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September 20, 2014

Posts by jessica


Total # Posts: 2,606

Calculus
2. Determine the minimum value of the function f(x)= e^(-x) - 2e^x on the interval -1≤x≤2. Answer is minimum value 7.12?
March 6, 2012

Calculus
I have no idea how to do this question. Would be appreciated if someone help =) The velocity of a car is given by v(t)=60(1-[0.7]^t), where v is measured in m/s and t is measured in s. Determine the following: a)What is the acceleration function? b) What is the accerlation at ...
March 6, 2012

Calculus
1.Determine the maximum value of the function f(x)= 5^x -x^5 on the interval 0≤x≤≤2. 2. Determine the minimum value of the function f(x)= e^(-x) - 2e^x on the interval -1≤x≤2.
March 6, 2012

Chemistry
At a given temperature, the elementary reaction A <=> B in the forward direction is first order in A with a rate constant of 2.60 x 10^-2 s^-1. The reverse reaction is first order in B and the rate constant is 8.50 x 10^-2 s^-1. What is the value of the equilibrium ...
March 5, 2012

Calculus
Determine the point on the curve y^2=4x that is closest to the point (1,0) a) (0,0) b) (1,2) c) (0.5,sqrt of 2)
March 5, 2012

Calculus
Determine the absolute extreme values of f(x)=4√x -2x on the interval [1,4] I found the derivative of f(x)=4√x -2x f'(x)=2/x^(1/2) - 2 - I have no idea what to do now.
March 5, 2012

Calculus
Thank you!
March 5, 2012

Calculus
What values of x is there an absolute minimum for the function y= -1/3x^2 + 2x? I found the derivative of the function which is y'=-2/3x + 2 set it to 0=y'=-2/3x + 2 x=3 What do I do now?
March 5, 2012

Calculus
The fuel efficiency, E, in litres per 100 km, for a car driven at speed v, in km/h is E(v)=1600v/(v^2+6400) a)If the speed limit is 50 km/h, determine the legal speed that will maximize the fuel efficiency. Could someone explain to me why the legal speed is 50 km/h to maximize...
March 5, 2012

Calculus
Could someone help me with these questions. If an equation s(t)=t^3 - 2t^2 + 1 describes an object's motion in metres, at what time t, in seconds, will the object be stationary? a) 1s b) 0s and 4/3s c) 0s d) 4/3s -------------------------------------- A box is to be ...
March 4, 2012

Calculus
Could someone help me with these questions. If an equation s(t)=t^3 - 2t^2 + 1 describes an object's motion in metres, at what time t, in seconds, will the object be stationary? a) 1s b) 0s and 4/3s c) 0s d) 4/3s -------------------------------------- A box is to be ...
March 4, 2012

Chemistry
you think you could help me with another? How many moles of chlorine are needed to react with 2.5 moles of sodium?
February 28, 2012

Chemistry
thank you(:
February 28, 2012

Chemistry
6*2=12/1= 12? am i right?
February 28, 2012

Chemistry
How many moles of sodium chloride (salt) can be made from 6 moles of chlorine?
February 28, 2012

chemistry
a gas sample is collected at 16 degrees c and 0.982 atm. if the sample has a mass of 7.40 g and a volume of 3.96 l, find the volume of the gas at stp and the molar mass?
February 28, 2012

algebra 2
solve -x^2+6x-15=0
February 28, 2012

Science
hehehehehehehe
February 27, 2012

Chemistry
a 5.00-g sample of octane is burned in a bomb calorimeter containing 2.00x10^2 h h2o. how much energy, in cal,is released if the water temperature increases 6.00 degrees celcius?
February 27, 2012

algerbra
the length of a rectangle is one foot more than twice its width. If all sides were increased by 7feet the perimeter of the new triangle would be 122 ft. find the new dimensions of the new rectangle
February 23, 2012

Animal Behavior
If someone could give me an example of when developmental homeostasis works in an animal, and when it doesn't. Thanks!!!
February 22, 2012

algebra
One side of a triangle is half the longest side. The third side is 9 meters less than the longest side. The perimeter is 61 meters. Find all three sides.
February 21, 2012

statistics
Using the county auditor's list of households the researcher randomly selected 100 homes and contacted the residents. Of the 100 homes it was found that 62 had cable television. Which of the following are true? The population of interest is the proportion of all homes in ...
February 21, 2012

Physical Science
A 200-L iron tank has a mass of 36 kg. a) Will it float on seawater if empty? b) What mass of potatoes could be added such that the tank would still float? [Note: 1000 L = 1 m3 ]
February 21, 2012

Physical Science
A wooden raft 3 m long x 2 m wide x 20 cm thick floats on a freshwater lake. A) Determine the buoyant force? B) If the raft itself has a mass of 600 kg, how many 65-kg people could it support?
February 21, 2012

physics
A wire having mass per unit length of 0.440 g/cm carries a 2.80 A current horizontally to the south. What are the direction and magnitude of the minimum magnetic field needed to lift this wire vertically upward?
February 21, 2012

algebra
the price of a car depricates over time at a rate of approximately 18% according to the formula (C)t=36,500(0.82)^t. what was the inital cost of the car? what will the car be worth in 4 years? when will the car be worth less than 5,000?
February 21, 2012

Physics
A penny is placed at the outer edge of a disk (radius = 0.159 m) that rotates about an axis perpendicular to the plane of the disk at its center. The period of the rotation is 1.50 s. Find the minimum coefficient of friction necessary to allow the penny to rotate along with ...
February 20, 2012

Physics
A penny is placed at the outer edge of a disk (radius = 0.159 m) that rotates about an axis perpendicular to the plane of the disk at its center. The period of the rotation is 1.50 s. Find the minimum coefficient of friction necessary to allow the penny to rotate along with ...
February 20, 2012

physics
A 32.2-kg child swings on a rope with a length of 6.06 m that is hanging from a tree. At the bottom of the swing, the child is moving at a speed of 4.2 m/s. What is the tension in the rope?
February 18, 2012

Physical Science
Where did you get the 19.6 from? Also what formula are you using? The Vf^2 = Vo^2 + 2g*d....i've never seen that before
February 17, 2012

Physical Science
​ A 3-kg stone is dropped from a height of 100 m.  Find its kinetic and potential energies when it is 50 m from the ground.  
February 17, 2012

SCIENCE
I have a homework pqage for kindergarten that says Petal Patterns. Label each pattern. I'm not sure what the teacher is looking for. Can anyone help me?
February 16, 2012

science
what is the conclusion for what types of water will make a carrot softer
February 15, 2012

biology
1) I can't finish my homework due to this one question, please tell me where I can find this question, thanks! What are levels of protein structure of Angiosperms?
February 14, 2012

physics
A car drives off a sheer cliff, moving horizontally at 17.2 m/s. If the base of the cliff is 14.4 meters below, estimate how long does the car remains in the air.
February 13, 2012

physics
A car drives off a sheer cliff, moving horizontally at 17.2 m/s. If the base of the cliff is 14.4 meters below, estimate how long does the car remains in the air.
February 13, 2012

chemistry
how many grams are contained in 500.g of a 25% solution of H2SO4?
February 13, 2012

physics
A golf ball is struck with a five iron on level ground. It lands 92.7 m away 4.40 s later. What was (a) the direction and (b) the magnitude of the initial velocity?
February 12, 2012

Literature
theseus talking about plays
February 10, 2012

chemistry
Calculate the molarity of 2.05 L of a solution containing 1.51 g of dissolved KBr
February 9, 2012

chemistry
What is the molarity of an aqueous solution containing 43.7 g of glucose (C6H12O6) in 1.1 L of solution?
February 9, 2012

Algebra
Rachel and Lindsay are in third place in a race. Due to a time penalty, they must start the next leg 90 minutes after the second place team. If rachel and lindsay travel at an average rate of 16.8 mph and the second place team travels at an average rate of 14 mph, how long ...
February 8, 2012

Science
I learned the formula to be v=gt...why are you subtracting? Also what is vf and vi?
February 7, 2012

Science
a ball is thrown upward at a speed of 12 m/s. It will reach the top of its path in about: a) 0.6 sec b) 1.2 sec c) 1.8 sec d) 2.4 sec Please explain how you find the answer!!! I cannot figure it out
February 7, 2012

pre calculus
The graph of a one-to-one function is shown below. Draw the graph of the inverse function, f^(-1) , and submit it to the Dropbox. Please show your work
February 5, 2012

physics
A 200g mass attached to a horizontal spring oscillates at a frequency of 2.0 Hz. At one instant, the mass is at x= 5.0cm and has v= -30cm/s. find amplitude
February 3, 2012

chemistry
How can I group white substances into 2 groups according to their properties&list the properties of each group? Calcium carbonate, citric acid, sucrose, Phenyl salicylate, Potassium iodide,and Sodium chloride Also, which of them dissolves in water and which has solubility in ...
February 2, 2012

chemistry
How can I group white substances into 2 groups according to their properties&list the properties of each group? Calcium carbonate, citric acid, sucrose, Phenyl salicylate, Potassium iodide,and Sodium chloride Also, which of them dissolves in water and which has solubility in ...
February 2, 2012

trig
use the discriminant to solve for the smallest value of b that would make the roots of the equation x^2+bx+5=o imaginary
February 2, 2012

trig
a grocery store display consists of cases of soda. there are 15 cases at the base, and 1 case at the top. if there are 15 rows, how many cases are needed for the entire display? a) 180 b)30 c)130 d)15
February 1, 2012

alg2/trig
how much money would you earn in the fifth year? would you just plug in 5 into n to get your answer?
February 1, 2012

Physical Science
The string of a certain yo-yo is 80 cm long and will break when the force on it is 10 N. What is the highest speed the 200 g yo-yo can have when it is being whirled in a circle? Ignore the gravitational pull of the earth on the yo-yo.
February 1, 2012

Physical Science
So far for: A) w=mg =(70 kg)(25m/s^2) = 1750 N B) m=wg =(1750 N)(9.8 m/s^2) =1666 (I don't know what the units would be for this or if it even right) If you can help, it would be greatly appreciated!
February 1, 2012

Physical Science
Thank you!
February 1, 2012

Physical Science
A bicycle and its rider together have a mass of 80 kg. If the bicycle's speed is 6m/s, how much force is needed to bring it to a stop in 4 seconds
February 1, 2012

Ochem
What volume of 6.43% (wt.vol.) NaOCl solution is required to oxidize 221 mg of 9-fluorenol to 9-fluorenone? I'm not to sure of where to start with this problem. Please help!
February 1, 2012

math
a grocery store display consists of cases of soda. there are 15 cases at the base, & 1case at the top. if there are 15 rows, how many cases are needed for the entire display? a) 180 b)30 c) 130 d) 15
January 31, 2012

Math
The product of two consecutive odd intergers is 143. Find the intergers.
January 31, 2012

alg2\trig
a colony of 300 bacteria doubles each day. write an explicit formula to determine how many bacteria there would be on the nth day. how would you do this?
January 31, 2012

Finance
I am working on an assignment in which I need to put together a pro forma balance sheet. At the end of the assignment, I need to find the predicted values of accounts for the upcoming year. In 2011, Notes Payable was 11.28 million; Long Term Bonds were 7 million; Common Stock ...
January 30, 2012

Physical Science
Thank you so much!
January 29, 2012

Physical Science
A person dives off the edge of a cliff 33m above the surface of the sea below. Assuming that air resistance is negligible, (a) How long does it dive last? (b) and with what speed does the person enter the water?
January 29, 2012

Math
The perimeter of a geometric figure is the sum of the lengths of its sides. If the perimeter of a pentagon is 48 meters, find the length of each side.
January 28, 2012

Chemistry
A quantity of ice at 0.0°C was added to 25.0 g of water at 21.0°C to give water at 0.0°C. How much ice was added? The heat of fusion of water is 6.01 kJ/mol and the specific heat is 4.18 J/(g · °C). _g
January 28, 2012

math
in 1991 the life expectancy of males was 65.4 in 1998 it was 68.8 let e represent life expectancy in year t and let t represent number of years since 1991
January 26, 2012

English
Please tell me where I can find Articles about Energy Resource and issues. Thanks!
January 24, 2012

world history
the answer is ukiyo-e
January 24, 2012

chemistry
calculate the energy required to heat 1.00L of ice at -50.0C to steam at 180.0C
January 17, 2012

Math
What is the y-intercept of 4x+8y=12?
January 17, 2012

Mathematics
A farmer keeps hens and rabbits on his farm. One day, he counted a total of 70 heads and 196 legs. How many more hens than rabbit does he have? Explain your working please. Your help is greatly appreciated.
January 15, 2012

math
Sandy decided to give one-fourth of her CDs to Jenn. Then she gives one-half of the remaining CDs to Bob. If she is left with 6 CDs,how many CDs did she have to begin with?
January 3, 2012

Math
A wall hanging is x inches wide and has a height of 4x inches. If the perimeter is 40inches, what is the height in inches? Please help!
December 31, 2011

Pre-Cal
Find the area of each circular segment to the nearest tenth, given its central angle, x, and the radius of the circle. x= pi/8, r=7
December 28, 2011

math
the shorter leg of a 30-60-90 triangle is 9.4 inches long. find the perimeter.
December 19, 2011

Math
Haha, Steve is correct, I apologize for the guesswork. :/ It's g(x)= 1/3 -4/3x. Going off the work Reiny did, I am still rather clueless, so considering it's only two problems, I guess I'll just have to do some guesswork myself. Thank you for the help, though!
December 19, 2011

Math
I am not exactly sure of what I'm supposed to do in the following question: Describe and correct the error, given the functions f(x)=3x - 5 and g(x)=1/3 - 4/3. The first equation is as follows: g(-3)= 1/3 - 4/3 (3) =1/3 - 4 = -3 2/3 The second equation is: f(1)= 1/3 - 4/3(...
December 19, 2011

chemistry
A sample of cesium metal reacted completely with water, evolving 47.0 mL of dry H2 at 31°C and 769 mmHg. What is the equation for the reaction?
December 13, 2011

physics
A student investigates skateboarding down a slope. She times how long it takes her to skateboard between two lines on a sloping pavement. She varies the distance between the two lines and records her results in a table. Distance s/m time t/s Distance 2 Time 2.32 Distance 4 ...
December 11, 2011

physics
A student investigates skateboarding down a slope. She times how long it takes her to skateboard between two lines on a sloping pavement. She varies the distance between the two lines and records her results in a table. Distance s/m time t/s 2 2.32 4 4.23 9 8.22 11 9.53 The ...
December 11, 2011

philosophy
can anyone tell me is there any strong response aganist norcoss argument that if it wrong to kill puppies, so it is also wrong to support farming factory
December 8, 2011

philosophy
WHat is the strongest response against norcoss argument on puppies, pig and people
December 8, 2011

Physics 201
Suppose the mass of the wing is 0.258g and the effective spring constant of the tissue is 4.00E-4 N/m. Distance d1 = 3.03 mm and distance d2 = 1.76 cm. If the mass m moves up and down a distance of 2.08 mm from its position of equilibrium, what is the maximum speed of the ...
December 5, 2011

english
Am doing Autism and I have to give farther information. Thanks The cognitive part: I have...(1) Selecting attention, I have they absorve things..(2) Concrete processing, i dont have anything for this one. (3) Rote memory: I putted recalling.
December 4, 2011

english
How can you have Motivation, Forecast and Orientation in speech intorduction? like show the audience pictures etc?..thanks!
December 4, 2011

physics
a rod supports a 2.35 kg lamp. a)what is the magnitude of the tension in the rod? b)calculate the components of the force that the bracket exerts on the rod.
December 4, 2011

English
Am doing a project about Autism, what are the Cogngntive and pscohosocial of Autism and where can I find them? Thanks!
December 3, 2011

grammer
what is the adverb and verb for the sentence The players spent all day there.
December 1, 2011

math
The gcf(a,b)=495 and cm(a,b)=31,185 Find possible values of a and b if a is divisible by 35 and b is divisible by 81
November 29, 2011

V/CV OR VC/V PATTERN
v/vc
November 29, 2011

Chemistry
Oops, sorry I meant .004 under initial moles of RNH2 not .001. Regardless I get an answer of 9.84 instead of 10.81
November 26, 2011

Chemistry
For part b of problem 2, I used ..RNH2 + HCl--> RNH3 + Cl I.+.001..+.002...0......0 C.-x......-x.....+x....+x E+.001-x..+.002-x..+x...+x Is this correct? My issue with these problems is that I don't know when to use the variables (like +x and -x for the C in ICE) or ...
November 26, 2011

Chemistry
Regarding your first post, I believe I used aspirin as the weak acid. In a previous problem which was related to these problems, it stated "aspirin is a weak acid with a Ka of 3.0x10^-5"
November 26, 2011

Chemistry
Sorry, one more question. For .........RNH2 + HCl ==> RNH3^+ + Cl^- initial...0....................... added...........0 added..........2.0 added..........4.0 etc change..................... the initial RNH2 is 0? Shouldn't it be the initial moles in the problem (....
November 26, 2011

Chemistry
For problem 1, if it were changed to 20 mL of the .07222M aspirin solution and 5mL of .2M NaOH, how would solving it differ? I tried ...........HA + NaOH ==> NaA + H2O initial..0014444.................. add..............001............ change...-.001.-.001.....+.001...+.001...
November 26, 2011

Chemistry
1.Calculate the pH of a solution prepared by mixing 20mL of the .07222M aspirin solution with 10mL of .2M NaOH. 2. Calculate the pH for the titration of 40mL of .1M solution of C2H5NH2 with .1M HCl for a)0 mL added and b)20 mL added c)40 mL added d)50mL added. Kb= 6.4x10^-4
November 26, 2011

Chemistry
For the ICE box, you are supposed to use the molarity of the aspirin. I did not realize that. Thank you so much for your help!
November 26, 2011

Chemistry
The answer that was in my answer key was 2.83 but I got 3.48. Is there something wrong in the calculations?
November 26, 2011

Chemistry
Aspirin is a weak acid with a Ka of 3.0x10^-5. Find the pH of a solution by dissolving .65g of aspirin in water and diluting it to 50mL. You can use RCOOH to represent aspirin. Molecular weight of aspirin is 180g/mol
November 26, 2011

e-business
In about 100 words, explain what kinds of features of characteristics a midsize business would seek in its electronic commerce software that would not matter to a smaller business.
November 25, 2011

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