# Posts by emily

Total # Posts: 3,005

chemistry
The decomposition of potassium chlorate, KClO3, gives oxygen gas and solid potassium chloride. How many grams of KClO3 are needed to produce 5.00 L of Oxygen gas at STP? Suppose that the reaction described above produces 4.80 L of O2 in the laboratory. What is the percent yield?

Physics
in an impulse/ change in momentum problem where mv(final)-mv(initial)=Ft if the initial velocity is zero can i cancel out the masses?

Chemistry
how many joules of heat are given off when 5.0 grams of water cool from 75 degrees celsius to 25 degrees celsius? ( specific heat of water = 4.18 jg degrees celsius)

Math
write the particular equation of a quartic function that could, according to Descartes Rule of Signs have four positive zeros.

physics
You are trying to raise a bicycle wheel of mass m and radius R up over a curb of height h. To do this you apply a horizontal force F. What is the smallest magnitude of the force F that will succeed in raising the wheel onto the curb when the force is applied (a) at the center ...

chemistry
How does Le Chatelier's principle explain the result you obtained after the addition of NaOH?

healthcare
treat them as if they were someone who is the same age as you.

Chemistry
when 0.20 mole HF is dissolved in water to a volume of 1.00 L, 5.8% of the HF dissociates to form F- (aq). What is the equilibrium constant for the reaction ? HF(aq) +H2O(l) ------ F- (aq) +H3O+ (aq)

trig
cos(sin^-1 x)=sq rt(1-x^2) prove the identity

trig
Give the following for the function: y=2+cos(5x+3.14 Amplitude: Period: Phase Shift:

Trig
A 7.25 inch circular saw blade rotates at 5200 revolutions per minute. a) Find the angular speed of the saw blade in radians per minute. b) Find the linear speed in feet per minute of one of the 24 cutting teeth as they contact the wood being cut.

MATH HELP
At Jefferson College 15% of all students participate in athletics. If a class consists of 33 randomly selected students, how many of them would you expect to participate in athletics?

Trig
A carousel with a 50-foot diameter makes 4 revolutions per minute. a) Find the angular speed of the carousel in radians per minute. b) Find the linear speed in feet per minute of the platform rim of the carousel.

Statistics
At the Starlight Jewelry store, the customer preferences for wedding bands is 60% yellow gold, 29% white gold and 11% platinum. If 15 customers are randomly selected, what is the probability that more than 10 of them choose yellow gold wedding bands?

Trig Circular Motion
A es004-1.jpginch circular saw blade rotates at 5200 revolutions per minute. a) Find the angular speed of the saw blade in radians per minute. b) Find the linear speed in feet per minute of one of the 24 cutting teeth as they contact the wood being cut.

Trig
A ferris wheel at the fair has a radius of 60 feet. If it takes 24 seconds to make a full revolution, what is the linear speed for the passengers?

Chem 2
Calculation in grams for a .100 M solution of NaC2H3O2 * 3H2O using a 100 mL volumetric flask?

chemistry
51.59 g of water at 82.6 oC is added to a calorimeter that contains 48.01 g of water at 40.9 oC. If the final temperature of the system is 59.4 oC, what is the calorimeter constant (Ccalorimeter) ? Use 4.184 J/goC for the heat capacity of water.

chem
How much energy (in Joules) is required to heat 13.48 g of water from 10.5 oC to 46.2 oC ? Use 4.184 J/goC as the specific heat capacity of water.

Physics
A mass of .27 kg is attached to a spring and is set into vibration with a period of .39s.what is the spring?

Chemistry
Solid ammonium nitrate can decompose to dinitrogen oxide gas and liquid water. What is delta G at 298K?

Math
If threr are a total of 20 students in Bibi's class, how many boys are in the class? How manygirls are in the class?

math- Variance
What does it mean when it says Variance of Stride Length with Speed?? Do you add the Variance of both individually together?

The sign would be larger. That is because inches are larger in size then centimeters. So the sign would be larger

math
I feel as though I am missing something here...Suppose a family wants to have 3 children. Find the probability that the family has at least 1 boy. Help?

math
I feel as though I am missing something here...Suppose a family wants to have 3 children. Find the probability that the family has at least 1 boy. Help?

Chemistry
1) find the concentration of H3O+ which is easy since you have the pH 2) find the number of moles of H3O+, remember c=n/v relationship 3) mole ratio! this gives you the number of moles of HCl present, it is a 1:1 ratio remember this from the chemical formula 4) Molarity of HCl...

Math
I have the same exact question as this. But I don't understand your way of answering. Can you please help me with this?# of faces painted 3x3x3 4x4x4 5x5x5 4 3 2 1 0

Social Studies
Did the Emperor of Qon's efforts to unite China make him an effective ruler? Is the answer very ineffective or very effectve?

Math
I forget how do you do this problem? -y < -x-2

physics
A car initially traveling eastward turns north by traveling in a circular path at uniform speed as in the figure. The length of the arc ABC is 214 m, and the car completes the turn in 40.0 s (Figure shows coordinate plane with point A on -y axis point C on +x axis and point B ...

Calculus I
Show that the equation x^4 + 4x + c = 0 has at most two real roots. I believe we're supposed to prove this by proof of contradiction using Rolle's Theorem, but I'm not quite sure how to do this problem.

algebra 2
A pebble is tossed from the top of a cliff. The pebble's height in feet is given by y(t) = -16t2 + 6t + 200, where t is the time in seconds. Its horizontal distance in feet from the base of the cliff is given by d(t) = 5t. How far will the pebble be from the base of the ...

Calculus I
Sketch the graph of f by hand and use your sketch to find the absolute and local maximum and minimum values of f. 18. f(x) = 1/x , 1 < x < 3 I can graph it just fine, but for my answer I got that the function has none of the above. Is this correct?

Algebra 2
If there are initially 1500 bacteria in a culture, and the number of bacteria double each hour, the number of bacteria after t hours can be found using the formula N=1500(2^t). How many bacteria will present after 7 hours? I think the answer is N=192,000. Is this correct?

math
i need help doing these type problems.... example 3 1/3- 2 1/2=

algebra
To solve ax = b for x multiply both sides of the equation by?

algebra
Hi would you help me homework please?

world history
Analyze the changes in global commerce between 1750 and 1900 due to changes in technology, communication, and economic theory.

math
I have 432 cards that are three and a half inches long if I put them end to end how many feet long is the line of cards

Calculus
Ahh yes that was a typo! Thank you!!

Calculus
Find the derivative of y = ln |cos(ln)|. I got -tan(ln x)/x, is this correct?

Physics
if a force of 163 newtons is applied to the end of the jack handle the end moves down 15 cm. If lifting part of the jac raises the car bumper 1.75 cm what force is the jack exerting on the bumper

College Chemistry
How much Ca(OH)2 is required to remove 90.0% of PO4^-3 from 7.5 times 10^6 L of drinking water containing 25 mg/l of PO4^-3?

Chemistry
How many milliliters of .100 M HNO3 are needed to neutralize 58.5 mL of .0100 Al(0H)3?

math
If there are 75 animals in a pet store and a pie graph shows 16% are cats how many of the animals are cats

Physics
A 80.0 N box of is pulled 20.0 m up a 30.0 Degree ramp by a force of 115 N, if the coefficient of kinetic friction between the box and the ramp is .22 what is the box's kinetic energy?

chemistry
Thanks dude

chemistry
The absorbance reading of an element is observed in an atomic absorption spectrometer. Would the readings increase, decrease or stay the same if: (please explain) Thank you a) viscosity of the solution increased or decreased? b) the solution had a lot of dust particles? c) the...

physics
A string connecting a car of mass x1 on an air track is connected to another mass, x2, by a string over a pulley. If the string has appreciable mass will the car still undergo constant acceleration? Explain I think that the car will still undergo constant acceleration, the ...

physics
A string connecting a car of a certain mass, x1, on an air track is connected to another mass, x2, by a string over a pulley. If the string has appreciable mass will the car still undergo constant acceleration? Explain. I think it will still undergo a constant acceleration, ...

physics
A string connecting a car of a certain mass, x1, on an air track is connected to another mass, x2, by a string over a pulley. If the string has appreciable mass will the car still undergo constant acceleration? Explain. I think it will still undergo a constant acceleration, ...

try this
what song is this from: Everybody seems to look at you, Its not because your different, its just because your so scay cool, the sinister style---------------, you dropped it gorgeous, dropped it gorgeous, that's where the cool kids rule!

TO WRITEACHER
i'm looking for steps to write a summary

TO WRITEACHER
it didn't help!

HELP!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
I need help on writing a summary and an example of a summary.My teacher said that when your writing a summary,the middle is the 3 supporting details or what happens,the end is what wraps it all up or the conclusion.but what is the beginning? PLEASE, I NEED HELP, MY ASSIGNMENT ...

Chemistry
Thanks so much :)

Chemistry
Consider the following hypothetical aqueous reaction: A (aq)-->B(aq)}. A flask is charged with 0.065 (mole) of A in a total volume of 100.0 (mL}. The following data are collected: Time (min) 0 10 20 30 40 Moles of A .065 .051 .042 .035 .031 Calculate the average rate of ...

trig
Find sin t,cos t and tan t when the terminal side of an angle of t radians passes through ( -3/5 , -4/5) on the unit circle.

geometry
If triangle has vertices A(7,-3), B(-1,5), and C(4,-8), what is the length, in simplest radical form, of the median from C to AB?

Calculus
Sorry, I forgot one: w) lim (1-2cos^2x)/(cosx-sinx) as x->π/4

Calculus
uu) lim ln(1-x) as x->1- yy) lim (√(6-x)-2)/(√(3-x)-1) as x-> 2 zz) lim (1-(1/2)arctanx) as x->-∞ bbb) lim ln|1-x| as x->1 If these are hard to interpret with all the parentheses, you can plug them in to Wolfram Alpha and it interprets them ...

Physics
An open tube of length L = 1.60 m and cross-sectional area A = 4.60 cm2 is fixed to the top of a cylindrical barrel of diameter D = 1.27 m and height H = 2.16 m. The barrel and tube are filled with water (to the top of the tube). Calculate the ratio of the hydrostatic force on...

physics
A 39-kg girl standing at rest on slippery (frictionless) ice throws a 10-g ball forward with a speed of 10 m/s. Just afterward, the girl will

Physics
In a 100 m race, Maggie and Judy cross the finish line in a dead heat, both taking 10.6 s. Accelerating uniformly, Maggie took 2.20 s and Judy 2.90 s to attain maximum speed, which they maintained for the rest of the race. A) What was Maggie's acceleration? B) What was ...

physics
A 5.50 bucket of water is accelerated upward by a cord of negligible mass whose breaking strength is 77.0 . If the bucket starts from rest, what is the minimum time required to raise the bucket a vertical distance of 14.0 without breaking the cord?

Calc 3
if r= <x,y,z> and r_0= <x_0,y_0,z_0>, describe the set of all points (x,y,z) such that magnitude[r-r_0]=4

Math
when he sits on the throne

Calculus I
Reading these answers makes a whole lot more sense after a night's sleep, haha. Thank you so much!

Calculus I
We're reviewing limits from the previous chapter, but I'm still having some difficulty with some problems: lim tan(pi(x/4)) as x-> -7 lim (x^2 - x^3(cos(1/x))/3x^2 as x-> 0 I know the answer to the first problem is 1 and to the second problem it's 1/3 but I&#...

Calculus
Since f is a polynomial, it is continuous in the interval [0,1]. f(0) = 3 f(1) = 9 Therefore, for every value of k in the interval [3,9] there is a c in the interval [0,1] such that f(c)=k.

English Lit
okay-thank you-I'll try again

English Lit
I have a question about Henry II. What did he do that solidified his power as king but led to economic problems and helped incite conflict with the church. The possible answers are: Executed all Bishops who were opposed to his rule Gave enormous finiacial gifts to the nobility...

SIMILARITY
WHAT ARE THE SIMILARITIES OF A PARK AND A PLAYGROUND?

SOSO
okay! but what are the similarities

SOSO
okay. THEY ARE DIFFERENT BECAUSE A PLAYGROUND IS A PLACE WITH SLIDES,SWINGS,MONKEY BARS,AND SEE-SAW WHERE KIDS CAN PLAY.A PARK IS AN OPEN AREA WITH BENCHES AND PONDS WHERE THERE IS A LOT OF FREE ROOM TO RUN.

SOSO
what ARE the similarites and differences between parks and playgrounds!

Physics
A high diver of mass 65.0 kg steps off a board 10.0 m above the water and falls vertical to the water, starting from rest. If her downward motion is stopped 2.30 s after her feet first touch the water, what average upward force did the water exert on her? I'm not sure how ...

Physics
How do you calculate the magnitude of the uncertainty of the net force, U{F}? I was given several different equations but for some reason I'm still confused. Any help would be greatly appreciated.

Physics
How do you calculate the magnitude of the uncertainty of the net force, U{F}? I was given several different equations but for some reason I'm still confused. Any help would be greatly appreciated.

Physics
Starting from rest, a 4.0-kg body reaches a speed of 8.0 m/s in 2.0 s. What is the net force acting on the body?

Physics
Starting from rest, a 4.0-kg body reaches a speed of 8.0 m/s in 2.0 s. What is the net force acting on the body?

Physics
A hunter wishes to cross a river that is 1.6 km wide and that flows with a speed of 4.8 km/h. The hunter uses a small powerboat that moves at a maximum speed of 9.6 km/h with respect to the water. What is the minimum time necessary for crossing?

TwinWin got it right. 100% correct.

physics
a car rolls off a cliff and lands 15m from the base. if the cliff was 22m high, how fast was the car going? show work.

physics
A 20000 kg airplane takes off by traveling 300 m down a runway while the engines exert a continuous force of 4000 N.(a) Calculate the change in kinetic energy of the airplane during takeoff.(b) Determine the speed of the airplane as it leaves the runway.

HELP
okeedokey

HELP
i need a printable protractor

Science
how is it possible to figure out a science problem like this EXAMPLE:s=2m*6Hz=2m*6(1/s)=12m/s if they don't tell you what the letters mean?

Geometry
MO bisects <LMN,m<NMO=(6x+19)°,andm<LMO=(9x-14)°. Solve for x and find <LMN.

Physics
644 lbs

math
kano's college is 1200 miles away.he drives 300 miles each day.how long will it take him to get to college? _______________________________________ days / miles per day /miles in all _______________________________________ 5 / 300 /1500 300*5 =1500 is the number model write?

stuff
is figure skating all season

math
How many 8 by 10 inch tiles fit on a 16 by 20 ft floor ?

math
what do the numbers 8/10,0.75,0.2 and 2/5 look like in order from least t greatest?

chemistry
don't know don't care

Math
A total number of 121 people came to the school science fair this year. This number is 7 MORE than TWICE the number of people who came last year's science fair. How many people came last year?

earth
what factors contribute to the formation of fertile, deep topsoil in temperate regions?

Physics
James's tug of war team pulls with 500N of force to the right wile Jake's team pulls with 415N to the left. If James's team weighs 350 kg, how fast are they moving?

physics
A lever has a Mechanical Advantage of 13. How much force would the lever exert if you push with a 200N force?

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