Posts by Marissa
Total # Posts: 325

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. 
History
I think B. 
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 The spread of ... 
math
Never mind. I forgot about multiplying it by 4 because it's supposed to be the velocity for 4 seconds. 
math
So divide both sides by t and end up with v=32? That doesn't seem right. 
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? 
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 
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 optimization function (for any... 
Chemistry
How many moles of hydrogen from when 10 moles of methane react completely? 
Chemistry
How many moles of water vapor react to yield 546.234 moles of hydrogen? 
Chemistry
Write a conversion factor that could be used to convert between moles of methane and moles of hydrogen 
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 keep track who's ... 
Chemistry
Sorry were working in a group and not everyone has the same questions and so we know who's question is which sorry for the confusion ! 
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 contains calcium carbonate, ... 
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 
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 gas is in excess 
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 mass, in kilograms, of ... 
Chemistry
That was part A this is part B the actual question is different 
Home economics
List 10 careers in home economics 
Chem
Which one of the compond are covalent HF RbF LiF NaF 
Statistics
Confidence interval for one proportion 
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. 
Chemistry
Calculate molarity of KNO3 solution if 69 g of salt are dissolved into 250 mL of solution 
Science
A spring scaled is used to measure the weight of a object on the earth. The scale on the moon would read what? 
Science
A spring scaled is used to measure the weight of a object on the earth. The scale on the moon would read what? 
Science
A spring scaled is used to measure the weight of a object on the earth. The scale on the moon would read what? 
calculus
what are the inflection points of 5x^245/x^225 
Math
10 is the correct answer 
Math
12 is the correct answer 
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. 
Math
So would she have 26 slices? 
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 
living skill
Calculating Voltage across a Resistor (Parallel Circuit and series circuit) 
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 Present Value of an ... 
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 
grammar
Harriet couldn’t study for her comma quiz because she was asked to open the door for the neighbor, whom the dog wouldn’t leave alone in the backyard. 
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 force. Answer in ... 
nutrition
D) Secretes hormones that regulate how much we eat. 
English
Do you know of any sites that will proof read it I have read it a couple of times but I want to make sure I get it right 
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. 
Ap chem
How would the addition of hydrogen gas at constant temperature and volume effect rate=k[h2][I2]? 
Chem
What is the order of rate = k[NO]2[Br2]. 2nd order? 
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 wrong and I don't... 
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 
Chemistry
Does a k constant have a unit? 
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 solution? If you use pv=... 
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 it... 
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? 
english
Jk 
english
Thanks guys you failed me 
Physics  Electric Field
Pressed enter too soon. My work continued: r=.30 m Forceelectric = 8.99e9 * ((40e9*60e9)/(.3*.3) = 2.397 
Physics  Electric Field
Find the electric field at a point midway between 2 charges of +40.0e9 C and +60.0E9 C separated by a distance of 30.0 cm. My work: q1=40E9 q2=60e9 
Chemistry
Here's the work: a) .575 g Li3N(1 mol Li3N/34.83 g Li3N)(6 mol Li/2 mol Li3N)(6.941 g L/1 mol Li) = 0.334 g Li Plug in the molar ratios and masses of N2 for part B. 
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^26g55 ___________ g 
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? 
chemistry
An equilibrium is dynamic. true or false 
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 100rpm by (2pi/60) to... 
6TH GRADE
= Ratios to 8/10 
Science
I see the answer but I am tring to fight out the practice 
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 of canoeist 1. A) In ... 
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: ________ 
Math
What number is 1,000,000 greater than 337,676 
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? 
science
if you wanted to consult the geologic time scale for when the first vertebrates evolved, where would you look? 
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 $48 for federal ... 
Help Here
Help me please. 
Social Studies
On the world or in general. I'm trying to argue the mayan civilization was the best and i need to know what negative effects did the Incas and Aztecs do. 
Social Studies
What were the negative impact or effects of the Incas and Aztecs? Thank You 
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 
math
the odds are against 2/7. Meaning 2 out of 7 chances you are going to have s. And 5 out of 7 you will not get S. 
ap biology
What barriers might hinder the acquisition of plasmids? 
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 Mrs. Crenshaw hands ... 
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 
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 
Math
Thank you PsyDAG this will be very helpful. 
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 thickness but 25% larger... 
STATISTICS
a student took all 8 test in a semester and had an average of 84. then the teacher dropped the lowest test score which was a 63. what was the new test average after that? 
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 from his starting point... 
Social Studies
What events in hitler's childhood lead him to become a dictator? Please help and thank you so much. 
English
How would you paraphrase this excerpt from "A TaleTell 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" 
Algebra
Thank you very much!!! 
Algebra
If f(x)=2x+1 and g(x)=3x5, find f(g(2)). 
math
Thank you! 
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? 
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 is the new volume of... 
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 annual bonus of $... 
MATH
5000000 times x divied by y ? 
MATH
what is : 4)x+y)10 
math
what is 71 times 45 equal 
algebra
Thank you Ms.Sue!!!! 
algebra
Find 2 consecutive integers, the smaller a perfect cube and larger a perfect square. 
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). 
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? 
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? 
Guidance and discipline
At what age is it typical for a child to begin testing the word no 
Math
It's 20 
math
12*120=1440 
math
what number could represent the height of a bird 120 feet the surface of the ocean 
Science
what is the central theme of the first green revolution? 
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?