# Erica

Popular questions and responses by Erica-
## Pre-Calculus

The formula D= 5e ^-0.4h can be used to find the number of milligrams D of a certain drug that is in a patient's bloodstream h hours after the drug has been administered. When the number of milligrams reaches 2, the drug is to be administered again. WHat

*asked on October 10, 2006* -
## Calc

The number of bacteria in a culture is increasing according to the law of exponential growth. There are 125 bacteria in the culture after 2 hours and 350 bacteria after 4 hours. a) Find the initial population. b) Write an exponential growth model for the

*asked on January 6, 2011* -
## Physics

A 50.0 g silver spoon at 20.0 degrees Celsius is placed in a cup of coffee at 90.0 degrees C. How much heat does the spoon absorb from the coffee to reach a temp. of 89.0 degrees C? Rememeber this equation. It, or a slight modification of it, will work all

*asked on November 21, 2006* -
## History

Which identifies the covert Armenian mission to assassinate high-ranking Ottoman officials responsible for the Armenian Genocide? Operation Overlord Gallipoli Campaign Operation Nemesis Justice Mission

*asked on July 10, 2020* -
## physics

How much heat is necessary to change 500g of ice at-10 celsius to water at 20 celsius?

*asked on October 15, 2012* -
## Calc

Use differentials to approximate the change in the volume of a cube when the side is decreased from 8 to 7.99 cm. (in cm^3) Thank you so much!!

*asked on April 25, 2011* -
## Calc

A body of an unknown temperature was placed in a room that was held at 30°F. After 10 minutes, the body's temperature was 0°F, and 20 minutes after the body was placed in the room the body's temperature was 15°F. Estimate the body's initial temperature.

*asked on January 6, 2011* -
## Science-Physics

You push a 67 kg box across a floor where the coefficient of kinetic friction is uk = .55. The force you exert is horizontal. (a) How much power is needed to push the box at a speed of .50 m/s? (b) How much work do you do if you push the box for 35 s?

*asked on January 9, 2011* -
## Calc

Let f be the function given by f(x) = tan x and let g be the function given by g(x) = x^2. At what value of x in the interval 0≤x≤π do the graphs of f and g have parallel tangent lines?

*asked on January 2, 2011* -
## Psychology

Classical Conditioning. 1)Terell feels ill every time he sees a Wendy's restaurant sign. Two weeks ago while on his lunch break, he went to Wendy's and ate a chicken sandwich. He was not aware that the chicken was spoiled. a. Name the Unconditioned

*asked on July 12, 2015* -
## Statistics

A group of 56 randomly selected students have a mean score of 30.8 and a standard deviation of ó = 4.5 on a placement test. Find a 95% confidence interval for the mean score, ì, of all students taking the test.

*asked on November 1, 2010* -
## Differential Equations

Consider the differential equation: dy/dt=y/t^2 a) Show that the constant function y1(t)=0 is a solution. b)Show that there are infinitely many other functions that satisfy the differential equation, that agree with this solution when t0 [Hint: you need to

*asked on January 31, 2013* -
## Chemistry

I need help please I am so confused. How much dry solute would you take to prepare each of the following solutions from the dry solute and the solvent? I know the MM of KCl is 74.55 107g of 0.535m KCl

*asked on September 18, 2012* -
## Algebra 2

From 1990 to 1994, the mail order sales of health products in the United States can be modeled by S = 10t 3 + 115t 2 + 25t + 2505 where S is the sales (in millions of dollars) and t is the number of years since 1990. In what year were about $3885 million

*asked on December 30, 2011* -
## Calc

If f(x) = e^(sin x), how many zeros does f '(x) have on the closed interval [0, 2π]?

*asked on January 2, 2011* -
## History

What is Social Darwinism? A.)the theory that the principle of natural selection applies to humans as well as animals and plants B.)the idea that other societies have to accept European culture in order to be regarded as civilized C.)the application of

*asked on July 7, 2020* -
## Math 221

what is 13/15 divided by 7/10

*asked on July 13, 2014* -
## Finance

Determine the annual net cost of this checking account? Annual interest of 2.5% paid if balance exceeds $750, $8 monthly fee if account falls below minimum balance, average balance $815, account falls below $750 during 4 months. Is my answer correct? 815 *

*asked on August 8, 2013* -
## Pre Calculs

The pH of a chemical solution is given by the formula pH = -log10 [H+] where [H+] is the concentration of hydrogen ions in moles per liter. Values of pH range from 0 (acidic) to 14 (alkaline). (a) what is the pH of the solution for which [H+] is 0.1? (b)

*asked on October 10, 2006* -
## Chemistry

The density of aluminum is 2.70 g/ml. What is the mass of a cube of Al that measures 2.20 cm on each side?(remember significant figures and to include the units of g in your answer, remember that 1 ml=1 cm3)

*asked on September 14, 2015* -
## Managarial Finance

"Stephenson Real Estate Company was founded 25 years ago by the current CEO, Robert Stephenson. The company purchases real estate, including land and buildings, and rents the property to tenants. The company has shown a profit every year for the past 18

*asked on October 8, 2012* -
## Calc

Find the area of the largest rectangle that can be inscribed under the curve y = e^(-x^2) in the first and second quadrants.

*asked on December 7, 2010* -
## Physics

Which provides more cooling for a styrofoam cooler, one with 10 lbs of ice at 0 degrees C or one with 10 lbs of ice water at 0 degrees C. Explain. qice=mass*heat of fusion. qH2O=mass*specific heat x delta T However, you aren't given a two temperatures;

*asked on November 21, 2006* -
## Chemistry

Calculate the change in enthalpy produced by dissolving 14.3 g of NaOH in 65.0 g of water if the temperature increases 49.1°C and the specific heat of water is 4.18 J/g°C Do I have to use the 14.3g of NaOH?

*asked on February 7, 2018* -
## chemistry

Convert 1.01 x 10-8 seconds to nanoseconds

*asked on September 14, 2015* -
## Psychology

Classical Conditioning. 2. Pat feels fear whenever she sees snow. Not too long ago, she got into a car accident on a snowy road. a. Name the unconditioned stimulus(US): Car accident b. Name the conditioned stimulus(CS): Seeing snow c. Name the

*asked on July 12, 2015* -
## math

a small farm field is a square measuring 340 ft on a side. what is the perimeter of the field?

*asked on July 26, 2013* -
## weber state university

CH2=CH-CH2CH3+H2O What is the product of the reaction above

*asked on April 11, 2013* -
## stats

A company with a large fleet of cars found that the emissions systems of 18 out of the 65 randomly selected cars they tested failed to meet pollution control guidelines. Is this strong evidence that more than 20% of the fleet might be out of compliance?

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

A bag of sugar weighs 4.00 lb on Earth. What would it weigh in newtons on the Moon, where the free-fall acceleration is one-sixth that on Earth? 1 N Repeat for Jupiter, where g is 2.64 times that on Earth. 2 N Find the mass of the bag of sugar in kilograms

*asked on September 16, 2010* -
## History

What was the outcome of the 1914 Battle of Tannenberg on the eastern front? The battle resulted in a stalemate as both Russian and German armies suffered heavy losses. The battle caused Russia to seek a peace treaty to end its conflict with Germany. Russia

*asked on July 9, 2020* -
## Mathematics

The segment shown is half of AB, where B (-5,1) is one endpoint of the segment and M (-3,3) is the midpoint of the segment. What are the coordinates of point A

*asked on June 5, 2020* -
## math

A certain test is worth 145 points. How man points are needed to obtain a score of $65%?

*asked on July 27, 2014* -
## Physics 1

The drawing shows three particles far away from any other objects and located on a straight line. Particle B is located in the middle of particles A and C. The distance between particles A and B is 0.500 m. The distance between particles B and C is 0.250

*asked on February 19, 2014* -
## math

a popular tourist attraction in ottawa is the Peace tower, which rises from the Center Block of the Parliment buildings. Describe at least one method that you could use to estimate the height of the tower, including the measurments you would need to make.

*asked on August 13, 2012* -
## alg

An amplifier has an input power of 5 mW. The output power is 100 mW. What is the decibel gain to the nearest decibel?

*asked on June 28, 2012* -
## Algebra 2

Find the value of c that makes the expression a perfect square trinomial. Then write the expression as the square of a binomial. I didn't really understand what that meant. x^2-23x+c x^2-(2/7)x+c

*asked on December 5, 2011* -
## global history

the wealth that enabled the Italian city-states to lead in the development of Renaissance arts was derived mainly from? a)the quantities of gold and silver brought back to Italian explorers b)concentration of riches in the hands of the king and his court

*asked on May 31, 2011* -
## Calc

How do you integrate sin²x?

*asked on February 2, 2011* -
## math

the edges of a cube are 3 inches long. what is the surface area, in square inches, of this cube?

*asked on November 9, 2008* -
## Ethics in Criminal Justice

The correlativity of rights and duties mean that: A. moral duties override moral rights. B. moral rights override moral duties. C. the existence of moral rights implies duties by which other must abide. D. None of the above. I think the answer is A but not

*asked on May 10, 2014* -
## Ethics in Criminal Justice

Which of the following might help us develop open-mindedness and the virtue of tolerance? A. Recognizing that people have free will. B. Recognizing that moral norms can and often do vary by time and place. C. Developing our own sense of egoism. D. All of

*asked on April 21, 2014* -
## Ethics in Criminal Justice

If we eliminate free will completely, we would also be eliminating: A. the possibility of genetic bases for human behavior. B. The value of modern science. C. Moral responsibility. D. Excuses for criminal conduct.

*asked on April 13, 2014* -
## algebra1

the problem is 5f+7 less than or equal to 22. can anyone please work this out for me and check it for me? and what i mean by checking it is like when you get the answer you check it and make sure its write.

*asked on October 1, 2013* -
## Physics!

Imagine a giant dry-cleaner's bag full of air at a temperature of -31 floating like a balloon with a string hanging from it 15 above the ground. Estimate what its temperature would be if you were able to yank it suddenly back to Earth's surface.

*asked on May 2, 2013* -
## Differential eqns

a) Sketch the phase line for the differential equation dy/dt=1/((y-2)(y+1)) and discuss the behavior of the solution with initial condition y(0)=1/2 b) Apply analytic techniques to the initial-value problem dy/dt=1/((y-2)(y+1))), y(0)=1/2 and compare your

*asked on February 3, 2013* -
## Consumer/Bus Math Sem 1 (Standard)

Pat worked 43 hours and received $7.25 per hour for regular pay and time-and-a-half for all hours over 40 hours. What were her weekly earnings? $22.83 $322.63 $269.75

*asked on December 18, 2012* -
## statistics

a mean score on a standardized test is 50 with a standard deviation of 10. What are the following: 1. what scores fall between -1 and +1 standard deviation? 2. what percent of all scores fall between -1 and +1 standard deviation? 3. what score falls at +2

*asked on May 11, 2012* -
## Math

Nico was stunned when he opened the mail. Here was a check for $322.50! This was the interest he earned on his investment. One year ago Nico had been given $5,000. His parents made him put it in the bank and save it for college, but they said he could keep

*asked on April 16, 2012* -
## Chem

Epsom salts consist of magnesium sulfate heptahydrate. Write its formula. a) How many atoms of oxygen are in 5.15g of Epsom salts? b) How many formula units of the compound are present in 5.15g? c) How many moles of water molecules are in 5.15 g of Epsom

*asked on October 7, 2011* -
## chemistry

at 327 degrees C, the equilibrium concentrations are [CH3OH]=0.15M, [CO]=0.24M, and [H2]=1.1M for the reaction: CH3OH(g)CO(g)+2H2(g) Calculate Kp at this temperature

*asked on February 16, 2011* -
## Physics (Help!)

You throw a glove straight upward to celebrate a victory. Its initial kinetic energy is K and it reaches a maximum height H. What is the kinetic energy of the glove when it is at the height H/2?

*asked on January 9, 2011* -
## Calc

If dy/dx = x²y², then d²y/dx² = ?

*asked on January 2, 2011* -
## Calc

Use implicit differentiation to find dy/dx. ln xy + 5x = 30

*asked on December 2, 2010* -
## Social studies

which of the following best illustrates how a president can use the news media to reach the largest segment of the public? 1. hold a state dinner for foreign dignitaries 2. hold a conference with cabinet members 3. meet with heads of congressional

*asked on March 10, 2019* -
## Probability/Distribution

A catalyst researcher states that the diameters (in microns) of the pores in a new product catalyst she has made have an exponential distribution with parameter ë = 0.25 (35 pts). (a) Determine the mean pore size. (b) Determine the standard deviation of

*asked on October 11, 2016* -
## Engineering Math

Assume that the number of ﬁsh P(t) after t years grows according to the logistic equation dP/dt= P(a-bP) = bP(300 − P) Find the solution of this DE (with the given initial value at t = 0) as a separable equation. Your solution formula will contain b as

*asked on September 27, 2016* -
## Calculus

A 20m ladder is leaning against a wall. Top of ladder is sliding down at 3m per second and the bottom is sliding away from the wall at 4m per second. How high is the top of the ladder and far is the bottom of the ladder from the wall.

*asked on July 23, 2016* -
## chemistry

A student measure 9.43 mL of an unknown liquid in a graduated cylinder. The mass of the empty cylinder is 34.670 g, and the mass of the cylinder and liquid is 44.197 g. What is the density of the unknown liquid? (remember significant figures and units in

*asked on September 14, 2015* -
## math

8 < 5 + y

*asked on July 27, 2014* -
## Ethics in Criminal Justice

The power to make choices and engage in actions that originate with ourselves is referred to as: A. Free will B. Objectivism. C. Determination. D. Predetermination.

*asked on April 13, 2014* -
## algebra

A newspaper carrier has $4.00 in change. He has two more quarters than dimes but five times as many nickels as quarters. How many of coins of each type does he have. This is what I got so far and then I get lost. dimes = x quarters = x+2 nickels = 5(x+2)

*asked on February 12, 2014* -
## Differential Equations

a) Sketch the phase line for the differential equation dy/dt=1/((y-2)(y+1)) and discuss the behavior of the solution with initial condition y(0)=1/2 b) Apply analytic techniques to the initial-value problem dy/dt=1/((y-2)(y+1))), y(0)=1/2 and compare your

*asked on February 3, 2013* -
## science

19. The term chromatin refers to a. the color of certain cells b. chromosomal DNA c. the fluid within the nucleus d. ribosomal RNA

*asked on January 28, 2013* -
## calculus

A fence 8 feet tall stands on level ground and runs parallel to a tall building. If the fence is 1 foot from the building, find the shortest ladder that will extend from the ground over the fence to the wall of the building.

*asked on October 11, 2012* -
## Chemistry

2NaOH+2Al+2H2O --> 2NaAlO2+3H2 here is the reaction. If i am trying to find the mass of hydrogen produced and i am trying to convert .95 moles Al to moles H, which number from the reaction do I use for H when converting from moles to moles? Do I 6 because

*asked on March 9, 2012* -
## Math

the design below grows each day, as shown. if the pattern continues to grow like this, how many tiles will there be in the design on the tenth day? on the fiftieth day? Day 1 1 tile Day 2 5 tiles Day 3 13 tiles

*asked on March 5, 2012* -
## Probability

Assume that P(A) = 0.4, P(B) = 0.4, and P(A∪B) = 0.7. Find P(A∩B) and P(A complement ∩ B complement).

*asked on January 17, 2012* -
## Chem

The field of nanotechnology offers some intriguing possibilities, such as the creation of fibers one atom wide. Suppose you were able to string together 1.00 mol Ag atoms, each of radius 144 pm, into one of these fibers by encapsulating them in carbon

*asked on October 8, 2011* -
## Chemistry

A mixture of gases at 760.0 torr contains 35.0% nitrogen, 22.0% oxygen , and 43.0% carbon dioxide by volume. What is the pressure of the carbon dioxide gas in torr?

*asked on August 19, 2011* -
## Calc

A particle moves along a path described by x=cos³t and y=sin³t. The distance that the particle travels along the path from t=0 to t=π/2 is... Thank you!

*asked on April 25, 2011* -
## Calc

A rectangle is to be inscribed in a semicircle of radius 8, with one side lying on the diameter of the circle. What is the maximum possible area of the rectangle?

*asked on February 22, 2011* -
## Calc

The slope of a curve at each point (x,y) is given by 4x - 1. Which of the following is an equation for this curve if it passes through the point (-2,3)? A) y=4x²-x-15 B) y=x²-4x-9 C) y=2x²-x-7 D) y=2x²-x E) y=2x²-x+7

*asked on January 23, 2011* -
## Calc

y = x^2 y = 6 - x Find the area of the region by integrating (a) with respect to x and (b) with respect to y.

*asked on January 18, 2011* -
## Calc

If y = (cos²x)/(1 + sin x), then dy/dx = ?

*asked on January 18, 2011* -
## health, safety, and nutrition for the young child

a child who moved from throwing a ball using only an elbow movement to throwing a ball using her elbow, wrist, and shoulder is showing signs of _____ development. (a)intertask (b)spatial (c)joint-plate (d)intratask

*asked on January 17, 2011* -
## Anatomy and Physiology

Urine passes from the bladder to the outside of the body through a tube called the .Urethra Muscles are attached to bones by structures called .Tendons Communication, integration, and control are the primary functions of two body systems called and .

*asked on January 12, 2011* -
## 5th grade Math

I have to find the function rule that goes with this table... X Y 2 8 4 18 7 33 9 43 12 57 I've been trying to figure it out for an hour and can't find anything that works for all of them.

*asked on October 27, 2010* -
## Psychology

This is a homework assignment for my Psychology course on Memory and learning. Find a Movie/video clip (1-3 mins)that demonstrate a concept / phenomenom relevant to learning and memory? My prof used Matrix (what we see is just our neuron firing) and Bourne

*asked on March 12, 2009* -
## 3rd grade

The Pilgrims were seeking freedom

*asked on November 18, 2008* -
## Chem

find pH of 0.050 M HCLO4 plus 0.050 M HBr> You must consider activities>

*asked on November 12, 2008* -
## 11th grade

your pet dog runs around in circles, chasing his tail. Does this mean acceleration?

*asked on September 18, 2008* -
## Pre calc

How do you write a quadratic equation in standard form for a given set of zeros?

*asked on August 2, 2008* -
## geometry

what is the area of a rectangle with a width of 12 feet and a length of 10?

*asked on February 12, 2008* -
## pre-calculus

the spread of oil leaking from a tanker is in the shape of a circle. If the radius r (in feet) of the spread after t hours is r(t)= 200 square root of t, find the area A of the oil slick as a function of the time t. You know that the area of a circle is

*asked on October 3, 2006* -
## History

In which world regions or countries was the Seven Years’ War fought? a.)Australia, South America, China b.)North America, Western Europe, India c.)North Africa, Mexico, Japan d.)Scandinavia, Middle East, Afghanistan I think it is B

*asked on July 2, 2020* -
## Social studies

what is the function or purpose of public radio and television in a democratic society

*asked on April 15, 2020* -
## Biology

What is the difference between carbon-13 and carbon-14? A. the number of electrons B. the number of neutrons C. the number of nuclei Please help me and explain the answer and how you got it. I'm really struggling in this class.

*asked on September 26, 2018* -
## Introduction to computers

It is important to plan a document before you create it. List three things you should identify and consider before you plan the layout and design of a document. Why?

*asked on May 16, 2018* -
## Pre algebra

Please help I’m struggling with how to find the percent of change each decade and how to predict a future price. I can’t find any examples of this lesson for help Directions: You probably see them in the news all the time—predictions about prices,

*asked on December 8, 2017* -
## Math

Suppose that license plates in a certain country are made up of three letters followed by 2 digits followed by 3 more letters. How many license plates can be made if no repetitions are allowed within each set. (That is, no repetition within the first set

*asked on November 4, 2017* -
## math

A card is selected from a deck. Find the following probabilities. A standard deck of cards has 52 Cards. There are 13 values and 4 suits. Suits are Spades, Clubs, Diamonds and Hearts. Each suit has 13 cards. There are 3 face cards Jack, Queen, and King. a

*asked on July 3, 2017* -
## Algebra

How much weight will a 4 I ch wide 4 inch high and 216 inches long beam support

*asked on March 5, 2017* -
## Cal 3

Find critical points for f(x,y)= x^3+y^3-15x^2-6xy+18y^2+39x+138y I know you first take the partial derivative of x and y, but I am not sure where to go from there.

*asked on December 6, 2016* -
## Engineering Linear Equation

At your initial meeting with your business partners for CellGenTech, you propose that the rate of change in the number of newly introduced cell lines that the company scientists should be able to produce should be proportional to the number of cell lines.

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

A tank holds 52.9 cm3 of water. What is the volume in in3? (2.54 cm=1 in, Remember significant figures, but this answer does not need units, since the answer must be in in3)

*asked on September 14, 2015* -
## chemistry

How many inches are in 2.41 m? (2.54 cm = 1 inch, remember significant figures and units)

*asked on September 14, 2015* -
## mat

Becky used 5 teaspoons of mustard to make a 32 ounces of potato salad. How many teaspoons of mustard does she need to make 4 pounds of potato salad?

*asked on December 5, 2014* -
## Trig

a ships navigator determines that the ship is moving through the water at 17.5mi/h with a heading of 26.3 degrees north of east but the ship is actually moving at 19.3 mi/h in a direction of 33.7 degrees north of east. What is the velocity of the current?

*asked on December 1, 2014* -
## Ethics in Criminal Justice

The correlativity of rights and duties means that: A. moral duties override moral rights. B. moral rights override moral duties. C. the existence of moral rights implies duties by which others must abide. D. None of the above. I think it's B. Am I right?

*asked on May 8, 2014*