# Posts by Leanna

Total # Posts: 118

math
You find a sales receipt from a store that shows the total price as \$40, and the total amount paid including sales tax as \$42. a. Write an equation you can use to find the sales tax rate which is r. what is the equation so I tried all things I could think of but it doesn't...

Calculus
A smokestack deposits soot on the ground with a concentration inversely proportional to the square of the distance from the stack. With two smokestacks d miles apart, the concentration of the combined deposits on the line joining them, at a distance x from one stack, is given ...

Calculus
The table below shows some values of a linear function f and an exponential function g. Fill in exact values for each of the missing entries. X 0 1 2 3 4 f(x) 25 375 g(x) 25 375

Calculus
Suppose that f(t)=Qoa^1=Qo(1+r)^t with f(4)=72.2 and f(10)=176.7. Find what a is and what r is.

Chemistry
A sample of nitrogen gas was collected via water displacement. Since the nitrogen was collected via water displacement, the sample is saturated with water vapor. If the total pressure of the mixture at 21 °C is 1.16 atm, what is the partial pressure of nitrogen? The vapor ...

Chemistry
A sample of nitrogen gas was collected via water displacement. Since the nitrogen was collected via water displacement, the sample is saturated with water vapor. If the total pressure of the mixture at 21 °C is 1.16 atm, what is the partial pressure of nitrogen? The vapor ...

math
Lee wants to cut this piece of canvas into two rectangles that are 3×2 and 3×5. He wants the sum of the two small recyangles to be the same as the area of the large rectangle. Can he do this? Explain the rectangle is 6feet across and 3feet tall

Chemistry :/
Formulas for experiment 1: CuSO4*5H2O CuSO4.XH2O --------> CuSO4 + XH2O Formulas for experiment 2: MgCl2·6H2O MgCl2 * X H2O = MgCl2 + X H2O I just need someone to check my answers please :)

Chemistry :/
These are the calculations I can up with for experiment 1: a:mass of water in the hydrate sample (g) 1.804g b:number of moles of water in the sample 0.100g c:mass of pure salt in the sample (g) 3.196g d:number of moles of salt in the sample .0214g e:molar ratio of water to ...

Chemistry :/
Experiment 1 results: mass of crucible 88g mass of hydrate 93g mass of salt 91.196g 1. Calculate the following: a:mass of water in the hydrate sample (g) b:number of moles of water in the sample c:mass of pure salt in the sample (g) d:number of moles of salt in the sample e:...

Chemistry
Experiment 1 results: mass of crucible 88g mass of hydrate 93g mass of salt 91.196g 1. Calculate the following: a:mass of water in the hydrate sample (g) b:number of moles of water in the sample c:mass of pure salt in the sample (g) d:number of moles of salt in the sample e:...

Physics
Two 2.9-cm-diameter electrodes with a 0.15-mm-thick sheet of Teflon between them are attached to a 9.0 V battery. Without disconnecting the battery, the Teflon is removed. a) What are the electric field after the Teflon is removed?

Art
I'm in art and i cant draw a bear do you have any tips?

math
I im learningabout fractions is there an faster or easier way i can do them?

math
OH THATS EASY XD well how much is in a millimeter? you need to find that out then..............yea that's all i got i think you x the number of what you got of the milliter and x it by 30

Physics
Suppose you wish to make a vertical leap with the goal of getting your head as high as possible above the ground. At the top of your leap, your arms should be... a. held at your sides. b. raised above your head. c. outstretched, away from your body.

Physics
A combination lock has a 1.2 cm -diameter knob that is part of the dial you turn to unlock the lock. To turn that knob, you grip it between your thumb and forefinger with a force of 0.62 N as you twist your wrist. Suppose the coefficient of static friction between the knob and...

Physics
A combination lock has a 1.2 cm -diameter knob that is part of the dial you turn to unlock the lock. To turn that knob, you grip it between your thumb and forefinger with a force of 0.62 N as you twist your wrist. Suppose the coefficient of static friction between the knob and...

Physics
1. At what height above the earth is the free-fall acceleration 30% of its value at the surface? 2. What is the speed of a satellite orbiting at that height?

Physics
The ultracentrifuge is an important tool for separating and analyzing proteins in biological research. Because of the enormous centripetal accelerations that can be achieved, the apparatus must be carefully balanced so that each sample is matched by another on the opposite ...

Physics
A conical pendulum is formed by attaching a 0.60kg ball to a 1.0m -long string, then allowing the mass to move in a horizontal circle of radius 30cm. 1. What is the tension in the string 2. What is the ball's angular velocity in rpm?

Physics
A fast-moving superhero in a comic book runs around a circular, 70-m-diameter track five and a half times (ending up directly opposite her starting point) in 3.0s. What is her angular speed, in rad/s?

Physics
A 20 kg crate is placed on a horizontal conveyor belt. The materials are such that us = 0.47 and uk = 0.21. What is the maximum acceleration the belt can have without the crate slipping? If acceleration of the belt exceeds the value determined in part A, what is the ...

Physics
(23kg)(9.8m/s^2)(cos(38)) = 177.6N

Physics
A 23 kg child goes down a straight slide inclined 38 degrees above horizontal. The child is acted on by his weight, the normal force from the slide, and kinetic friction.

math
when a ball is dropped, it bounces back up 4/5 of the height from the height it was dropped.If the ball dropped from a height of 200cm, how high does it go after bouncing twice.

math
a woman had 400 oranges in a basket. after selling 1/5 of them, she found that 1/8 of the remainder were bad. how many of the remainder were good?

math
how do you write 4/5, 5/12, 3/10 in its simpliest form?

algebra
The cost in dollars, C, of renting a carpet cleaner is given by the linear equation C = 20 + 25x, where x is the number of days. Use this model to find the cost of renting the unit for 11 days.

Math
There are 144 perfect pumpkins.

Science Help!
How much heat is needed to cause the following irreversible reaction? 200 g of liquid H2O at 50°C is heated to form 200 g of steam at 120°C

Organic Chemistry
I have the linear formula of CH3CH2OLi and I'm trying to draw the structure with charges. Not really sure how. Please help.

Math
The size of a bacteria population is given by P=C*e^(kt) Where C is the initial size of the population, k is the growth rate constant and t is time in minutes. a) If the bacteria in the population double their number every minute, what is the value of k? I need help please!

social studies
How did minoans and Mycenaeans make a living? Who was Socrates most well known student? What was the name of the book plato wrote?

Probability
With her box of 64 crayons, your little sister decides to draw a picture of the family: herself, you, and your parents. How many different ways could she find to give you all hair colors?

Probability
With her box of 64 crayons, your little sister decides to draw a picture of the family: herself, you, and your parents. How many different ways could she find to give you all hair colors?

Biology
The options are: 3.549 g 35.49 g 35.49 mg 0.1 g 0.1 mg

Biology
You are supposed to add 0.1 mol of a substance with molecular weight = 354.9 to 1 liter of water. How much should you add? Choose one.

Biology
In goats, the allele for black hair is dominant to that for red. Two black haired goats mated, producing twelve offspring. Of the first eleven, 8 had black hair and 3 had red hair. What is the probability of the twelfth offspring having red hair?

Grammar MT
It actually depends on account instructions on dropping the 's. Both are correct.

Calc
When pi/2<theta<3pi/4, which of the following could possibly be tan theta. a. -8 b. -1/8 c. 0 d. 1/8 e. 8

Calc
Thank you so much!

Calc
I need help solving this problem. logbase5(x+2)=2

Calculus
Thanks for help on 1. on 2. if i do u=sqrt(x) my du is 1/2x^(-1/2) and that means my du is in the denominator. So it would read 2integral of sin(u)/du

Calculus
I don't know how to do the integral of e^(lnx^2)dx and the integral of (sin sqrtx)/(sqrtx) dx

Calculus
oh wow thank you so much!! that makes sense!!

Calculus
i know that the derivative of that is 1/2x^(-1/2) i still don't know what to do

Calculus
I need help with integrals and I need help with the problem. Integral of 4/sqrt(x)dx

Algebra
How do you do long division of ((5x^4)-2)/(3x^2) _______ 3x^2|5x^4-2

AP Calculus
I previously posted this but had a mistake in it. Determine dy/dx if xsiny=arctany i did (x)(cosy dy/dx)+(1)(siny)=dy/(1+y^2) so far

AP Calculus
Determine dy/dx if xsiny=artany i did (x)(cosy dy/dx) so far

chem
a 275mL sample of vapor in equilibrium with 1-propylamine at 25C is removed and dissolved in 0.500L of H20. For 1-propalamine, Kb=3.72*10^-4 and the vapor pressure at 25C is 215 torr. (a)What should be the pH of the aqueous solution? (b) How many mg of NaOH dissolved in 0.500L...

AP Calculus
Find the total area enclosed by the graph of y=(e^sinx)*(cosx) and the x-axis from x=0 to x=pi I got .0563331993 but when I checked it graphically I got 3.22765

Calculus
Let f be the function defined for x >or= to 0 with f(0)=5 and f', the first derivative of f, give by f'(x)=e^(-x/4)sin(x^2). A) Use the graph of f' to determine whether the graph of f is concave up, concave down, or neither on the interval 1.7<x<1.9. ...

Calculus
A cubic polynomial function f is defined by f(x) = 4x^3 + ax^2 + bx + k? A cubic polynomial function f is defined by: f(x) = 4x^3 + ax^2 + bx + k where a, b, and k are constants. The function f has a local minimum at x= -1, and the graph of f has a point of inflection at x= -2...

Calculus
A cubic polynomial function f is defined by f(x) = 4x^3 + ax^2 + bx + k? A cubic polynomial function f is defined by: f(x) = 4x^3 + ax^2 + bx + k where a, b, and k are constants. The function f has a local minimum at x= -1, and the graph of f has a point of inflection at x= -2...

Calculus
Let f be a twice-differentiable function such that f(2)=5 and f(5)=2. Let g be the function given by g(x)= f(f(x)). (a) Explain why there must be a value c for 2 < c < 5 such that f'(c) = -1. (b) Show that g' (2) = g' (5). Use this result to explain why there...

Physics
Is 3 True? or is the answer 9.80?

Physics
So for each of the statements we have to write true or rewrite the part in Caps to make the sentence true. I'm only stuck on a couple. 1. On a position-time graph, the average velocity equals the run MULTIPLIED by the rise. 2. A child drops a ball. The instantaneous ...

AP Calculus
Thank you so much! It makes perfect sense and when I calculated it, it matched up.

AP Calculus
Consider the curve given by x^2+4y^2=7+3xy a) Show that dy/dx=(3y-2x)/(8y-3x) b) Show that there is a point P with x-coordinate 3 at which the line tangent to the curve at P is horizontal. Find the y-coordinate of P. c) Find the value of d^2y/dx^2 (second derivative) at the ...

General Chemistry II
A quantity of ice at 0 degrees celcius is added to 64.3 grams of water in a glass at 55 degrees celcius. After the ice melted, the temperature of the water in the glass was 15 degrees celcius. How much ice was added? The heat of fusion of water is 6.01kJ/mole and the heat of ...

Calculus
Find all points on the graph of f(x)=xe^x at which the tangent line is parallel to the line y-3x=4. i figured out that f'(x)=3 but i don't know what to do with that.

Calculus
Find all points on the graph of f(x)=xe^x at which the tangent line is parallel to the line y-3x=4. i figured out that f'(x)=3 but i don't know what to do with that.

Calculus - Still Need Help! Anyone!
A particle moves along the x-axis with position at time t given by x(t)=e^(-t)sin(t) for 0 is less than or equal to t which is less than or equal to 2 pi. a) Find the time t at which the particle is farthest to the left. Justify your answer I think you have to find the prime ...

Calculus!!!!
A particle moves along the x-axis with position at time t given by x(t)=e^(-t)sin(t) for 0 is less than or equal to t which is less than or equal to 2 pi. a) Find the time t at which the particle is farthest to the left. Justify your answer I think you have to find the prime ...

Calculus
A particle moves along the x-axis with position at time t given by x(t)=e^(-t)sin(t) for 0 is less than or equal to t which is less than or equal to 2 pi. a) Find the time t at which the particle is farthest to the left. Justify your answer I think you have to find the prime ...

mumford
You can do this on a calculator. for y put x-11 and see if its linear. To evaluate just plug 4 for x so it would read f(4)=4-11=-7

Calculus
A particle moves along the x-axis with position at time t given by x(t)=e^(-t)sin(t) for 0 is less than or equal to t which is less than or equal to 2 pi. a) Find the time t at which the particle is farthest to the left. Justify your answer I think you have to find the prime ...

THANK YOU SO MUCH!

We have to find out which of these statements are true. I narrowed it down to 2 answers. a) if f"(0)=0, the the graph of f changes concavity at x=0 b) If the function f is continuous on the interval [a,b] and the integral from a to b of f(x)dx=0, then f must have at least...

We have to pick which sentence the vocabulary word is used incorrectly. Vocab Word: Verity a) Many people trusted the VERITY of the accused spies Ethel and Julius Rosenberg, but the defendants were convicted and executed for espionage in 1953. b) Although neutrons and protons ...

ok here's what my workbook says Circle the letter of the best synonym for the word(s) in bold-faced type. INCUMBENT UPON all officials (incumbent upon is bold-faced.. these are the options a) the parameters of b) the duty of c) the term of office of d) the puissance of e) ...

We have to find the synonym of the word in bold. I have a few choices but I'm stuck between two.. The words in bold are incumbent upon the phrase reads: incumbent upon all officials Deciding to choose between a) the duty of b) the term of office of

algebra

When a ball is thrown straight down from the top of a tall building, with initial velocity 30 ft/sec, the distance from the release point at time t in seconds is given by s(t)=16t^2+30t. If the release point is 300 ft above ground, what is the velocity of the ball at the time ...

Calculus
When a ball is thrown straight down from the top of a tall building, with initial velocity 30 ft/sec, the distance from the release point at time t in seconds is given by s(t)=16t^2+30t. If the release point is 300 ft above ground, what is the velocity of the ball at the time ...

Thank you so much bobpursley!!!

It says find the numbers, if any, at which the given function is discontinuous. f(x)=abs(x+2) *abs - absolute value f(x)=e^xsinx for both of these problems i saw that it was continuous but i don't really know

Calculus
It says find the numbers, if any, at which the given function is discontinuous. f(x)=abs(x+2) *abs - absolute value f(x)=e^xsinx for both of these problems i saw that it was continuous but i don't really know

Factor x^2+x+12 now

US Government
Society operates more efficiently if government power is centralized. What reasons exist for continuing federalism in its current form? In other words, defend a federal system of government.

English - Beowulf
So we just started reading Beowulf at school and we're around ch 8. Our question to answer was Whose account of Beowulf and Brecca's swimming match is more credible/believable and why? This is referring to Unferth's and Beowulf's stories. I said that Beowulf ...

College Chemistry
I got the following, but I'm not sure if I did it correctly: 2Fe(OH)3 + 3OCl- ->2FeO4-2 + 3Cl- + 4H+ + H2O If someone could let me know whether I solved it correctly or not, that'd be nice. :)

American Government
I have to do a 5 minute presentation on George Washington and I have to focus on his contributions towards the Constitution. All the sites I go to have pretty much the same information. Does anyone have sites that could help me?

Calculus, need help again...
If the function f is defined by f(x)=x^2-2x, find limit h->0 (f(3+h)-(f(3-h))/2h

Caclulus, bobpursley HELP!
Sorry for bothering you on this one question but I just replied to my original problem if you could help me with that.

Calculus, bobpursley!
Oh I just replied again.

Calculus, bobpursley!
This has to do with my last Calculus problem. I need help on it..The part I replied to after you answered the question.

Calculus
(f(3+h)-(f(3-h))/2h I put a minus sign because it has a negative in front of the f(3-h) so it's -(f(3-h))

Calculus
Thank you for your help! For the second part I thought it would be -(9+6h-h^2)-6+2h?

Calculus
If the function f is defined by f(x)=x^2-2x, find limit h->0 (f(3+h)-(f(3-h))/2h

Calculus..Need Help Soon
If the solutions of f(x)=0 are 1 and -2, then the solutions of f(2x)=0 are a)1 and 2 b) 1/2 and -1 c) 2 and -4 d)-2 and 4 2)-1/2 and -1

Calculus..Need Help Soon
If f(x)=1-x^3 and f^-1 is the inverse of f, how many solutions does the equation f(x)=f^-1(x) have? a)none b)one c)three d)five e)six

Calculus..Need Help Soon
If x=1 and x=2 are zeros of f(x)=3X^3+Ax^2+Bx+2, then the value of A+B is a)1, b)-1, c)9, d)-9, e) cannot be determined I think it can't be determined but i don't know!

Math
A rational function g has the lines x=2 and x=-2 as vertical asymptotes, the line y=4 as a horizontal asymptote, and numbers 3 and 1 as zeros. Find a formula for g(x). So I got g(x)=(4x^2-16x+12)/(x^2-4) Is this correct

Calculus (Reiny or MathMate)
A rational function g has the lines x=2 and x=-2 as vertical asymptotes, the line y=4 as a horizontal asymptote, and numbers 3 and 1 as zeros. Find a formula for g(x). So I got g(x)=(4x^2-16x+12)/(x^2-4) Is this correct

Calculus
A rational function g has the lines x=2 and x=-2 as vertical asymptotes, the line y=4 as a horizontal asymptote, and numbers 3 and 1 as zeros. Find a formula for g(x). So I got g(x)=(4x^2-16x+12)/(x^2-4) Is this correct Math Mate?

Calculus
ok, so i got e^-7 and e^2 does that mean i reject e^-7 because its less than or equal to 0?

Calculus
Solve for x if 5+lnx=14/lnx.

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