# Katie

Popular questions and responses by Katie-
## Physics

The motion of a piston in an automobile engine is nearly simple harmonic. If the 1-kg piston travels back and forth over a total distance of 10.0 cm, what is its maximum speed when the engine is running at 3 000 rpm? The answer is 15.7 m/s but I don't

*asked on July 9, 2010* -
## Statistics

A local eat-in pizza restaurant wants to investigate the possibility of starting to deliver pizzas. The owner of the store has determined that home delivery will be successful if the average time spent on the deliveries does not exceed 30 minutes. The

*asked on November 8, 2013* -
## chemistry

Write the balanced chemical equation for each of these reactions. Include phases. When aqueous sodium hydroxide is added to a solution containing lead(II) nitrate, a solid precipitate forms. However, when additional aqueous hydroxide is added the

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

The rate constant for this first-order reaction is 0.320 s–1 at 400 °C. A--> Products How long (in seconds) would it take for the concentration of A to decrease from 0.830 M to 0.220 M?

*asked on March 23, 2012* -
## chemistry

At 25 °C only 0.0580 mol of the generic salt AB3 is soluble in 1.00 L of water. What is the Ksp of the salt at 25 °C?

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

How long will it take a charged 80-ìF capacitor to lose 20 percent of its initial energy when it is allowed to discharge through a 45 ohm resistor?

*asked on May 22, 2011* -
## Chemistry

Which of the following set of quantum numbers (ordered n, ℓ, mℓ, ms) are possible for an electron in an atom? Check all that apply. -4, 3, 1, 1/2 2, 1, -2, 1/2 4, 2, 1, -1/2 4, 2, -1, -1/2 2, 4, 1, -1/2 5, 3, -3, 1/2 5, 3, 4, 1/2 3, 2, 0, -2

*asked on October 11, 2018* -
## Chemistry

What is the maximum concentration of Ca2+ ions in a solution containing 0.010 M of F- ions?

*asked on May 10, 2012* -
## mathematics

An irrigation drip arm is 28 feet long and pivots about a center one revolution each hour. A “drip hole” H is located 28 feet from the pivot point. (a) What is the linear speed of H in units of feet/hour ,feet/minute ,feet/second , and inches/second .

*asked on July 20, 2020* -
## math

What is the period, in seconds, of a simple pendulum of length 3 meters? Use the gravitational constant g = 9.8 m/s2 and round your answer to two decimal places Please help! A step by step would with the answer would be helpful!

*asked on June 9, 2014* -
## chemistry

Calculate the standard free-energy change for the following reaction at 25 °C. 2Au^3+(aq) + 3Ni(s) -->2Au(s) + 3Ni^2+(aq)

*asked on February 29, 2012* -
## chemistry

What is the pH of a 2.8 M solution of HClO4?

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

gabriella volunteers 15 hours in a week. How many weeks in a year would that total in? - 10 hrs? - 4 hrs? - 3 hrs? - 2 hrs?

*asked on July 29, 2020* -
## Math

What are the odds of drawing a 5 from these cards? 1,2,3,4,5 I do not understand how to solve this. Thanks

*asked on September 18, 2016* -
## college physics

tennis ball rolls off the edge of a tabletop 0.900m above the floor and strikes the floor at a point 1.60m horizontally from the edge of the table. A: Find the time of flight of the ball B: Find the magnitude of the initial velocity of the ball. C: Find

*asked on September 22, 2014* -
## Chemistry

A solution contains 0.133 g of dissolved Lead. How many moles of soduim chloride must be added to the solution to completly precipitate all of the disolved lead? What mass of sodium chloride must be added?

*asked on May 14, 2011* -
## Trigonometry

If sin(x) = 4cos(x), then what is (sin(x))*(cos (x))?

*asked on April 4, 2016* -
## Statistics

The monthly incomes from a random sample of workers in a factory are shown below. Monthly Income (In $1,000) 4.0 5.0 7.0 4.0 6.0 6.0 7.0 9.0 a. Compute the standard error of the mean (in dollars). b. Compute the margin of error (in dollars) at 95%

*asked on November 12, 2013* -
## Trig

If you are dealt 3 cards from a shuffled deck of 52 cards, find the probability that all 3 cards are picture cards.

*asked on May 7, 2012* -
## chemistry

Give the chemical formula for trans-dichlorobis(ethylenediamine)platinum(IV). Use (en) as the symbol for ethylenediamine.

*asked on March 30, 2012* -
## Chemistry

The FDA recommends that women who are pregnant avoid eating more than three 6.00-oz servings of bluefish per month because of the relatively high mercury levels in that type of fish. If bluefish contains 0.341 ppm of mercury (that is, 0.341 oz of mercury

*asked on February 1, 2014* -
## Math

The bases on a baseball diamond are 27.4m apart. The pitcher pitches,and the batter hits a fly ball straight up 15m. What is the maximum angle of elevation of the ball to the nearest degree, as seen by the pitcher if he is standing at the center of the

*asked on November 28, 2016* -
## Math

Suppose p and q are points on the unit circle such that the line through p and q intersects the real axis. Show if z is the point where this line intersects the real axis, then z=(p+q)/(pq+1) So far I've figured out that the equation for the line is

*asked on May 31, 2016* -
## Math 141

Two cards are drawn from a well-shuffled deck of 52 playing cards. Let X denote the number of aces drawn. Find P(X = 0). (Round your answer to three decimal places.)

*asked on November 13, 2015* -
## Math

Gerald can complete a math assignment in 2 hours and a physics assignment in 1 hour. If he has 8 hours to complete a set of assignments, how many math assignments can he complete if he decides to leave the science assignments for the next day? This

*asked on May 27, 2013* -
## chemistry

What is the molecular geometry for SH2? 1. Bent 2. Trigonal planar 3. Tetrahedral 4. Liner

*asked on November 29, 2011* -
## literature

In the merchant of venice act 2 scene 2, Portia gives Bassanio the ring with a warning, and Bassanio accepts the ring with his own pledge. How is this contract or bond similar to and different from the one made in Venice? What significance did rings have

*asked on October 2, 2016* -
## Chemistry...

The oxygen gas emitted from an aquatic plant during photosynthesis is collected over water at a temperature of 25 degrees celsius and a total pressure of 762 torr. What is the partial pressure of the oxygen gas? What formula do I need to use?

*asked on February 20, 2013* -
## physics

A rock is dropped from a sea cliff, and the sound of it striking the ocean is heard 3.3 later. If the speed of sound is 340 , how high is the cliff?

*asked on September 17, 2010* -
## Precalculus

Let C be a circle that passes through the origin. Show that we can find real numbers s and t such that C is the graph of r = 2s*cos(theta + t) I think that I could start by writing it like R^2=(x-h)^2+(y-k)^2 where R is the radius of the circle, but I

*asked on April 18, 2016* -
## Physics

A small wooden block with mass 0.800kg is suspended from the lower end of a light cord that is 1.52m long. The block is initially at rest. A bullet with mass 0.0126kg is fired at the block with a horizontal velocity v0. The bullet strikes the block and

*asked on March 12, 2015* -
## MATH

a pile of bricks has 85 bricks in the bottom row, 79 bricks in the second row, 73 in the third row, and so on until there is only 1 brick in the top row. how many bricks are in the 12th row? how many rows are there in all?

*asked on October 31, 2011* -
## chemistry

Aerosol cans have a label that warns the user not to use them above a certain temperature and not to dispose of them by incineration. Even an empty can contains residual gaseous propellant. For example, the residual pressure in a can is 1.36 atm when it is

*asked on December 6, 2009* -
## physics

a ball is dropped from the top on an 80-m high building. what speed does the ball have in falling 3.5 s?

*asked on March 30, 2014* -
## chemistry

The reaction described by this equation O3(g) + NO(g) -- O2(g) + NO2(g) has the following rate law at 310 K. rate of reaction = 3.0x10^6 M^-1 s^-1)[O3][NO] Given that [O3]=2.0× 10–4 M and [NO]=2.0× 10–5 M at t=0, calculate the rate of the reaction at

*asked on March 23, 2012* -
## Math

Which of the following options results in a graph that shows exponential growth A.f(x)= 0.4(3)^x B.f(x)= 3(0.5)^x C.f(x)= 0.8(0.9)^x D.f(x)= 0.9(5)^-x

*asked on November 4, 2015* -
## Math

A spinner has 4 equal sections: red, white, blue, and green. john spins the spinner and tosses a coin. which shows the sample space for spinning the spinner and tossing the coin? I have a chart but I cant figure out how to get into this question.

*asked on March 12, 2019* -
## Math: Trigonometry

For how many values of n with 0

*asked on April 8, 2016* -
## Algebra

A rectangular playground is to be fenced off and divided in two by another fence parallel to one side of the playground. 440 feet of fencing is used. Find the dimensions of the playground that maximize the total enclosed area. Remember to reduce any

*asked on February 28, 2016* -
## General Chemistry

A certain protein was found to have 0.855% zinc by mass. Determine the minimum molecular mass of the protein. How do I go about solving this?

*asked on September 19, 2010* -
## Math

- If I spent 15 hours per week volunteering, how many hours in total weeks per year? - 4 hours? - 3 hours? - 2 hours?

*asked on July 25, 2020* -
## Chemistry

a) How many moles of atoms are in 7.00 g of 13C? Answer "0.538" mol 13C b) Based on your answer in Part A, calculate the number of atoms in this amount of 13C? Answer "3.24×10^23" 13C atom c) Based on your answer in Part B, how many electrons are in this

*asked on August 25, 2018* -
## physics

A block with mass m = 17 kg rests on a frictionless table and is accelerated by a spring with spring constant k = 4201 N/m after being compressed a distance x1 = 0.556 m from the spring’s unstretched length. The floor is frictionless except for a rough

*asked on March 20, 2018* -
## Math

An open gift box is to be made from a square piece of material by cutting four-centimeter squares from each corner and turning up the sides (see figure). The volume of the finished gift box is to be 324 cubic centimeters. Find the size of the original

*asked on February 11, 2016* -
## Chemistry

The Kc for the following reaction at 940oC is 1.38. Given the concentrations [CO2] = 0.500 M, [H2] = 0.425 M, [CO] = 0.610 M and [H2O] = 0.695 M, one can conclude that: H2(g) + CO2(g) ↔ CO(g) + H2O(g) Question 8 options: A) the system is not at

*asked on May 10, 2012* -
## Chemistry

A mixture of lead, magnesium, nitrate and chromate ions are present in a solution. What will the precipitate be? Question 2 options: A) MgPb B) Pb(NO3)2 C) PbCrO4 D) MgCO3

*asked on May 10, 2012* -
## chemistry

Construct the octahedral crystal-field splitting diagram for the metal in each species. Cr4+ Mn(H2O)6^2+

*asked on March 30, 2012* -
## anatomy

In the body, lever systems involve the interaction of __1__, which provide the force, and __2__, which provide the lever arms. The force is exerted where __3__. The site at which movement occurs in each case is the intervening __4__, which acts as a

*asked on November 22, 2011* -
## Chemistry

A solution contains an unknown amount of dissolved calcium . Addition of 0.112 mole of K3PO4 causes complete precipitation of all the calcium. How many moles of calcium were dissolved in the solution?

*asked on May 14, 2011* -
## Trig

How do I solve the following? sec 3 theta/2 = 2 on the interval 0

*asked on March 14, 2010* -
## Stats Class HELP!

Twenty-five blood samples were selected by taking every seventh blood sample from racks holding 187 blood samples from the morning draw at a medical center. The white blood count (WBC) was measured using a Coulter Counter Model S. The mean WBC was 8.636

*asked on April 18, 2014* -
## precalc

Points A, B, and C are on the circumference of a circle with radius 2 such that angle BAC = 45 degrees and angle ACB = 60 degrees. Find the area of triangle ABC.

*asked on July 15, 2016* -
## vectors

The minute hand of a wall clock measures 11 cm from its tip to the axis about which it rotates. The magnitude and angle of the displacement vector of the tip are to be determined for three time intervals. What are the (a) magnitude and (b) angle from a

*asked on February 2, 2015* -
## chemistry

Which of these ions have five d electrons in the outermost d subshell? Mn2+ Fe2+ Re2+ Y2+ Tc2+ Zn2+ Ru2+

*asked on March 30, 2012* -
## physics

Two identical steel balls, each of mass 5.0 kg, are suspended from strings of length 29 cm so that they touch when in their equilibrium position. We pull one of the balls back until its string makes an angle θ = 25° with the vertical and let it go. It

*asked on March 2, 2012* -
## physics

A satellite moves on a circular earth orbit that has a radius of 6.68E+6 m. A model airplane is flying on a 16.3 m guideline in a horizontal circle. The guideline is nearly parallel to the ground. Find the speed of the plane such that the plane and the

*asked on February 18, 2012* -
## Physics

A 3.0-m rod is pivoted about its left end. A force of 6.0 N is applied perpendicular to the rod at a distance of 1.2m from the pivot causing a CCW torque, and a force of 5.2N is applied at the end of the rod 3.0m from the pivot. the 5.2N is at an angle of

*asked on June 8, 2010* -
## Physics Number 3 (Online w/ no teacher)

Many people mistakenly believe that the astronauts that orbit the Earth are “above gravity.” Calculate g for space-shuttle territory, 200 kilometers above the Earth’s surface. Earths’ mass is 6 X 10 to the 24th and its radius is 6.38 X 10 to the

*asked on October 27, 2008* -
## Chemistry

A particular MP3 encoder can convert 79.0 kilobytes (kb) of music per second from a typical music CD. How many minutes will it take to convert 13.3 megabytes (Mb) of music from a CD?

*asked on January 29, 2014* -
## Science

What is the radius in nm of the electron orbit of a hydrogen atom for n=3? What is the radius in nm of the electron orbit of a hydrogen atom for n=4?

*asked on January 14, 2014* -
## College Chemistry

Calculate the ratio of NaF to HF required to create a buffer with pH=3.95. Also, can you please explain in a nutshell the whole concept of buffers? Thanks!

*asked on March 23, 2010* -
## English

What figurative language is "August is a day in the sun

*asked on October 8, 2019* -
## Algebra

The yearly per capita consumption of whole milk in the United States reached a peak of 40 gallons in 1945, at the end of World War II. By 1970 consumption was only 27.4 gallons per person. It has been steadily decreasing since 1970 at a rate of about 3.9%

*asked on April 9, 2017* -
## Math

If the probability that an identified hurricane will make a direct hit on a certain stretch of beach is 0.04, what is the probability against a direct hit? So if it is against, would I take 1-.04 and that would be the answer? Thanks!

*asked on February 17, 2017* -
## Physics

An electrostatic paint sprayer has a 0.200-m-diameter metal sphere at a potential of 25.0 kV that repels paint droplets onto a grounded object. What charge must a 0.100-mg drop of paint have to arrive at the object with a speed of 10.0 m/s?

*asked on July 14, 2013* -
## calculus

Using 4x^2 - 9y^2 = 36 Find y by implicit differentiation and then solve the equation explicitly for y and differentiate to get y' in terms of x.

*asked on April 29, 2013* -
## Math

Let a, b, and c be unit vectors, such that a+b+c=0. Show that the angle between any two of these vectors is 120 degrees. I proved this geometrically, but now my teacher wants a proof using vectors, and I don't know what to do.

*asked on June 7, 2016* -
## chemistry

If 25.0mL of 0.56 M H2SO4 is diluted to a volume of 125 mL, what is the molarity of the resulting solution?

*asked on October 28, 2012* -
## chemistry

A 20.0 mL sample of 0.687 M HBr is titrated with a 0.216 M NaOH solution. The pH after the addition of 10.0 mL of NaOH is __________.

*asked on July 24, 2012* -
## chemistry

what are the chemical formula for sodium tetrachloroplatinate(II) and tris(ethylenediamine)cobalt(III) bromide

*asked on March 30, 2012* -
## physics

Two children, each with mass m = 11.0 kg, sit on opposite ends of a narrow board with length L = 4.5 m, width W = 0.30 m, and mass M = 9.4 kg. The board is pivoted at its center and is free to rotate in a horizontal circle without friction. What is the

*asked on March 16, 2012* -
## chemistry

A solution of NaOH(aq) contains 6.2 g of NaOH(s) per 100.0 mL of solution. Calculate the pH and the pOH of the solution at 25 °C.

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

A 100 inch piece of wire is divided into 2 pieces and each piece is bent into a square. How should this be done in order of minimize the sum of the areas of the 2 squares? a) express the sum of the areas of the squares in terms of the lengths of x and y of

*asked on November 16, 2010* -
## Calculus

If the integral from a to b of f(x)dx=a+2b then integral from a to b of (f(x)+3)dx= ? The answer: 5b-2a How do I get to that answer??

*asked on January 11, 2010* -
## Math

A green paint is created by mixing 3 parts of yellow with every 5 parts of blue. How many gallons of yellow paint are needed to make 44 gal of this green paint?

*asked on November 2, 2017* -
## Math 141

Three machines turn out all the products in a factory, with the first machine producing 20% of the products, the second machine 15%, and the third machine 65%. The first machine produces defective products 17% of the time, the second machine 8% of the time

*asked on November 11, 2015* -
## Chemistry

An office heater puts out 2070 Btus (British thermal units) of energy in the form of heat per hour. Given that 1 Btu = 1.055 kJ, how many megajoules of energy in the form of heat can be produced per year (365 days) by the heater (assume continuous

*asked on February 1, 2014* -
## Math

190 students like the program 135 students think the program is unnecessary 220 students plan on running for student government next year. If a circle graph were made from this data, what would the measure of the central angle be for the group that likes

*asked on April 1, 2013* -
## statistics

In a certain region, the mean annual salary for plumbers is $51,000. Let x be a random variable that represents a plumber's salary. Assume the standard deviation is $1300. If a random sample of 100 plumbers is selected, what is the probability that the

*asked on February 25, 2013* -
## Physics

While stationary on a boat you are measuring the time it takes for the coin to leave your hand and hit the water.In order to measure that time you are tuned to the sound of the coin hitting the water. You know that it takes 5.5 seconds for the coin to

*asked on December 8, 2012* -
## Chemistry

Which of the following pairs of compounds will give a precipitate in a diluted solution? Question 4 options: A) Cu(NO3)2 and Na2CO3 B) KNO3 and NaCl C) MgCl2 and Ba(NO3)2 D) NH4Cl and Al2(SO4)3

*asked on May 10, 2012* -
## Probability

If you are dealt 3 cards from a shuffled deck of 52 cards, find the probability that all 3 cards are picture cards.

*asked on May 7, 2012* -
## geometry

in an equilateral triangle RST, R has coordinates (0.0)and T has coordinate of (2a,0).Find the coordinates of S in terms of a.

*asked on July 3, 2011* -
## Geometry

Glenda wants to glue glitter over a piece of felt shaped like a parallelogram with a height of 36 in. and a base of 46 in. If the glitter costs $1.20 per ft2 to cover the felt, how much will it cost to cover the felt? A) $55.20 B) $1987.2 C) $165.60 D)

*asked on September 15, 2010* -
## Physics

What angular speed (in revolutions/second) is needed for a centrifuge to produce an acceleration of 1000g at a radius arm of 15.0cm?

*asked on June 8, 2010* -
## chem

classify each of the following as a lewis acid or base: Cl- BeCl2 B(CH3)3 P(Ch3)3 Cl- is an acid right? i'm not sure i understand this concept very well. :[ and i tried looking at my notes already.

*asked on March 28, 2010* -
## Accounting

The Account Cycle Bob night opened "The general's favorite Fishing Hole" The fishing camp is open from April through September and attracts many famous college basketball coaches during the off-season. Guests typically register for one week, arriving on

*asked on June 5, 2008* -
## Calc

Question: Using trigonometry, add these two vectors. 7m/s [N30E] and 2m/s [S17E]. THIS is my answer: 6m/s [N45E] is this the correct answer?

*asked on June 29, 2008* -
## literature

In the merchant of venice act 3 scene 5, Antonio quips that the devil can cite scripture for his own purpose (I, iii, l.95). How does the scriptural debate between Launcelot and Jessica serve each character’s purpose? This debate has the potential to

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

In the merchant of venice act 3 scene 4, 1. What does Portia tell Lorenzo that she and Nerissa will do? What is their actual plan? 2. 1. How is Portia equipped to portray a man?

*asked on October 4, 2016* -
## math

A prize of $100, $200, $500, or $1000 will be randomly awarded to a game show contestant, with the probabilities of winning each prize shown in the table below. What is the expected value of the prize that will be awarded?

*asked on October 21, 2015* -
## Math

you have four $1 bills, two $5 bills, five $10 bills, and five $ 20 bills in your wallet. You select a bill at random. Without replacing the bill, you choose a second bill. What is P($1, then$ 10)?

*asked on April 22, 2015* -
## Statistics

To plan the budget for next year a college needs to estimate what impact current economic downturn might have on student requests for financial aid. Historically, this college has provided aid to 35% of its students. Officials look at a random sample of

*asked on November 11, 2013* -
## Statistics

The relationship between the number of games won during one season by a minor league baseball team and the average attendance at their home games is analyzed. A regression analysis to predict the average attendance from the number of games won gives the

*asked on May 25, 2013* -
## Chemistry

Calculate the [H+] of a solution obtained by mixing 1 L of hydrochloric acid 1.0 M with 1 litre of sodium hydroxide 0.990 M.

*asked on May 11, 2012* -
## physics please help:)

A car misses a turn and sinks into a shallow lake to a depth of 8.9 m. If the area of the car door is 0.51 m2, what is the force exerted on the outside of the door by the water? Note: 1 atm = 101.325 kPa. What is the force exerted on the inside of the door

*asked on April 1, 2012* -
## chemistry

Rank these species by their ability to act as an oxidizing agent. Na^+ I2 Cr^3+ F2 Put best oxidizing agent first and continue to have best reducing agent last.

*asked on February 29, 2012* -
## statistics

One year, professional sports players salaries averaged 1.6 million with a standard deviation of .7 million. Suppose a sample of 100 major league players was taken. Find the approximate probability that the average salary of the 100 players exceeded 1.1

*asked on September 4, 2011* -
## Math

The nominal rate of interest is 8% and the rate of inflation is 5%. A single deposit is invested for 10 years. Let: A= value of the investment at the end of 10 years measured in "constant dollars," i.e. in dollars valued at time 0. B= value of the

*asked on May 11, 2011* -
## trig

Find the sign of the expression if the terminal point determined by t is in the given quadrant. cos t X sec t in any given quadrant

*asked on December 1, 2010*