Wednesday
December 7, 2016

# Posts by Jessica

Total # Posts: 3,227

Chemistry
Calculate the concentrations of each of the ions in 0.25 M Fe(NO3)2. a) [Fe2+], M b) [NO3-], M
June 27, 2011

science
Which of the following best describes plasma? A) a group of super cooled particles with very low kinetic energy B) an ionized group of particles with low kinetic energy C) a gas that becomes a solid without first becoming a liquid D)an electrically charged gas with very high ...
June 23, 2011

statistics
Build a 95% confidence interval for the mean of the population from the given sample data. Assume that the population has a normal distribution. 16.4, 15.7, 16.2, 15.8 17.1 15.8, 15.9, 16.0, 16.4 15.0
June 22, 2011

statistics
Use the margin of error E = \$10, confidence level of 99%, and ó = \$40 to find the minimum sample size needed to estimate an unknown population mean, .ì
June 22, 2011

statistics
The weights of certain machine components are normally distributed with a mean of 9.75g and a standard deviation of 0.08g. Find the weights that separate the top 5% and the bottom 5%.
June 22, 2011

statistics
A bank’s loan officer rates applicants for credit. The ratings are normally distributed with a mean of 175 and a standard deviation of 15. If an applicant is randomly selected, find the probability of a rating that is between 150 and 200.
June 22, 2011

statistics
A final exam in Math 157 is normally distributed and has a mean of 75 with a standard deviation of 12. If 36 students are randomly selected, find the probability that the mean of their test scores is greater than 70.
June 22, 2011

chemistry
Discuss in detail, one way in which atomic nuclear decay takes place. What is the significance of atomic nuclear decay? Analyze the societal implications of using this process.
June 18, 2011

math
The graph of f (x)₌√x undergoes a vertical stretch by a factor of k, k›1.The vertically stretched graph would look the same if it had been horizontally compressed by a certain factor. Determine this factor
June 18, 2011

chemistry
How much heat flows from 20kg of 90 degrees water placed in contact with 20kg of 10 degrees water, producing a final temperature of 50 degrees? c=4186j/kgC
June 16, 2011

Algebra
A can of soda is placed inside a cooler. As the soda cools, its temperature T(x) in degrees Celsius is given by the following exponential function, where is the number of minutes since the can was placed in the cooler. T(x)=-22+44e^-0.03x Find the initial temperature of the ...
June 15, 2011

chemistry
Can you please explain the buffer system used in buffered aspirin? For example, what is the chemical formula of the buffer that is used? How does it react with the aspirin?
June 14, 2011

statistics
researchers believe a new sleep on average 10 hours per night ( µ = 10), with a population standard deviation of 2.3 hours(s=2.3) it is assume that the number of hours of sleep per night is normal distributed , however you think this drug causes people to sleep less than...
June 13, 2011

chemistry
How could you separate lauric acid from a-naphthol?
June 12, 2011

Algebra
Find the average rate of change of f(x) 3x^2-4x from x=3 to x=6 . Simplify your answer as much as possible.
June 9, 2011

College Algebra
Write the following as an radical expression. v^(4/5)
June 8, 2011

chemistry
if 10 ml of a 2M standard solution is used to neutralize 20mL of an unknown base what is the molarity of the unknown and is this standard solution an acid or base?
June 7, 2011

Math
Can (4x^3)y - 9xy^3 factor?
June 7, 2011

geometry
whats the volume of a sphere with diameter 30ft with the answer in the terms of pie?
June 6, 2011

social studies
A study of the causes of the American Revolution of 1776, the French Revolution of 1789, and the Russian Revolution of 1917 best supports the generalization that revolution is most likely to occur when
June 6, 2011

History
One of the most effective forms of resistance that slaves employed against their masters was A. earning money to buy their freedom. B. not having children. C. working slowly. D. open rebellion. I believe it's C, my book doesn't explain it in great detail so i'm ...
June 5, 2011

Chemistry
Thank you DR Bob
June 1, 2011

Chemistry
Hello Dr Bob,, I am still a little confused is this what it will look like 13.5/2.70=5 then take 5*5*5=125
June 1, 2011

Chemistry
The density of aluminum is 2.70g/cm3. If a cube of aluminum weighs 13.5 grams whatis the length of the edge of the cube. I need help with the formula to figure this one out.
June 1, 2011

Math
Find the surface area of a right octagonal pyramid with height 2.5 yards, and its base has apothem length 1.5 yards.
June 1, 2011

geometry
equation x+3y+2z=6 (6,2,3) how would you sketch the plane on a set of axes? is it supposed to look like a triangle? becuse my paper says it makes a trangular pyramid. i don't get it
May 31, 2011

statistics
A professional gambler claims that he has loaded a die so that the outcomes of 1,2,3,4,5,6 have corrresponding probabilities of 0.1, 0.2, 0.3, 0.4, 0.5, and 0.6. Can he actually do what he has claimed? Is a probablility distrubion described by listening the outcomes along with...
May 29, 2011

eth 125 week7
Part I Complete the chart following review of relevant information provided in Chapters 9 and 10 of our reading material. The first three groups are identified for you. Select a fourth group considered as Hispanic/Latino from the readings in order to complete the assignment. ...
May 28, 2011

Math
So the question is basically asking which mountains peaks can be seen from Oahu. Island Distance(Mi) Mountain Height(ft) Lanai - 65 - Lanaihale - 3,370 Maui - 110 - Haleakala - 10,023 Hawaii - 190 - Mauna Kea - 13,796 Molokai - 40 - Kamakou - 4,961 A) Radius of earth= 3960 mi...
May 25, 2011

Chemistry
Calculate how much heat 32.0 g of water absorbs when it is heated from 26.0°C to 73.5°C.
May 25, 2011

history
Describe the treatment of US citizens of japanese descent during wwII.
May 24, 2011

history
describe the treatment of us citizens of japanese descent during world war II.
May 23, 2011

Math
How do you solve 7x - (-6 - 2x) - x
May 23, 2011

Chemistry - DrBob PLEASE
A glass of ice water was made by adding six 25 g ice cubes to one liter of water. If the water was initially 25C and the ice cubes were initially at -15C, what is the final temperature of the ice water? (I don't know how to get it.)
May 23, 2011

Chemistry
A glass of ice water was made by adding six 25 g ice cubes to one liter of water. If the water was initially 25C and the ice cubes were initially at -15C, what is the final temperature of the ice water?
May 23, 2011

fundaents
bobpursley, you need to read up on Mazlow's hierarchy of needs. Children's basic physiological needs must be met before they can focus on fulfilling the need to learn and grow.
May 22, 2011

POETRY, PART 1
From what I have gathered in my Penn F literature book it is B. Both connotative and denotative.
May 20, 2011

statistics
The following linear equation ,y= b0 = b1x, is a regression line with y-intercept b0 and slope b1.
May 19, 2011

statistics
The value of the correlation coeficient can be between 0 and 1.
May 19, 2011

social studies
Who had the smoothest transition from communism
May 18, 2011

Chemisty
What is the Net Ionic Equation for the following: a.) NH4Br, NaOH b.) Li2CO3, HClO4 c.)Pb(NO3)2, Kl
May 18, 2011

Math
Divide. Express your answer in simplest form. 1 3/5 , 1/4
May 17, 2011

Statistics
is this true or false? The linear correlation coefficient, r, is a numerical measure of the strength of the relationship between two variables representing quantitative data.
May 17, 2011

math 117
A launched rocket has an altitude in meters, given by the polynomial h+vt-4.9^2, h is the height in meters v is the velocity in meters per second and t is the number of seconds for which it takes the rocket to become airborne. If the rocket is launched from the top of a tower ...
May 15, 2011

mitosis and meiosis
what does mitosis mean?
May 15, 2011

government
The facts of a case a. are largely irrelevant, in that the judiciary has wide freedom with decisions. b. affect which law or laws will apply to the case. c. are important only if the case involves a statutory dispute. d. are important only if the case involves a constitutional...
May 13, 2011

geometry
What is the measure of angle DBC if the measure of angle ABD is represented by 4x, the measure of angle DBC is represented by 3x and the measure of angle ABC is 77 degrees?
May 11, 2011

math
use technology to find the P-value for a two tailed test with n=28 and a test statistic t=2.032 P-value =???? Help please! i don't understand this
May 8, 2011

Physics
If the change in position Dx is related to velocity v (with units of m/s) in the equation Dx = Av, the constant A has which dimension? a) m/s2 b) m c) s d) m2 I'm not sure how to eliminate the seconds from the velocity. Thanks in advance for any help!
May 5, 2011

conseptual physics
if you hold one end of a metal nail against a piece of ice, the end in your hand soon becomes cold. does cold flow from the ice to your and? why?
May 3, 2011

math
input/x,-2,0,2 rule/-x+3 output/y
May 3, 2011

Integrated Physics and Chemistry
Energy that is dissipated during heat flow cannot usually be used to produce work. True False
May 3, 2011

Chemistry
H2 + F2--> 2HF deltaH = 518.0 kJ H2 ----> 2H deltaH = 436.8 kJ F2 ---> 2F deltaH = 158.2 kJ (a) calculate Delta H for H + F---> HF (b) what is the standard enthalpy change of formation of F2 Help please!!! i think this is easier than i'm making it. for (b) ...
April 28, 2011

science
If the temperature at sea level were 23C,what would the air temperature be at a height of 2 kilometers under average conditions?
April 26, 2011

math
crime wave HAHAHAHAHAHAHAHAHA it is soooooooooo... funny---for those of u who didn't get that ---that was a joke HAHAHAHAHAHAHAHA i am so halariously smexy
April 25, 2011

Chemistry
A nitric acid solution is found to have a pH of 2.70. Determine [H3O+],[OH-], and the number of moles of HNO3 required to make 5.50L of the solution.
April 24, 2011

what happens when you watch tv to much?
April 24, 2011

Med Term
help me by writing it
April 22, 2011

Science
i need help with this experimental design.the topic is...what happens to your image that is initially observed in a flat mirror from 10 feet away and then you move further away to 20 feet? But i need to know how do I make up procedures (steps-in outline form) for this ...
April 22, 2011

Science
What happens to your image that is initially observed in a flat mirror from 10 feet away and then you move further away to 20 feet?
April 19, 2011

Math
A plumber charges \$45 for a service call, plus \$70/h for her time. a. Find the cost of a two hour service call. b. How long was a services call that cost \$150? Also ....... as the weight held by a spring increases, the length of the spring increase proportionally. suppose a 2-...
April 19, 2011

science
students can use any of the items above to build an electromagent. which item is NOT needed to build an electromagent?
April 18, 2011

geometry
In the diagram below of isosceles trapezoid DEFG, DE ll GF. DE = 4x − 2, EF = 3x + 2, FG = 5x − 3, and GD = 2x + 5. Find the value of x. the answer is 3 but idk how, please help
April 18, 2011

chemistry finding moles
I know the formulas to a mole which equals 6.02x10 to the 23rd power but i have no idea what to do with the formula when converting grams to moles visa versa or atoms or molecules, and i have no idea what goes with what as far as what resources you're supposed to use. Some...
April 14, 2011

chemistry
True or False? Two identical beakers of water that have been over the same size flame for the same length of time will ALWAYS stay at the same temperature, no matter how much water is inside.
April 14, 2011

Chemistry
Determine the prcentage composition of the compund HCl?
April 13, 2011

math
Can some one help me in this math problem please?? This is the problem I need help with .. 10x-6(x+2)=36
April 13, 2011

Math
A car travels along a straight road, heading east for 1 h, then traveling for 30 min on another road that leads northeast. If the car has maintained a constant speed of 48 mi/h, how far is it from its starting position? Round your answer to 2 decimal places.
April 13, 2011

Math
A parallelogram ABCD has lengths of sides and angles given below. Find the length of the diagonals AC and BD. (Round your answers to two decimal places.) AB = DC = 6 and AD = BC = 3, A = 40°
April 13, 2011

math
what is the excluded values for the fraction a --- 3-2a
April 12, 2011

algebra 2
how do u solve 3m-n=2m+n, for m
April 12, 2011

CALC
An open box is to be constructed so that the length of the base is 4 times larger than the width of the base. If the cost to construct the base is 5 dollars per square foot and the cost to construct the four sides is 3 dollars per square foot, determine the dimensions for a ...
April 8, 2011

Algebra 1
1/9=3/y do cross multiplication and then divide to find y.
April 5, 2011

graphs of sin
Is it 2pi/3????
April 5, 2011

graphs of sin
find an equation of the form y = c+a sin(bx) with the max of 2,min of -2, and period of 3. So far i've got 2sin___ . I don't know how to find the period.
April 5, 2011

where did you get the 2Plrad?
April 5, 2011

The angular speed of a large pulley wheel that has a radius of 15, is 50 revolutions/min. Find the angular speed and the rim speed of the smaller wheel that has a radius of 5. The rim speed is going to be the same. I got the angular speed but I can't figure out why the rim...
April 5, 2011

Chemistry
you measure 5.3g of KOH and dissolve it in enough water to make 400 ml of solution. what is the molarity of this base? You want to neutralize this base with a 3.7M H2SO4. How much sulfuric acid is necessary to do this? x=5.3g/39+16+1 = 5.3/56=.095m M=moles/L of solution = .095...
April 5, 2011

chemistry
ok i don't really understand the answer to this question.
April 5, 2011

chemistry
the temperature of water in a 100 mL container was raised from 26.7 degrees C to 62.3 degrees C. how much heat in calories was added
April 5, 2011

Early Childhood Education
1.c 2.a 3. b
April 2, 2011

chemistry
what is the specific heat capacity of substance X when 34.80 g of X is heated from a starting temperature of 20.5 C to 40.9 C by 2.54 kJ of energy
March 31, 2011

Physics
A submarine has run into trouble and is stuck at the bottom of the ocean. Several people are on board and must make their way to the surface without any diving gear. The air pressure aboard the submarine is 3.100 atm. The air temperature inside the submarine is 10.01 ¢XC ...
March 29, 2011

chemistry
Using the activity series, write a balanced chemical equation for the following reactions: 1. iron metal is added to a solution of copper (II) nitrate 2. zinc metal is added to a solution of magnesium sulfate 3. hydrobromic acid is added to tin metal 4. hydrogen gas is bubbled...
March 27, 2011

Applications
Determine the median of the following numbers25,28,22,27,25,20/30,23,27, and 29
March 23, 2011

physics
A car is driven 110 km west and then 25 km southwest. What is the displacement of the car from the point of origin (magnitude and direction)? ...km ... degrees south of west
March 20, 2011

english
im studying for test and I am supposed to write about "what are gender roles, how do they effect,, influence, inform our conceptions of masculinity and feiminity. I especially don't get the femininty and masculinity part. Thanks and I appreciate ur help!
March 19, 2011

chemistry
find the concentration of HCL if the pH of the solution is 0.50
March 17, 2011

chemistry
4.72 moles of sulfur trioxide molecules contain how many oxygen atoms? i know the answer is 8.53 x 10^24 but i do know how my professor got it **this is one of my practice exam question!
March 14, 2011

Physics
If you have two tables and in Table 1, is using the indirect method and you have the measurements, 11.37 and 12.57 cm. In Table 2, is using the direct method which has the measurement of one item out of 100 with the measurements of 0.642, 0.741, and 0.683 cm. What is the ...
March 14, 2011

pre algebra
Multiple the first equation by -1: -y=-x+2 Add it from the second one to get: y=4x+1 +(-y=x+2)= 0=3x+3 Subtract 3 from both sides: -3=3x Divide by 3 x=-1 Plug it in for one equation: y=(-1)-2 y=-3
March 14, 2011

chemistry
1652 x (3.82 moles/4 moles) = 1577.66
March 13, 2011

Science - Physical
Earth's magnetic field induces some degree of magnetism in most of the iron objects around you. With a compass you can see that cans of food on you pantry shelf have north and south poles. When you pass the compass from their bottoms to their tops, you can easily identify ...
March 13, 2011

Accounting
American Food Services, Inc., leased a packaging machine from Barton and Barton Corporation. Barton and Barton completed construction of the machine on January 1, 2011. The lease agreement for the \$4 million (fair value and present value of the lease payments) machine ...
March 10, 2011

Accounting
On June 30, 2011, Georgia-Atlantic, Inc., leased a warehouse facility from IC Leasing Corporation. The lease agreement calls for Georgia-Atlantic to make semiannual lease payments of \$585,423 over a three-year lease term, payable each June 30 and December 31, with the first ...
March 10, 2011

Math/Algebra