# Marissa

Newest questions and responses by Marissa-
## Calculus

Find a formula for a function of the form y=bxe−ax with local maximum at (0.5,0.3679). y=

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

Start at 500,crate a pattern that subtracts 4 from each number.Stop when you have 5 numbers

*asked on October 8, 2018* -
## Chemistry

Consider the reaction 2H2O(g) → 2H2(g) + O2(g) ΔH = +483.60 kJ/mol at a certain temperature. If the increase in volume is 42.7 L against an external pressure of 1.00 atm, calculate ΔU for this reaction. (The conversion factor is 1 L · atm = 101.3 J.)

*asked on October 3, 2018* -
## Trigonometry

A scientist has 37 grams of a radioactive substance that decays exponentially. Assuming k=-0.3,how many grams of radioactive substance remain after 9 days.

*asked on April 13, 2018* -
## History

The growing popularity of newspapers, magazines, and books in the United States during the 19th century contributed to which of these? The emergence of a uniquely American literary style The expansion of educational opportunities for women and minorities

*asked on April 3, 2017* -
## math

The position of a bucket falling down a well can be represented by the function h(t)=-16t^{2} where t is time in seconds and h(t) is measured in feet. Based on this function, what is the velocity of the bucket after it has fallen for 4 seconds?

*asked on February 27, 2017* -
## Chemistry

Write the symbol for the elements that fit the following descriptions 1. 10 electrons in each -3 ion 2. 18 electrons in each +2 ion 3. The alkaline earth metal in the third period

*asked on January 18, 2017* -
## Calculus

A rectangular tank with a square base, an open top, and a volume of 4,000 ft cubed is to be constructed of sheet steel. Find the dimensions of the tank that has the minimum surface area. I'm not understanding how to get started and find the

*asked on December 5, 2016* -
## Chemistry

How many moles of hydrogen from when 10 moles of methane react completely?

*asked on November 17, 2016* -
## Chemistry

How many moles of water vapor react to yield 546.234 moles of hydrogen?

*asked on November 17, 2016* -
## Chemistry

Write a conversion factor that could be used to convert between moles of methane and moles of hydrogen

*asked on November 17, 2016* -
## Chemistry

What is the maximum mass of cobalt (II) phosphate that will precipitate from a solution prepared by adding an excess of K3PO4 solution to 100.0 mL of 5.0 M CoCI2? Sorry for all the confusion with different names we are working in a group and its easier to

*asked on November 16, 2016* -
## Chemistry

When coal is burned, the sulfur it contains is converted into sulfur dioxide. This is SO2 is a serious pollutant, so it needs to be removed before it escapes from the stack of a coal fired plant. One way to remove the SO2 is to add limestone, which

*asked on November 15, 2016* -
## Chemistry

A precipitation reaction takes place when a water solution of potassium phosphate, K3PO4, is added to a water solution of cobalt (II) chloride, CoCl2 Write a balanced equation for this reaction

*asked on November 15, 2016* -
## Chemistry

Potassium permanganate, KMnO4, a common oxidizing agent, is made from various ores that contain manganese (IV) oxide, MnO2. The equation shows the net reaction for one process that forms potassium permanganate 2MnO2+2KOH+O2=2KMnO4+H2 Explain why the oxygen

*asked on November 15, 2016* -
## Chemistry

Potassium permanganate, KMnO4, a common oxidizing agent, is made from various ores that contain manganese (IV) oxide, MnO2. The equation shows the net reaction for one process that forms potassium permanganate 2MnO2+2KOH+O2=2KMnO4+H2 What is the maximum

*asked on November 15, 2016* -
## Home economics

List 10 careers in home economics

*asked on September 25, 2016* -
## Chem

Which one of the compond are covalent HF RbF LiF NaF

*asked on September 21, 2016* -
## english

Which type of faulty logic appears in this sentence? Dr. Bishop has never performed a surgery before, so he must not be equipped to be a good surgeon.

*asked on April 25, 2016* -
## Chemistry

Calculate molarity of KNO3 solution if 69 g of salt are dissolved into 250 mL of solution

*asked on March 17, 2016* -
## Science

A spring scaled is used to measure the weight of a object on the earth. The scale on the moon would read what?

*asked on December 6, 2015* -
## Science

A spring scaled is used to measure the weight of a object on the earth. The scale on the moon would read what?

*asked on December 6, 2015* -
## Science

A spring scaled is used to measure the weight of a object on the earth. The scale on the moon would read what?

*asked on December 6, 2015* -
## calculus

what are the inflection points of 5x^2-45/x^2-25

*asked on November 23, 2015* -
## Geometry

Given: BA is congruent to DC; BE is perpendicular to AC; DF is perpendicular to AC. Prove: BE is congruent to DF. The image is of rhombus ABCD. There is a segment connecting A and C with points E and F each about a third of the way into the segment.

*asked on November 10, 2015* -
## Math

A recipe calls for 2/3 cups chocolate but I'm only making a fourth of the batch how much chocolate what I need

*asked on October 8, 2015* -
## living skill

Calculating Voltage across a Resistor (Parallel Circuit and series circuit)

*asked on October 6, 2015* -
## MATH

Use the following time value of money tables to answer the following questions. Assume that the annual rate of interest is 6% for each of the four following problems. i = 6% Time Periods (n) Future Value of 1 Present Value of 1 Future Value of an Annuity

*asked on September 26, 2015* -
## math

find the percentile rank of 4.6 out of these numbers: 1.8, 2.5, 3.9, 4.6, 4.7, 4.8, 4.8, 4.9

*asked on September 23, 2015* -
## physics

A man cleaning his apartment pushes a vacuum cleaner with a force of magnitude 55.8 N. The force makes an angle of 15.3 ◦ with the horizontal floor. The vacuum cleaner is pushed 3.55 m to the right along the floor. Calculate the work done by the 55.8 N

*asked on July 24, 2015* -
## English

Would someone be willing to proof read my English essay? I proof read it but I don't know if I got all the mistakes.

*asked on June 4, 2015* -
## Ap chem

How would the addition of hydrogen gas at constant temperature and volume effect rate=k[h2][I2]?

*asked on April 23, 2015* -
## Chem

What is the order of rate = k[NO]2[Br2]. 2nd order?

*asked on April 23, 2015* -
## Chem

Can someone help with this one? Half life of 55Cr is about 2 hours. A sample of the isotopes delivered from the reactor to lab requires 12 hours. What is the minimum amount of material that should be shipped to get 1.0 mg of 55Cr. I said 32mg but I got it

*asked on April 23, 2015* -
## Chem

What would the unit be if you calculate the rate when A= 0.30 M and b= 0.30 M. I have the calculation done right and its 1.57 x 10 to the -3 but I don't know the unit

*asked on April 23, 2015* -
## Chemistry

Does a k constant have a unit?

*asked on April 23, 2015* -
## Chemistry

At 20 degrees celcius the vapor pressure of toluene is 22 mmhg and that of benzene is 75 mmhg. Assume an ideal solution, equimolar in benzene and toluene. At 20 degrees celcius what is the mole fraction of benzene in the vapor in equilibrium with this

*asked on April 7, 2015* -
## Chemistry

24.0 mL of a 2.4 M silver nitrate is mixed with 32.0 mL of 2.0 M sodium. Calculate the mass of precipitae formed. Calculate the concentration of all ions remaining in solution after the precipitate forms. I don't know how to start this or where to go with

*asked on April 7, 2015* -
## chemistry

16.5 mL of 2.5 M sodium sulfate is mixed with 35.5 mL of 4.5 M sodium nitrate. What is the concentration of all ions in the new solution?

*asked on April 7, 2015* -
## Physics - Electric Field

Find the electric field at a point midway between 2 charges of +40.0e-9 C and +60.0E-9 C separated by a distance of 30.0 cm. My work: q1=40E-9 q2=60e-9

*asked on March 23, 2015* -
## Math 222

I am having difficulties trying to do rational expressions. I have to use the words Domain, Excluded Value, Set, Factor, and Real Numbers to show how I got the answer. Can someone please help me solve this one? g^2-6g-55 ___________ g

*asked on February 19, 2015* -
## Physics

A baseball player slides into third base with an initial speed of 3.8m/s. If the coefficient of kinetic friction between the player and the ground is 0.40, how far does the player slide before coming to rest?

*asked on February 11, 2015* -
## chemistry

An equilibrium is dynamic. true or false

*asked on December 17, 2014* -
## Mechanics, Rigid body

At t = 0 s a flywheel is rotating at 20 rpm. A motor gives it a constant acceleration of 1 rad/s^2 until it reaches 100 rpm. The motor is then disconnected. How many revolutions are completed at t = 21 s? What I've done so far is multiply my 20rpm and

*asked on December 14, 2014* -
## physics

Two canoeists start paddling at the same time and head toward a small island in a lake. Canoeist 1 paddles with a speed of 1.40m/s at an angle of 45 degrees north of east. Canoeist 2 starts on the opposite shore of the lake, a distance of 1.5 km due east

*asked on September 24, 2014* -
## geometry

One endpoint and the midpoint of a segment are given. Find the coordinates of the other endpoint. Show all your work. A. Endpoint: (-1,9) Midpoint: (-9,-10) Endpoint: _______ B. Endpoint: (9,-10) Midpoint: (4,8) Endpoint: ________

*asked on September 11, 2014* -
## Math

What number is 1,000,000 greater than 337,676

*asked on August 26, 2014* -
## History

What did the founding fathers of the United States create in order to ensure that one person did not ever have too much power in the government?

*asked on May 29, 2014* -
## science

if you wanted to consult the geologic time scale for when the first vertebrates evolved, where would you look?

*asked on April 17, 2014* -
## Accounting

During the week ended May 15, 2013, Scott Fairchild worked 40 hours. His regular hourly rate is $31. Assume that his earnings are subject to social security tax at a rate of 6.20 percent and Medicare tax at a rate of 1.45 percent. He also has deductions of

*asked on April 15, 2014* -
## Social Studies

What were the negative impact or effects of the Incas and Aztecs? Thank You

*asked on April 10, 2014* -
## Social Studies

Has the effort of Westerners to aid the rest of the world done more good than harm? Its a opinon but i would like a answer please. Please make your answer at least 6 sentences. Thank you very much

*asked on April 8, 2014* -
## ap biology

What barriers might hinder the acquisition of plasmids?

*asked on April 8, 2014* -
## algebra

. Mrs. Crenshaw has confiscated 4 cell phones from 4 different students because they used them during class. To get the cell phones back, they have to answer the fol- lowing question: What is the probability that no student receives his or her own phone if

*asked on March 10, 2014* -
## Statistics

I have 8 marbles: 3 blue, 1 green, 4v reds. What is the probability of selecting a blue marble twice with replacement and twice without replacement

*asked on March 8, 2014* -
## algebra

There is an 18 inch sandwhich that Jenny cuts and gives half of the sandwhich to Demi and Joel gets 3/4 of what jenny has. Add all up to 18

*asked on March 5, 2014* -
## Math

When Christy made tortillas for the first time, she used all the dough to make 10 tortillas. After making quesadillas, she decided that the tortillas were not large enough. The next time, using the same amount of dough, she made each tortilla the same

*asked on March 5, 2014* -
## Physics

A man at point A directs his rowboat due north toward point B, straight across a river of width 100 m. The river current is due east. The man starts across, rowing steadily at 2.50 m/s and reaches the other side of the river at point C, 150 m downstream

*asked on February 2, 2014* -
## Social Studies

What events in hitler's childhood lead him to become a dictator? Please help and thank you so much.

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

How would you paraphrase this excerpt from "A Tale-Tell Heart" by Edgar Allen Poe; "I bade them search - search well. I led, at length, to his chamber. I showed them his treasures, secure, undisturbed"

*asked on January 12, 2014* -
## Algebra

If f(x)=2x+1 and g(x)=3x-5, find f(g(2)).

*asked on December 4, 2013* -
## math

A support wire runs from the top of a tower to the ground. If the tower is 1200 feet tall and the wire is attached to the ground 500 feet away from the tower, how long is the support wire?

*asked on November 20, 2013* -
## Chemistry

Your space ship has docked at a space station above Mars. The temperature inside the space station is 24oC at a pressure of 745mmHg. A balloon with a volume of 425mL drifts into the airlock where the temperature is -95oC and the pressure is 0.115 atm. What

*asked on November 14, 2013* -
## finance

company starting salary 75,000 retirement benefits 401k with annual contribution of 5% company will match 3% (for max contribution of 8% salary) avg 401k return within mutual fund options at 8% per year sign on bonus 0 annual bonus after 2 years of service

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

5000000 times x divied by y ?

*asked on November 10, 2013* -
## MATH

what is : 4)x+y)-10

*asked on November 10, 2013* -
## math

what is 71 times 45 equal

*asked on November 10, 2013* -
## algebra

Find 2 consecutive integers, the smaller a perfect cube and larger a perfect square.

*asked on November 7, 2013* -
## Calculus

I'm struggling some with the us of trigonomic properties. The problem is integral sin(2x)sec(x) dx and I don't understand how sin(2x)sec(x) simplifies into 2sin(x).

*asked on November 4, 2013* -
## psychics

The lower frequency limit for human hearing is usually considered to be 20.0 Hz. (a) What is the speed of sound in m/s if the air temperature is 20.0ºC? (b) What is the corresponding wavelength for this frequency?

*asked on October 8, 2013* -
## Physics

The lower frequency limit for human hearing is usually considered to be 20.0 Hz. (a) What is the speed of sound in m/s if the air temperature is 20.0ºC? (b) What is the corresponding wavelength for this frequency?

*asked on October 8, 2013* -
## Guidance and discipline

At what age is it typical for a child to begin testing the word no

*asked on September 11, 2013* -
## math

what number could represent the height of a bird 120 feet the surface of the ocean

*asked on August 22, 2013* -
## math

it is claimed that the average age of employees in a large company is 50. a sample of 36 employees is taken and the average age was 49. the standard deviation of the population was 5. use a level of significance of 0.5. what do you think of the claim?

*asked on July 30, 2013* -
## science

you need to prepare 30g of calcium cholride. you have 2m hydrochloric acid and a new container off pure calcium carbonate. Calculate the number of mole of calcium chloride that u need to prepare

*asked on June 29, 2013* -
## math

jimmy is playing a dart game at an arcade. he can earn 2,3,or 6 points with each dart. she scored 24 points. how many ways could he score 24 points given that each dart thrown landed on the dart board?

*asked on May 22, 2013* -
## math

Rohnda is in charge of buying food for the school picnic, she found that hot dogs are in packages of 24, buns in packages of 18, ketchup in boxes of 12, and mustard in boxes of 15. what is the least number of students that can be feed if each student

*asked on May 13, 2013* -
## math

The greatest common factor of 2 numbers is 14, the least common multiple is 168. If the 2 numbers are not 14 and 168, what is the sum?

*asked on May 13, 2013* -
## Math

i need an example problem using log10E=11.4+1.5m when E means radiated energy and m is means magnitude. the log has a base of 10 that's why the 10 is there. please help!!! Again, need an example problem relating it to earthquakes

*asked on April 28, 2013* -
## Math

A bicycle trail is 7miles and 880 yards long.How many total yards is the bicycle trail

*asked on April 9, 2013* -
## CHEMISTRY HELP PLEASE!!

0.350L of 0.160 M NH3 is added 0.140 L of 0.100 M MgCl2 . How many grams of (NH4)2SO4 should be present to prevent precipitation of Mg(OH)2 (aq) ? The Ksp of Mg(OH)2 is 1.8 x 10–11.

*asked on March 2, 2013* -
## physics

At the moment car A is starting from rest and accelerating at 5.0 m/s2, car B passes it moving at a constant speed of 45m/s. How long will it take car A to catch up with car B?

*asked on January 17, 2013* -
## math

There are 5 yellow cards, 4 red cards, and 1 purple card. He draws a card at random, replaces it, and draws a second card. What is the probability that both cards will be red?

*asked on November 25, 2012* -
## Health

Gonorrhea is spread through contact with the ________. A. Anus, !@#$%^&, Mouth, Skin B. !@#$%^&, Anus, Mouth, !@#$%^& C. !@#$%^&, Skin, !@#$%^&, Anus D. Mouth, !@#$%^&, !@#$%^&, Fingers I think it's B?

*asked on October 27, 2012* -
## p.e.

a scull is to rowing as a -------- is to yachting.

*asked on October 25, 2012* -
## Calculus

Assuming that f and g are functions differentiable at a (though we do not know their formulas). Prove that f +g is differentiable at a using the definition of the derivative.

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

A dog running in the +y-direction at 6.0 hears its owner call from behind, and 2.7 later it's running at the same speed in the opposite direction. Calculate the dog's change in velocity. Calculate the average acceleration

*asked on October 12, 2012* -
## Calculus

F(x)=|x-5| evaluate the following limits lim x->5- ( f(x)-f(5))/(x-5) lim x->5+ ( f(x)-f(5))/(x-5)

*asked on October 10, 2012* -
## physics

A wire tooth brace used by orthodontists. The top-most tooth is protruding slightly, and the tension in the wire exerts two forces at 16 º angle on this tooth in order to bring it back into alignment. If the forces have the same magnitude of 19.5 N, what

*asked on September 14, 2012* -
## physics

A 316-kg boat is sailing 12.0° north of east at a speed of 1.60 m/s. 39.0 s later, it is sailing 36.0° north of east at a speed of 4.00 m/s. During this time, three forces act on the boat: a 31.4-N force directed 12.0° north of east (due to an auxiliary

*asked on September 14, 2012* -
## Physics

Two arrows are shot vertically upward. The second arrow is shot after the first one, but while the first is still on its way up. The initial speeds are such that both arrows reach their maximum heights at the same instant, although these heights are

*asked on August 31, 2012* -
## Physics

A rock is dropped from a sea cliff and the sound of it striking the ocean is heard 3.9 s later. If the speed of sound is 340 m/s, how high is the cliff? i know you use the equation y=(initial velocity)(time) + (1/2)(acceleration)(time^2) but I'm having

*asked on July 2, 2012* -
## Science

What happens to approximately 60% of the energy released during the complete oxidation of glucose? A) It is used to synthesize more ATP. B) It is reused to supply the energy for anabolic reactions. C) It is stored in the body as fat. D) It is lost by the

*asked on June 21, 2012* -
## science

In a micelle, why do you find the fatty acid chains of the of the phospholipid molecule are on the inside of the bilayer?

*asked on May 26, 2012* -
## Calculus

How do you use imlicit differentiation to differentiate e^(xy)? I have the problem "use implicit differentiation to find dy/dx. e^(xy)+ x^2 - y^2 = 10. I've gotten to the point whereI have d/dx(e^(xy)) + 2x - 2ydy/dx = 0, but I can't go any further because

*asked on May 22, 2012* -
## Calculus I

Find the derivative of y=ln((1+e^x)/(1-e^x)) I know that the derivative of y=ln(1+e^x) would be (e^x)/(1+e^x), but I'm not sure what to do with the 1-e^x on the bottom here. Can someone help please? Thanks!

*asked on May 21, 2012* -
## Math

Delia works from 8:00 a.m. to 4:30 p.m. and has one hour each day for lunch. How much does she earn for a five-day workweek at $4.80 per hour?

*asked on March 1, 2012* -
## social studies

Were cassette tapes famous when they first came out?

*asked on February 28, 2012* -
## biology

A dominant gene A produces wire-haired texture in dogs. Its recessive aamllele a produced smooth hair. Cross the heterozygous wire-haired dog with homozygous smooth-haired dog. List the genotype and phenotype ratios of all the possible offspring.

*asked on January 21, 2012* -
## physics

A small cart weighs 15.0 N. If a constant force of 25 N is used to move the cart horizontally across the desk, A] What will be the acceleration of the cart? B]How far will the car move in 1.0 second

*asked on December 12, 2011*