# David

Newest questions and responses by David-
## Chemistry

What is the percentage composition of water in a sample of SrS2O3 plus 5 H2O? (this is a hydrate)

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

What happened to the settlement on Roanoke Island?

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

Consider a Bernoulli process with parameter p=1/3. Let T1 be the time of the first success and let T1+T2 be the time of the second success. We are told that the results of the two slots that follow the first success are failures, so that XT1+1=XT1+2=0.

*asked on November 28, 2018* -
## math

a square based brass plate is 2mm high and has a mass of 1.05 the density of the brass is 8.4g/cubic cm.calculate the length of the plate in cm

*asked on November 28, 2018* -
## probability

et X and Y be independent Erlang random variables with common parameter λ and of order m and n, respectively. Is the random variable X+Y Erlang? If yes, enter below its order in terms of m and n using standard notation. If not, enter 0.

*asked on November 27, 2018* -
## probability

The consecutive interarrival times of a certain arrival process are i.i.d. random variables that are equally likely to be 5, 10, or 15 minutes. Find the expected value of the length of the interarrival time seen by an observer who arrives at some

*asked on November 27, 2018* -
## probability

Consider an arrival process whose interarrival times are independent exponential random variables with mean 2 (and consequently variance equal to 4), and consider the interarrival interval S seen by an observer who arrives at a fixed time t∗, as in the

*asked on November 27, 2018* -
## Chemistry

The total volume of the Rogers Center is 1.6 x 10^6 m cubed. If the volume of 100 peas is about 55 cm cubed, how many Rogers Centers would 6.02 x 10^23 peas fill?

*asked on November 18, 2018* -
## Math

Cora's Bike Shop charges $16 per hour to rent a bicycle and a helmet. Dave's Bike Shop charges $11 per hour for the bike and a flat fee of $5 for the helmet rental. For what number of hours are the total charges at both bike shops the same?

*asked on November 14, 2018* -
## Math

in a survey of 290 newspaper readers, 181 of them read the Daily Times, 142 Read the Guardian 117 read punch and each reads at least one of the three papers if 75 read the Daily Times, and the Guardian, 60 read the Daily Times and punch, and 54 read the

*asked on November 11, 2018* -
## Algebra

Marisa is decorating a rectangular prism with a height of 2 ft, width of 1 ft, and length of 3 ft. Each tile costs $0.79. How much will it cost Marisa to tile the outside of the whole prism?

*asked on November 8, 2018* -
## Math

A cone is 3 inches high and has a base with a surface area of 7 square inches. What is the volume of the cone? I thought the correct formula to use was 1/3(3.14)(r)^2(3), but not getting the correct answer. Please help.

*asked on October 19, 2018* -
## PHYSIC

A train has an initial velocity of 44m/s-2 and acceleration of 4m/s-2 velocity after 10s is

*asked on October 17, 2018* -
## PHYSIC

A body accelerate uniformly from rest at 2ms-2 .calculate it,s velocity after travelling 9m

*asked on October 17, 2018* -
## math

The equation y = 12x describes the amount of money Louis earns, where x is the number of hours he works and y is the amount of money he earns. The table shows the amount of money Carl earns for different numbers of hours worked. Carl’s Earnings Time (h)

*asked on September 19, 2018* -
## algebra

if the gym charges a registration fee of $60.00 and a membership fee of $20.00 per month. and the manager waived the registration fee for 50 random people. write a expression to represent how much money the gym will make. after 6 months how much money will

*asked on September 10, 2018* -
## algebra

Tom decided to join Platinum Gym because of its new equipment. At the grand opening, the manager announced that 124 people had signed up for gym membership. As part of the grand opening event, the manager waived the registration fee for 50 random people.

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

1. the diameter of a carbon atom is 0.000 000 000 000 154 m. what is the number expressed in the scientific notation? a) 1.54x10^12m b) 1.54x10^-12m c) 1.54x10^10 d) 1.54x10^-10 2. what is the result of multiplying 2.5x10^10 by 3.5x10^-7 a) 8.75x10^-3 b)

*asked on August 31, 2018* -
## chemistry

1. the diameter of a carbon atom is 0.000 000 000 000 154 m. what is the number expressed in the scientific notation? a) 1.54x10^12m b) 1.54x10^-12m c) 1.54x10^10 d) 1.54x10^-10 2. what is the result of multiplying 2.5x10^10 by 3.5x10^-7 a) 8.75x10^-3 b)

*asked on August 30, 2018* -
## Social Studies

Which of the following correctly pairs a branch of the U.S. government and its power? 1. A. legislative: interprets laws B. executive: makes laws C. executive: enforces laws---- D. judicial: enforces laws 2. Which of the following is an example of the

*asked on August 27, 2018* -
## US History

Which of the following results of the French and Indian War was a cause of the American Revolutionary War? Native Americans lost large amounts of territory. Britain incurred a large debt as a result of the war. France ceded land in Canada and east of the

*asked on June 22, 2018* -
## World history

Which statement describes the relationship between the Russian Orthodox Church and Russian rulers?

*asked on June 5, 2018* -
## Calculus

Show that the function F(x) = integral[x to 3x](1/t)dt is constant on the interval (0, +∞).

*asked on May 16, 2018* -
## Geography

Wallace Creek has been offset by 130.0 meters (430 feet) to the right along the fault. The age of stream deposits indicates that this offset began 3700 years ago. Based on these figures, calculate the average rate of movement along this segment of the

*asked on May 3, 2018* -
## Chemistry

What is the mass of radon if its density is 9.73 g/l at stp

*asked on May 3, 2018* -
## Calculus

Find dy/dt at x = 1 and y = x2 + 3 if dx/dt = 4 I'm not sure how to set up this type of equation. Do you use the pythagorem theorem for this? Then take the derivative, and then plug in?

*asked on April 14, 2018* -
## Math

3. If the banks returned all the money plus interest accumulated from 1938 to 1998 it could be calculated using A=A0 (1.05)^t where A is the amount of money to be returned A0 was the initial amount and t is the number of years since 1938. (Notice that this

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

2. Growth function P=100 (645)^t/21 where P represents the cane toad population and t represents the time measured in months from when the toad was introduced in July 1935. A. What was the initial population of cane toads introduced into Australia? B. What

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

1. You gathered data and realized that the temperature drop followed the function T=85 (0.3)^t/2 where T is the temperature in Celsius and t is the time in hours the water was left out for. A. What was the initial temperature of the water when it was

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

Sales of a video game released in the year 2000 took off at first, but then steadily slowed as time moved on. The table below shows the number of games sold, in thousands, from the years 2000–2010. Year 2000 2001 2002 2003 2004 2005 Number Sold

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

Due to advances in medicine and higher standards of living, life expectancy has been increasing in most developed countries since the beginning of the 20th century. The table below shows the average life expectancies, in years, of Americans from

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

experiment to demonstrate that expired air contains carbondioxide

*asked on April 2, 2018* -
## international relations

what are the conflict resolutions of the chechens people?

*asked on March 16, 2018* -
## Discrete Mathematics

Most versions of Pascal allow variable names to consist of eight letters or digits with the requirement that the first character must be a letter. How many eight-character variable names are possible? I know that there are 2^7 ways to arrange letters and

*asked on March 10, 2018* -
## Math

I need someone to show me or help with the steps of this problem: Bert received a commission of $247.50. If he works for 15% commission what price of the car did he sell? Thank you in advance to whoever helps me

*asked on March 9, 2018* -
## Discrete Mathematics

Prove (A1 + A2 +...+ An)^T = A1^T + A2^T +...+ An^T using Mathimatical Induction.

*asked on March 7, 2018* -
## Trig

Explain how to find the reference angle of 1406 degrees. Find the reference angle. The reference angle is 34 but how do you get that?

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

How many radians are in a full rotation around a circle or 360 degrees. Help plz!

*asked on February 28, 2018* -
## intro to court suystems

Community prosecution stresses the need for the prosecutor to reach out to the community, but what does “community” mean? Is this reform based on a naïve assumption that all members of the same geographic entity share similar views? How might

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

After the middle of the 18th century, what options did Indians still have in responding to the encroachment of settlers? How had Indian behavior changed since the Iroquois mourning wars of the 17th century?

*asked on February 22, 2018* -
## Math

Two number cubes are rolled- one blue and one yellow. Find the probability that the blue cube is less than 3 and the product is 8. a) Is this event independent or dependent? Explain why. b) Find the probability that the blue cube is less than 3 and the

*asked on February 21, 2018* -
## Math

A baker is decorating the top of around cake with cherries. The diameter of the cake is 9.5 inches. Each cherry is 0.75 inches in diameter. About how many cherries will the baker need to decorate the perimeter of the top of the cake?

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

on tuesday evening randy spent 18 more minutes working on his math homework than he spent working on his philosophy readings. If he spent a total of 126 minutes on those two subjects then how much time did he spend on his math homework?

*asked on February 13, 2018* -
## Math

A circular dog bed has a circumference of about 72 inches. What is the diameter in inches of the dog bed to the nearest inch?

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

Wallace has a $500 budget for a pizza party. Pizza pies cost $12 each. He will also purchase drinks for $30, paper plates for $15 and napkins for $6. Write and solve an inequality that shows how many pizza pies Wallace can purchase.

*asked on February 4, 2018* -
## Calc III

find a vector that makes the same angle with respect to the y-axis that vector i + 3k makes with respect to the x-axis

*asked on January 25, 2018* -
## Physics

A man holds a child on his shoulder while watching a football match.how much work is done if the game lasts for 2hours

*asked on January 18, 2018* -
## mathematics

a town has a population of 8400 in 1990. Fifteen years later, it's population had grown to 12 500. Assuming that the population continues to grow at the same exponential rate, when will the population reach 20 000? Please help im trying to answer this

*asked on January 7, 2018* -
## science;chem

The hydrolysis of ethyl acetate (CH3COOC2H5) by sodium hydroxide yields ethanol (C2H5OH) and sodium acetate (NaO2CCH3) by the reaction shown, which follows second order kinetics. In an experiment 500 mL of 0.1 M ethylacetate in water is mixed with 500 mL

*asked on December 16, 2017* -
## physics

On planet Seeturn, the free fall acceleration is 9.800 N/kg but there is also a strong downward electric field that is uniform close to the planet's surface. A 2.00 kg ball having a charge of 5.00 micro C (5.00*10-6) is thrown upward at a speed of 20.1

*asked on December 7, 2017* -
## MATH!!!

I tried to multiply the equation by a then b then c... I don't know please help by showing the steps I am very lost Determine a+b+c 25/84=1/a+1/an+1/abc

*asked on December 5, 2017* -
## math gr 10

Jordan invests $100 and doubles her money in 8 years. Which operation illiterates the correct use of the rule 72 to estimate the annual interest rate 72x8 8+72x8 72/100 100/8 I put 8+72x8 is that right??

*asked on November 26, 2017* -
## gr 10 math

in a survey 144 people, 83 people said they liked eggs, 65 people said they liked toast, 30 said they liked neither. how many people like both? a 34 b 71 c 18 d 114

*asked on November 26, 2017* -
## Maths

A student spent 2 /9 of his pocket money on beverage and 1 /4 on books. What? fraction

*asked on November 14, 2017* -
## Chemistry

If one 5 mL dose of Milk of Magnesia contains 400 mg of magnesium hydroxide, calculate the concentration of magnesium hydroxide in mol/L.

*asked on November 12, 2017* -
## math

Write the equation of the line that has the following: Contains point (5,3) and is parallel to y = 6x – 5 ------------------------- ---------------------------- The slope is 6 and the y intercept is 27 right?

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

Write the equation of the line that has the following Contains point (3,6) and is perpendicular to y = 2x + 4 --------------------------------------------------- I got that the slope was -1/2 but is the y-intercept really 15/2? can you even have this as a

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

Bob has a helicopter and from the launch pad he flies the following path. First he travels from the launch pad a distance of 52 kilometers at heading 79 degrees South of West. Then he flies 26 kilometers heading 22 degrees north of East. After this he

*asked on October 10, 2017* -
## dbs

Determine the rate of interest at which a sum of money will become 216/125 times the original amount in 1 and a half years, if the interest in compounded half

*asked on September 24, 2017* -
## History

What are the “Rentier States” and why do the oil-producing countries in the Middle East qualify as rentier states?

*asked on September 21, 2017* -
## Mathematics

The height in metres of the water in a harbour is given approximately by the formula d=6+3cos30t, where t is the time in hours from. Find a) The height if the water at 9:45pm b) The highest and the lowest water level and occur

*asked on September 20, 2017* -
## Math

I have 20 tens. I have 3 times as many ones that I have tens. What number am I?

*asked on September 19, 2017* -
## MATH

HOW MUCH PETROL IS NEEDED TO TRAVEL88 KM

*asked on August 22, 2017* -
## chemistry

what are the electrolytes in ORS?

*asked on August 7, 2017* -
## Angular motion

a car has wheel of radius 0.3m and is traveling at a speed of 36m\s. calculate the angular speed of the wheel

*asked on July 22, 2017* -
## SCHM012

diagram all possible pathways for deexciting from n=4 to n=1

*asked on July 18, 2017* -
## math

Team Alpha had one fourth as many people as team Beta. After 6 people quit team Beta and 12 people were transferred to team Alpha from team Beta, both teams became equal. How many people were there originally on team Alpha?

*asked on July 12, 2017* -
## math

Team one had twice as many workers as team two. The number of workers in team one is reduced by 5 and the number of workers in team two is reduced by 2. How many workers are there in each team now if there are 7 more workers in team one?

*asked on July 12, 2017* -
## math

Three departments of a company employ a total of 1274 people. The second department employs 70 more people than the first one, and the third department employs 84 more workers than the second one. How many people work in each department?

*asked on July 12, 2017* -
## math

Kate used 555 grams of wool to knit a sweater, a hat and a scarf. She used 5 times less grams for the hat than for the sweater. She used 5 grams more for the hat than for the scarf. How many grams of wool did she use to knit each item?

*asked on July 12, 2017* -
## math

The lengths of the sides of a rectangle are in a ratio of 4:7. If the length is 31.5 in., find the width, perimeter and area of this rectangle.

*asked on July 11, 2017* -
## Maths

The ages of a woman and her daughter add to 45, five years ago, the woman is six times her daughters age. How old was the woman when her daughter was born?

*asked on July 6, 2017* -
## calculus

Find the constant a such that the function is continuous on the entire real line g(x)=x^2-a^2/x-a if x doesn't equal a 6 if x=a

*asked on June 25, 2017* -
## Chemistry

What is the percent yield of a reaction that converts 5,0 kg of toluene to 6,02 kg of benzoic acid? 2C6H5CH3 + 3O2 --> 2C6H5CO2H + 2H2O

*asked on June 21, 2017* -
## Maths

A tub is filled in 20mins but there is a leakage in it which can empty the full tub in 1hr in how many minutes can it be refilled

*asked on June 9, 2017* -
## Science

Can you send me to a link that explains how genetic variation and environmental pressures can lead to a change in the characteristics of a population.

*asked on June 4, 2017* -
## MATHS

There are 2000 students in a course. They wrote a mathematics test which was scored out of 40 and then converted to percentage. 1. Draw a flowchart that reads the name, sex and score of each student, and outputs the names of the female students that scored

*asked on May 23, 2017* -
## math

Two circles touch each other. One of the circles has a diameter of 26 cm and the other circle has a diameter of 12 cm. Write down (a) the least distance between the centres of the two circles, ....................................................... cm (b)

*asked on May 19, 2017* -
## Social studies

Why do you think the Canadian government is opposed to Quebec's becoming a separate nation? I don't want someone to tell me can you provide me with a source so I can find the answer

*asked on May 8, 2017* -
## Social studies

Which of the following is no longer allowed in the Atlantic Provinces? A)cod fishing B)fishing C)aquaculture**** D)fish processing Correct?

*asked on May 4, 2017* -
## Math

Four pencils cost $0.60. How many pencils can you buy for $0.45?

*asked on May 4, 2017* -
## Math

If my ladder is 6m long and its foot is 1.5m from a vertical wall how far can the ladder reach up the wall?

*asked on May 1, 2017* -
## History

need help on history question The Gulf of Tonkin incident opened the door to A) Kennedy's assassination B) the Rolling Thunder strategy C) Lyndon Johnson realizing that the military D) could not win the war E) all of these answers are correct

*asked on April 10, 2017* -
## thermochemistry

. Mountain climbers often brew tea by melting snow, which they heats over a stove. Our stove burns butane (C4H10), which has a heat of combustion of -2878 kJ/mol. The temperature of the snow is initially at -20 °C, and we need 80 °C water to brew tea. a.

*asked on April 10, 2017* -
## math

the daily production of two factories A and B are 300 and 200 bottle respectively .2% of the product o f each factory are found to be defective .if 6 defective bottle are randomly selected from a daily production of A and B .find the probability that 4 of

*asked on April 10, 2017* -
## chemistry

A 3.04 g piece of aluminum at 60.0 °C is placed into a “styrofoam cup” calorimeter filled with 150.0 mL of water at 25.0 °C. What is the final temperature of the contents of the calorimeter once thermal equilibrium has been established (everything

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

I was in a camp when i came back from the camp someone said "good exposure though what shoul i say ??

*asked on March 27, 2017* -
## Algebra 1

Consider the function L = 4h where L equals the number of legs on h horses. What would be the domain and range of the function?

*asked on March 24, 2017* -
## Math

Talor is building a birdhouse for his backyard. He needs a piece fo wood that is 8 inches long and 6 inches wide. What is the area of the piece of wood tayler needs

*asked on March 23, 2017* -
## Math

Byron’s house has a roof with dimensions shown. (Roof: 1m Height, 7m Hypotenuses, 12m length) He knows that the average rainfall in his suburb is 30cm per year. Byron would like to install a cylindrical rainwater tank to hold the water that runs off the

*asked on March 22, 2017* -
## Biology

What is one of the outputs or products of respiration? It has to be a four letter word with the second letter being e because it is the hint that my teacher gave us. I couldn't find anything on it. So far I have disocovered is carbon dioxide, water, and

*asked on March 22, 2017* -
## Philosophy

1. For each of the following underlined statements identify any vagueness, semantic ambiguity or syntactic ambiguity in the statement. If the statement is vague, explain why. If the statement is ambiguous, provide at least two alternative interpretations

*asked on March 18, 2017* -
## Social studies

1. Why is mining important to the economy of the United States? Can you link a website where I can find this information more quicker?

*asked on March 13, 2017* -
## Math

theoretically if you roll a number cube 36 times, how many times would you expect to roll the number one? could you also give me explanation? Thank you. and also answer as fast as possible.

*asked on March 13, 2017* -
## Chemistry

In the analysis of a sample of drinking water, a rate of 25.00 mL of the water requires 16.04 mL of AgNO3 to 0.05647 M in order to achieve an end to the Mohr method. What is the concentration of chloride ions in the sample?

*asked on March 9, 2017* -
## Algebra 1

You have decided to get a job to pay for a car to drive. You estimate it will cost you $300 per month to buy and maintain the car. You get a job that pays $9.10 per hour. Write an equation for your pay as a function of the hours worked (Use x for the hours

*asked on March 7, 2017* -
## Algebra 1

You have decided to get a job to pay for a car to drive. You estimate it will cost you $300 per month to buy and maintain the car. You get a job that pays $9.10 per hour. Write an equation for your pay as a function of the hours worked (Use x for the hours

*asked on March 7, 2017* -
## Algebra 1

You have decided to get a job to pay for a car to drive. You estimate it will cost you $300 per month to buy and maintain the car. You get a job that pays $9.10 per hour. Write an equation for your pay as a function of the hours worked (Use x for the hours

*asked on March 7, 2017* -
## Science

1. In paper chromatography, is the substance being tested the solute or solvent? Explain your answer. I think the substance being tested is a solvent. I think this because it is being dissolved to form the ink on the filter paper. 2. A bucket of paint

*asked on March 3, 2017* -
## Chemistry

The volume of 10 ml of H2SO4 solution was diluted 250 ml with distilled water. This resulting solution, 25 ml were neutralized by 10 ml of 0.1 mol/L solution of NaOH. calculate the Molarity of sulfuric acid.

*asked on March 1, 2017*