# Sophia

Most popular questions and responses by Sophia-
## Math (Calculus Optimization)

An oil field contains 8 wells, which produce a total of 1600 barrels of oil per day. For each additional well that is drilled, the average production per well decreases by 10 barrels per day. How many additional wells should be drilled to obtain the

*asked on June 27, 2017* -
## Math

List out the elements of the set "The letters of the word Mississippi"

*asked on October 1, 2014* -
## Math 6

n ice cream stand sells chocolate, vanilla, and strawberry ice cream as well as a choice of 22 toppings. How many choices are there for a single flavor of ice cream with one topping? How do I do this? is it 46 choices? Am I right?

*asked on May 10, 2014* -
## Organic Chemistry

If fructose, glucose, and sucrose are the only carbohydrates in honey, how could you use Benedict's reagent to determine the number of moles of sucrose in a 1.0g sample of honey?

*asked on March 8, 2011* -
## Physics

About how much pressure do the feet of a 6000-kg elephant exert on the ground? Assume each foot has area of 0.10 square meters.

*asked on February 20, 2011* -
## Chemistry

1. A student collected the following data for a fixed volume of gas: Temperature (⁰C) Pressure (mm of Hg) 10 726 20 750 40 800 70 880 100 960 150 ??? Fill in the missing data point. Show all calculations leading to an answer.

*asked on December 28, 2016* -
## Phyics

Bob heads out into a lake at an angle of 41◦ with respect to the shore. If his boat is capable of a speed of 1.7 m/s, how far from land will he be in 7 min and 17 s ? Answer in units of m.

*asked on October 15, 2016* -
## Math

the population of new york city doubles during the workday. at the end of the workday, the population decreases by half. if the population in new york city is roughly 4,000,000 people before rush hour, and morning rush hour lasts 3 hours. what would be the

*asked on September 9, 2018* -
## math

Carlita saw 5 times as many robins as cardinals while bird watching. She saw a total of 24 birds. How many more robins did she see than cardinals

*asked on November 7, 2016* -
## Physics

The equation y=5 sin(3x-4), where y is in mm, x is in m and t is in secs, represents a wave motion. Determine the frequency, period and speed of the wave

*asked on February 26, 2018* -
## physics

An airplane traveling 1001 m above the ocean at 125km/h is going to drop a box of supplies to shipwrecked victims below. What is the horizontal distance between the plane and the victims when the box is dropped?

*asked on January 25, 2009* -
## Biochemistry 105

8. Arrange the following molecules in the order of increasing polarity. a. (PH3, HCl, H2O, CCl4) b. (NH3, HF, H2O, HBr)

*asked on February 12, 2017* -
## Social studies

Why did the English build Fort King George in 1721? as a key trading center for its valuable furs.*** to prevent Spanish and French attacks. as a key entrance to the Northwest Passage. to stop the spread of disease from the west.

*asked on September 24, 2019* -
## Chmistry

Write a balanced chemical equation for the combustion of acetylene if the products are: a) Carbon and water vapour b) Carbon monoxide and water vapour c) Carbon, carbon dioxide. Carbon monoxide and water vapour d) The complete combustion of acetylene

*asked on March 28, 2016* -
## Statistics

A manufacturer makes two models of an item: model I, which accounts for 80% of unit sales, and model II, which accounts for 20% of unit sales. Because of defects, the manufacturer has to replace (or exchange) 10% of its model I and 18% of its model II. If

*asked on October 4, 2007* -
## Chemistry

“1.25 g of crushed limestone was added to 50.0 cm3 of 1.00 mol dm-3 hydrochloric acid (an excess). The mixture was left until all bubbling stopped and was then made up carefully to 250 cm3 with pure water. A 25.0 cm3 sample of this was pipetted into a

*asked on November 10, 2010* -
## Algebra

A baker bakes a batch of muffins and splits the batch evenly onto six different trays. She then adds five croissants to each tray. If each tray now contains at least twenty baked goods, what is the least possible number of muffins in the baker's original

*asked on May 25, 2015* -
## Math

A textbook weighs 2.5 pounds.How many kilograms does the textbook weigh? Round your answer to the nearest tenth of a pound. 1kg =2.2 lb - - Helllpp

*asked on November 30, 2018* -
## Physics

What is the mass of the air in a room that has dimensions of 10m x 30m x 4m?

*asked on February 20, 2011* -
## math

Three softball teams ordered equipment from the same catalog. The first team spent $285 on 5 shirts, 4 caps, and 8 bats. The second team spent $210 on 12 shirts and 6 caps. The third team spent $250 for 7 shirts, 10 caps, and 3 bats. What were the catalog

*asked on January 30, 2017* -
## Physics

The Olympic record for the marathon set in 2008 is 2 h, 6 m, 32 s. The marathon distance is 26 mi. What was the average speed of the record-setting runner in km/h?

*asked on September 6, 2016* -
## math

When an airplane experiences drag, are the forces added or subtracted? Hint: Drag is the term used to describe the air in front of the plane pushing the airplane backwards.

*asked on October 2, 2018* -
## Physics

A person walks 21 m East and then walks 34 m at an angle 32◦ North of East. What is the magnitude of the total displacement? Answer in units of m.

*asked on October 15, 2016* -
## English

The school’s policy against girls wearing leggings is undemocratic. Our clothing is an expression of who we are. Limiting our choices is the same as limiting our right to express ourselves. We must be assertive in fighting for our rights. Which synonym

*asked on July 8, 2019* -
## Math: Probability

A bag has 2 red marbles, 1 blue marble and 4 gold marbles. What is the probability of drawing two gold marbles, if the first marble is replaced after it is drawn? is it 16/49 or 7/13

*asked on April 28, 2019* -
## Chemistry

Which of the following is true about oxidation reactions? A. Oxidation reactions are the principal source of energy on Earth. B. All oxidation reactions are accompanied by reduction reactions. C. The burning of wood in a fireplace and the metabolization of

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

Leena bakes a loaf of bread. She eats 1/8 of the loaf and gives 1/6 of it to each of her 3 friends. What fraction of the loaf of bread is left?

*asked on February 8, 2015* -
## Information Technology

Develop an algorithm, flow chart and pseudocode that accept as input three unit test scores and a project score for seven students. The algorithm, flow chart and pseudocode should accept seven examination scores. The students's overall score comprised of

*asked on October 23, 2012* -
## Precalculus

cotx-cos^(3)xcscx

*asked on October 22, 2012* -
## Math

A math problem asks when two brothers will have saved the same amount of money. When Marta writes and solves the equation, her final step is 3 = 7. Assuming Marta has done everything correctly, how should she interpret this solution? A. The brothers

*asked on August 29, 2019* -
## Physics

What is the direction of this resultant vector (between the limits of −180◦ and +180◦ from the positive x-axis) ? 1. −88◦ 2. −117◦ 3. −144◦ 4. −143◦ 5. −135◦ 6. −171◦

*asked on October 15, 2016* -
## physics

A pitched ball is hit by a batter at a 45-degree angle and just clears the outfield fence, 98 m away. If the fence is at the same height as the pitch, find the velocity of the ball when it left the bat. Ignore air resistance.

*asked on January 25, 2009* -
## Precalc

suppose you want to invest $60,000 for ten years. You can invest your money in a CD that earns 4% interest, compounded quarterly and has no risk, or you can invest your money in futures that ear 10% interest, compounded quarterly. However, the second

*asked on November 5, 2015* -
## Chemistry

A plasma reaction converts A (Molecular weight = 200) to B and uses NAD as a co-substrate and produces NADH as a by product (1 mole of NADH is produced per every 1 mole of A converted to B). The amount of NADH can be determined by monitoring its’

*asked on December 14, 2016* -
## Algebra

Suppose you want to enclose a rectangular garden plot against a house using fencing on three sides, as shown at the left. Assume you have 50 ft. of fencing material and want to create a garden with an area of 150 ft². A. Let w = the width. Write an

*asked on December 1, 2015* -
## Math

The media center at Josh's school has a computer area. The first 4 rows have 6 computers each. The fifth row has 4 computers. How many computers are there?

*asked on October 27, 2018* -
## Math

Alan scored a total of 14 points for answering all the 15 questions on a math quiz. For every correctly answered question, Alan got 2 points. For every wrong answer, he lost 2 points. How many questions did he answer correctly?

*asked on March 11, 2015* -
## Pre calc- confused

Geometry/Maximum area: A rancher wants to enlarge an existing rectangular corral such that the total area of the new corral is 1.5 times that of the original corral. The current corral's dimensions are 250 feet by 160 feet. The rancher wants to increase

*asked on October 15, 2015* -
## Chemistry

How much SO2 is needed to saturate 50g of H2O at 5 degrees Celsius

*asked on April 27, 2015* -
## Math: Probability

My locker combination has three digits. None of the digits are zero. What is the probability that the first digit of my locker combination is less than 4? A) 3/10 B) 1/3 C) 2/5 D) 4/9

*asked on April 28, 2019* -
## SCIENCE

PISTILS AND STAMENS REACH MATURITY AT DIFFERENT TIMES, WHY WOULD THIS BE AN ADVANTAGE TO THE PLANT?

*asked on April 1, 2008* -
## human biology

if a cell lacks ATP, which of the following processes would cease to operate immediately? diffusion Na+/K= pump facilitated diffusion osmosis or passive transport

*asked on March 18, 2007* -
## Utah state history

1. The contributions of the mountain men include... A: developing first Anglo- American settlements B: establishing good relations with the Native Americans C: developing local resources D: establishing routes through the region for others to follow

*asked on February 14, 2018* -
## Chemistry

The solubility of CaCO3 at 25 degrees celsius is 6.90*10-5M. The reaction is CaCO3(s)-->Ca 2+(aq) + CO3 2-(aq)

*asked on February 13, 2008* -
## Math: Probability

A bag has 2 red marbles, 1 blue marble and 4 gold marbles. What is the probability of drawing two gold marbles, if the first marble is replaced after it is drawn?

*asked on April 28, 2019* -
## math

a set of five positive integers has a mean median and range of 7 how many distant sets whose members are listed from least to greatest could have these properties

*asked on July 2, 2014* -
## science

6. identify the action-reaction pairs of forces for the following situations: (a) you step off a curb. (b) you pat your tutor on the back (c) a wave hits a rocky shore.

*asked on February 3, 2011* -
## Math riddle PIZZAZZ Worksheet

What happened to the grocer who stacked all of the liquid detergent no the high shelf? plzzz help

*asked on October 30, 2008* -
## Math

A female grizzly bear weighs 500 pounds. After hibernating for 6 months, she weighs only 200 pounds. What is the mean change in weight per month?

*asked on September 4, 2018* -
## physics

A small dog is trained to jump straight up a distance of 1.2 m. How much kinetic energy does the 7.2-kg dog need to jump this high? (The acceleration due to gravity is 9.8 m/s2.) Show your work for credit.

*asked on February 5, 2017* -
## Math

What is the equation of the line that passes through the points (15, 9) and (-2, 9)? It doesn't give me options.

*asked on October 4, 2019* -
## Physics

A superhero flies 185 m from the top of a tall building at an angle of 15◦ below the horizontal. What is the horizontal component of the superhero’s displacement? Draw the vectors to scale on a graph to determine the answer. Answer in units of m. Your

*asked on October 16, 2016* -
## Math

The distance on a bike path between Westfield and Southborough is 46 mi. Tracey leaves Westfield heading to Southborough cycling at a constant rate of 15 mph. Emma leaves her house at the same time and cycles along the same path from Southborough to meet

*asked on August 26, 2019* -
## Math

The community raised twice the amount of money needed to buy a piece of land for the playground, with a given area. Jon and his dad decided to multiply the length and the width of the planned playground by 2. If the cost of the land is proportional to the

*asked on September 5, 2019* -
## Math

In math class, a student has an average grade of 85% for five tests so far. What grade must that student earn on the next test to reach an average grade of 90% for all six tests?

*asked on December 1, 2016* -
## Physics

Thank you Damon for answering my other question.. I appreciate... The distance between two successive crests of a water wave travelling at 3.6m/s is 0.45m. Calculate the frequency of the wave?

*asked on February 26, 2018* -
## Physics

A truck travels beneath an airplane that is moving 150 km/h at an angle of 34◦ to the ground. How fast must the truck travel to stay beneath the airplane? Answer in units of km/h.

*asked on October 15, 2016* -
## physics

A mass of 135 g of an element is known to contain 30.1 1023 atoms. What is the element? hydrogen oxyden aluminum carbon Is it aluminum?

*asked on April 26, 2008* -
## Math

A package of spaghetti weighs 266 grams. ow many ounces does the package weigh? 1 oz = 28 g

*asked on December 5, 2018* -
## Reading

What is a preposition? What is the preposition in this sentence? "Sally read her book in the living room."

*asked on April 26, 2018* -
## Math

On Friday, Dale and Lindsay each spent $5.00 on trading cards, and they each bought one package of chewing gum. On Saturday, Lindsay and her three sisters each spent $2.00 on trading cards, and each girl bought one package of gum. Lindsay noticed that the

*asked on August 29, 2019* -
## Math

Mrs. Greenaway has decided to open a new preschool in her town. To decide whether she will have enough students to be successful, she hires a researcher to conduct a survey of the town’s population. Which of the following groups would make up the best

*asked on October 9, 2019* -
## Math

Tally Lake is 11.25 miles long. Mary starts at one end and kayaks toward the other end, paddling at a constant rate of 2.5 miles per hour. At the same time, Ann starts out from the opposite end and paddles toward Mary at a constant rate of 2 miles per

*asked on August 26, 2019* -
## World History

List two ways the Atlantic Slave trade affected Africa.

*asked on July 26, 2009* -
## Social Studies

Why is Texas referred to as the Lone Star state? I think it is because of the flag has one star I just dont know if that is right.

*asked on May 13, 2019* -
## Math

A locker combination has three nonzero digits, and digits cannot be repeated. If the first digit is 3, what is the probability that the next digit is odd? A.4/9 B.1/5 C.1/2 D.5/9

*asked on April 28, 2019* -
## Math

here is the question: Freida must take a 4-hour exam containing 200 questions, 50 of which are math. Twice as much time should be allowed for each math ques as for each other type of question. What is the total # of minutes she should allow for the math

*asked on November 12, 2009* -
## Math: Probability

Jake rolls two number cubes. What is the probability that both numbers are greater than 4?

*asked on April 29, 2019* -
## Math

If m∠CBD = 148°, what is m∠ABE

*asked on April 9, 2019* -
## Math

A jar contains 5 orange marbles, 3 black marbles, and 6 brown marbles. Event A = drawing a brown marble on the first draw Event B = drawing an orange marble on the second draw If two marbles are drawn from the jar, one after the other and not replaced,

*asked on October 5, 2019* -
## Math

Can anyone help me with 2(y+2)for Y=2

*asked on December 9, 2018* -
## World Regional Studies/ Geography

In January 2000, cyanide is released to the Tisza River in Hungary. Effect 1: Effect 2: Water Pollution Countries develop industries. Effect 1: Effect 2: Poland’s water in most rivers is unsafe to drink Rain washes fertilizers from fields into bodies of

*asked on October 16, 2014* -
## Math

Michelle is interested in knowing how often girls in her class at school use their cell phones to instant message their friends. Which of the following methods could Michelle use to conduct a simple random sample to answer her question? A. Give the survey

*asked on October 8, 2019* -
## Physics! Case II

A woman at an airport is pulling her 25.0 kg by a strap at an angle of 25 ° above the horizontal as shown in figure Fig. P5.44. She pulls on the strap with a 45.0 N force, and friction is negligible. What is the acceleration of the suitcase? ___m/s^2

*asked on December 3, 2012* -
## Math

Find the distance from the point to a. the originb. the z-axis. I’d be very glad if you could help me

*asked on November 29, 2018* -
## Poetry

In poetry what are regular and irregular lines?

*asked on April 26, 2018* -
## PHYSICS URGENT! PLEASE FRICTION CASE 2

A 13 kg box is at rest on a level floor. The coefficient of static friction µS = 0.9 and the coefficient of kinetic friction µK = 0.8. Audrey is applying a 140 N push at an angle (=20°) as shown in Figure 1. C) What is the magnitude of FNormal on box

*asked on December 4, 2012* -
## Math

A wallet contains 3 dimes, 6 pennies, and 6 nickels. Event A is defined as drawing a dime on the first draw, and event B is defined as drawing a dime on the second draw. If Jack draws two coins from the wallet, one after the other without replacement, what

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

Dello, i need help with this problem. Find the periodic withdrawals PMT for the annuity given. HINT [See Example 4.] (Assume end-of-period withdrawals and compounding at the same intervals as withdrawals. Round your answer to the nearest cent.) $100,000 at

*asked on March 2, 2018* -
## math

The value of a car decreases at a constant rate as it grows older. When the car is 2 years old, it is worth $23,000. When the car is 5 years old it is worth $15,500. Write and equation relating y (value of the car $) to x (age of car).

*asked on October 22, 2016* -
## Math

Marsha purchased a chair that was originally $699. The chair was on sale for 13 off. Marsha signed up for the store’s credit card and received an additional 10% off the sale price. What was the cost of the chair after the discounts?

*asked on August 26, 2019* -
## Math

A locker combination has three nonzero digits, and digits cannot be repeated. If the first two digits are even, what is the probability that the third digit is even? A) 7/9 B) 1/3 C) 1/6 D) 1/7

*asked on April 28, 2019* -
## Math

Given A = (7, 1, 3), C = (4, -2, 3), B = (5, 1, 2), and D = (6, m, n), find m and n so that segments BD and AC have the same midpoint. Is ABCD a parallelogram? Explain. Please help! I’d be very thankful

*asked on November 29, 2018* -
## Maths

An amount of money is shared by three people in the ratio 2 : 5 : 8. What fraction of this money is given to the person who receives the smallest share?

*asked on August 17, 2016* -
## Math

How can you use decimal squares to represent the product 0 * 0.7?

*asked on December 9, 2014* -
## math

A portrait of George Washington is square and has an area of 169 square centimeters. How long is each side of the portrait?

*asked on September 14, 2013* -
## Math

Darla and Dave leave school each day at 2:00 P.M. on their bikes and travel in opposite directions. If Darla rides at a constant rate of 12 kilometers per hour and Dave rides at a constant rate of 14 kilometers per hour, after how many hours are they 65

*asked on August 26, 2019* -
## Math: Probability

A locker combination has three nonzero digits, and digits cannot be repeated. If the first two digits are even, what is the probability that the third digit is even?

*asked on April 29, 2019* -
## Social Studies

Do you know any facts or websites for Helen Keller

*asked on April 24, 2019* -
## math

The value of a car decreases at a constant rate. After 1 year the value of the car is $20,000. After 2 more yearsit is $14,000. Write an equation in slope-intercept that represents the value y (in dollars) of the car after x years.

*asked on October 22, 2016* -
## math

Find the number of ways in which 9 people can be divided into 2 groups: the first group has 5 people and the second group has 4 people.

*asked on April 15, 2018* -
## MATH HELP PLEASE I HAVE NEVER BEEN MORE CONFUSED

The value of a car decreases at a constant rate. After 1 year the value of the car is $20,000. After 2 more yearsit is $14,000. Write an equation in slope-intercept that represents the value y (in dollars) of the car after x years.

*asked on October 22, 2016* -
## Math

Using the break apart method what is the best way to multiply 8x7

*asked on September 9, 2015* -
## math

The value of a car decreases at a constant rate as it grows older. When the car is 2 years old, it is worth $23,000. When the car is 5 years old it is worth $15,500. Write and equation relating y (value of the car $) to x (age of car). Is it

*asked on November 7, 2009* -
## Math

A 7th grade student wants to find our which subject is the most popular subject among the 120 students in her grade. She decides to use an alphabetical list of student names from which to choose her sample. Which of the following is an example of a sample

*asked on October 8, 2019* -
## Math: Probability

A bag has 2 red marbles, 1 blue marble and 4 gold marbles. What is the probability of drawing two gold marbles, if the first marble is replaced after it is drawn? C. 4/7 D. 7/13 ( I didn't add A or B `cause i knew those were wrong)

*asked on April 28, 2019* -
## math

24 How many 5-letter “words” can be formed from the letters of the word FORMULATED, if each must contain 2 vowels and 3 consonants? How many of these will have the vowels at the two ends on the “word”?

*asked on April 15, 2018* -
## Math

The median number of magazine appearances made by 7 models is 5. The range of number of magazine appearances by those models is 5. Determine if the following statement is true, is false, or does not contain enough information. At least one of the models

*asked on October 14, 2017* -
## Math

1. the points given are two of the 3 vertices of a right triangle. Which could be the third vertex of the triangle given 2 points are (-4,-5) & (3,2) ? 2.) A circle with center O and radius r is intersected at 2 distinct points by line l. Which is true? a.

*asked on November 9, 2015* -
## Biology

Good afternoon, Could you help me find environmental factors that would influence biodiversity. Thanks for your time.

*asked on May 19, 2009*