanksgiving Day at 11:45 a.m. The Thanksgiving dinner was served at 2:15 p.m. How long after the game did Jay have to wait for dinner?

*asked on March 2, 2015* -
## Algebra

Complete the table for each function. 1. f(x) = √x The x values are 0, 1,4 and 9. The corresponding y values that I got are 0, 1, 2 and 3. 2. g(x) = -1/4√ x The x values are 0, 1, 4, and 9. The corresponding y values that I got are 0, -1/4, -1/2 and

*asked on March 11, 2014* -
## math/algebra

solve the equation log2(3x-2) - log2 (x-5)=4

*asked on June 23, 2013* -
## Math/Algebra

Sketch the graph of each piecwise-defined function. Determine the domain and range. Identify each point of discontinuity. f(x)= -x if x

*asked on May 28, 2013* -
## Math/Algebra

Find the vertex, Focus,and Directrix of the parabola. Graph the equation. y^2=12x

*asked on May 28, 2013* -
## chemistry

You wish to increase the carbon content of a slab of steel by exposing it to a carburizing atmosphere at elevated temperature. The carbon concentration in the steel before carburization is 165.0 ppm and is initially uniform through the thickness of the

*asked on December 14, 2012* -
## Chemistry

Complete combustion of 7.70 g of a hydrocarbon produced 23.7 g of CO2 and 10.9 of H2O. What is the empirical formula of the hydrocarbon? I first calculated the moles of both the carbon dioxide and the water, but I have no idea where to go from there. Any

*asked on January 27, 2011* -
## 11th grade CHEMISTRY TITRATION LAB!

i have a tritation lab due tomorrow and i am stumped on a couple things. its a titration lab using sodium hydroxide (NaOH)- 250 mL 0.300 M concentration, 10 mL of an unknown substance of vinegar, the avg. of titrated NaOH in the flask with vinegar is 27.7

*asked on December 14, 2008* -
## Stats

A bank with a branch located in a commercial district of a city has developed an improved process for serving customers during the noon-to-1 p.m. lunch period. The waiting time (operationally defined as the time elapsed from when the customer enters the

*asked on August 13, 2008* -
## chemistry

I have already posted this and never got a response, please help. here is my data from lab: Buffer1: HPO4- weight 3.412g; original pH Buffer 2: HEPES wt: 1.090g original pH 10.08 buffer1: pH of 0.1M: 7.5; pH of 0.01: 7.72; pH of 0.001M: 7.87 buffer2: PH of

*asked on February 3, 2008* -
## Physics

A uniform plank of length 5.1 m and weight 235 N rests horizontally on two supports, with 1.1 m of the plank hanging over the right support (see the drawing). To what distance x can a person who weighs 458 N walk on the overhanging part of the plank before

*asked on October 8, 2007* -
## math, help

I need help or hint on the setup: what is the probability that at least 2 students in a class of 36 have the same birthday? This is 1 minus the probability that all students have different birthdays. Suppose that the birthday of a student is completely

*asked on July 15, 2007* -
## math,help & correction

the question asks: How many 5-card poker hands consisting of 2aces and 3 kings are possible with an ordinary 52-card deck? this is what i did: "c"=stands for combination (4C2) * (4C3) = 6*4 = 24 (52C5) = 259860 so then i divided : (24)/(259860)=

*asked on July 15, 2007* -
## Algebra

The perimeter of a soccer field is 340m. The length exceeds width by 50m. Find the Length and Width.

*asked on February 15, 2020*