Friday

July 3, 2015

July 3, 2015

Total # Posts: 93

**Physics**

A typical tumor treated with radiotherapy may receive 400 Gy per 250g. How many disintegrations of caesium-137 atoms are required to provide that absorbed dose? Help would be appreciated!
*June 18, 2015*

**Math**

Find T 2200=7500/(1+9e^-o.o21972*T) Can I multiply both sides by 1+9e^-0.021972*T ?
*January 14, 2015*

**Algebra**

1.How do I find the center of a circle using the points (2,8) (-4,6) (1,-1) ? 2. The Radius of the circle? 3. Equation of circle THANKS!
*September 24, 2014*

**ENGLISH**

In "A Man Called Horse," After his wife leaves him, Yellow Robe Behaves recklessly in battle because he A. would rather die than live with the bitterness he feels as a result of his lost pride B. is trying to gain membership in the society known as the foxes C. ...
*May 28, 2014*

**statistics**

An investment broker reports that the yearly returns on common stocks are approximately normally distributed with a mean return of 12.4 percent and a standard deviation of 20.6 percent. On the other hand, the firm reports that the yearly returns on tax-free municipal bonds are...
*May 13, 2014*

**S.S redo**

8d 9c 10a 11b 12b
*March 12, 2014*

**S.S redo**

1d 2c 3b 4a 5b 6b 7c
*March 12, 2014*

**S.S redo**

1. The economic centers of the Northeast are the region's __________. (1 point) farms fisheries forests cities 2. Two major ports in the South are ______________________. (1 point) Atlanta and Dalton Raleigh and Austin Miami and New Orleans New York City and Philadelphia 3...
*March 12, 2014*

**S.S please help!**

Oops wrong questions! posting new ones right now!
*March 12, 2014*

**S.S please help!**

1d 2c 3b 4a 5b 6b 7c My answers
*March 12, 2014*

**S.S please help!**

1 Marks: 3 Which statement best describes the government of Canada? Choose one answer. a. The monarch of Britain has total control over Canada. b. The Canadian parliament is ruled by the United States. c. Canada has complete power over its own government. d. The prime minister...
*March 12, 2014*

**Algebra**

Jon and Melissa agree to meet in Chicago for the weekend. Jon travels 236 miles in the same time that Melissa travels 224 miles. If Jons rate of travel is 3 mph more than Melissas, and they travel the same length of time, at what speed does Jon travel?
*March 5, 2013*

**chemistry**

What is the molarity of 5g of O2 in 250 mL? Show work, please.
*December 12, 2012*

**math**

The quantity demanded x (in units of a hundred) of the Mikado miniature cameras/week is related to the unit price p (in dollars) by p = −0.2x2 + 80 and the quantity x (in units of a hundred) that the supplier is willing to make available in the market is related to the ...
*December 6, 2012*

**physics**

A spherical generator is used to produce a -15.00D surface on glass of refractive index 1.80. The diameter of the cutting tool is 80mm and the radius of the cutting surface is 4mm. What is the angle between the axis of the tool and the axis of the lens?
*October 28, 2012*

**Physics**

A spherical generator is used to produce a -15.00D surface on glass of refractive index 1.80. The diameter of the cutting tool is 80mm and the radius of the cutting surface is 4mm. What is the angle between the axis of the tool and the axis of the lens?
*October 28, 2012*

**MATH/PHYSICS**

1.) A bird can fly 20 km/h. How long does it take to fly 12 km?
*October 1, 2012*

**PHYSICS**

Vector V1 is 6.29 units long and points along the negative x axis. Vector V2 is 4.23 units long and points at +35.0° to the +x axis. (a) What are the x and y components of each vector? (b) Determine the sum V1 + V2.
*September 30, 2012*

**calculus**

I guess it's the format but I am little confused about what you did....
*June 24, 2012*

**calculus **

Can someone help me understand how to find the derivative of these two problems: (t^2-1/t^2+2)^3=y and y=sin^32x? I think with the first one, I could just foil it maybe and cancel but I don't know what to do with the ^3...and then the second one I haven't gotten the ...
*June 24, 2012*

**math**

I have to evaluate the limit of these problems and I can't figure them out! 1.) Lim x-> 1 x^2+x-2/x^2-x 2.) (please note that the -2 is not under the square root) Lim x->0 sqroot 4+h -2/ h
*June 18, 2012*

**Algebra 2**

log4 (x-2) - log4 (x+1) = 1
*June 13, 2012*

**Algebra 2**

log x 8 = 2
*June 13, 2012*

**Chemistry**

oops the equation is actually 2SO2 (g) + O2 (g) yield 2SO3 (g) the yield part was an arrow facing both directions, not just the product side
*June 3, 2012*

**Chemistry**

Consider the following equilibrium at 1000K: 2SO2 (g) + O2 (g) ¡ê 2SO3 (g) A study of this system reveals that there are 3.5E-3 moles of sulfur dioxide gas, and 4.8E-3 moles of oxygen gas present in a 11.0L flask at equilibrium. The equilibrium constant for this ...
*June 3, 2012*

**Math**

Change into standard form 1. x^2+6x+4y+5=0 2. y^2+12x+2y+=-25
*May 7, 2012*

**Math**

Write the standard equation of the ellipse with the given characteristics Vertices: (0,7) (0,-7) foci: (0,2) (0,-2)
*May 7, 2012*

**math**

Suppose $5000 is deposited in a bank account that compounds interest four times per year. The bank account contains $9900 after 13 years. What is the annual interest rate for this bank account? i already set it up but i don't know where to go from there. Please help
*April 9, 2012*

**Physics**

I do not understand the part in which you solve for x. Is it supposed to be the cos of 60 equals x divided by .2?
*November 14, 2011*

**Physics**

The three 500 g masses in the daigram are connected by massless, rigid rods to form a triangle. What is the triangle's rotational energy (in J) if it rotates at 1.50 rev/s about an axis through the center? (Diagram shows equilateral triangle with 500g masses at each point...
*November 14, 2011*

**chemistry**

I actually just redid it and found something close to 9.21?
*October 3, 2011*

**chemistry**

omg, thank u! I ended up getting something 1.70! THANKS!
*October 3, 2011*

**chemistry**

How many grams of NAC2H3O2 must be dissolve in enough water to prepare 250.0 mL of a solution with a pH= 9.200? Molar mass of NaC2H3O2 ia 82.03 g/mol. Ka for C2H3O2H is 1.8x10^-5
*October 3, 2011*

**math**

i'm having trouble with this math equation 5/2x^2-1/2^4 (need to find greatest common factor)
*May 19, 2011*

**CHEMISTRY**

ETHANOL (C2H5OH) HAS A DENSITY OF 0.80g/ml. IF A 10%(v/v) MIXTURE OF ETHANOL IN WATER WAS PREPARED HOW MANY GRAMS OF ETHANOL WOULD BE IN 100ML OF THE MIXTURE? (ASSUMING MIXED VOLUME IS THE SUM OF THE PARTIAL VOLUME)
*April 25, 2011*

**Science/Math**

Hello, Suppose that a newly discovered element called centium has three isotopes that occur in nature. These are centium-200, centium-203, and centium-209. Assume that these isotopes occur in equal amounts in nature. What will be the average atomic mass of this element?
*April 13, 2011*

**Math**

Write and equation to match the problem situation below. Callie has 4 rimes as many CDs as she has DVDs. She has a total of 60 CDs and DVD. How many dvds, d, does callie have?
*February 22, 2011*

**chemistry**

when water is combined with magnesium nitride to produce magnesium hydroxide and ammonia gas, is this reaction endothermic or exothermic and why?
*January 25, 2011*

**chemistry**

when water is combined with magnesium nitride to produce magnesium hydroxide and ammonia gas,
*January 25, 2011*

**Math**

c - 1/4c = 49.95
*January 23, 2011*

**Math**

2/7 k - 1/14 k = -3 does k= -42?
*January 23, 2011*

**Math!**

x/4 - 3x/2 = -1/2 I do not understand at all
*January 23, 2011*

**Math**

Luke bought some things at the store. He paid $5.98 for a pizza, $3.75 for a case of dr.pepper, $2.50 for a box of brownie mix. And $1.01 in sales tax. What information is needed to find Lukes correct change?
*December 6, 2010*

**MATHE HELP!**

Write an expression that can be used to find the average if these numbers: 7, -2, 10, -4, -9
*December 6, 2010*

**Math**

Maratha bakes between 4 1/4 and 9 3/4 hours each day at her bakery. About how many hours does she spend baking in one week?
*December 6, 2010*

**MATH**

A triangle with two congruent sides and two angles that both measure 45 is a.scalene and right b.isosceles and acute c.isosceles and right d. Equilateral and acute
*December 5, 2010*

**Math Please Help**

Oh sorry I meam two angles that are complementary have s sun of 45
*December 5, 2010*

**Math Please Help**

D?
*December 5, 2010*

**Math Please Help**

Which statement is not true? Two or angles that are supplementary have a sum of 180 or Two angles that are complementary have a sum ot 45
*December 5, 2010*

**Math**

Which of the following shapes could not represent a top, front, or side view of a pentagonal prism? a. A pentagon b. A triangle c. A square d. A rectangle
*December 5, 2010*

**Math Please Help**

Ok I get it. Thank you!!!
*December 5, 2010*

**Math Please Help**

But that equals 24 and that not a answer on the thing
*December 5, 2010*

**Math Please Help**

3/2 = .6 repaeating x 16 = 10.6 repeating and 16/1 x 2/3 = 10.6 reapeating
*December 5, 2010*

**Math Please Help**

I got 10 something but it's not one of the answers
*December 5, 2010*

**Math Please Help**

how?
*December 5, 2010*

**Math Please Help**

could I do it in a proportion?
*December 5, 2010*

**Math Please Help**

The premiters of two equilateral triangles are in the ratio 2:3. If the perimeter of the smaller triangle is 16 cm what is the measure of a side of the larger triangle?
*December 5, 2010*

**physics**

A 66.0 kg man is ice-skating due north with a velocity of 5.70 m/s when he collides with a 36.0 kg child. The man and child stay together hand have a velocity of 2.20 m/s at an angle of 33.0° north of east immediately after the collision. What was the velocity of the child...
*November 22, 2010*

**physics**

I tried this and got 118882 for Va' and 390097 for Va but it was wrong?
*November 21, 2010*

**physics**

An alpha particle collides with an oxygen nucleus, initially at rest. The alpha particle is scattered at an angle of 60.9° above its initial direction of motion, and the oxygen nucleus recoils at an angle of 51.9° on the opposite side of that initial direction. The ...
*November 21, 2010*

**Chemistry**

Thank you! what is the 2257 from?
*November 8, 2010*

**Chemistry**

If 1.10 g of steam at 100.0 degrees celsius condenses into 38.5 g of water, initially at 27.0 degrees celsius, in an insulated container, what is the final temperature of the entire water sample? Assume no loss of heat into the surroundings
*November 8, 2010*

**physics**

A horizontal rifle is fired at a bull's-eye. The muzzle speed of the bullet is 795 m/s. The barrel is pointed directly at the center of the bull's-eye, but the bullet strikes the target 0.042 m below the center. What is the horizontal distance between the end of the ...
*October 13, 2010*

**physics**

A golfer imparts a speed of 32.1 m/s to a ball, and it travels the maximum possible distance before landing on the green. The tee and the green are at the same elevation. (a) How much time does the ball spend in the air? (b) What is the longest "hole in one" that the...
*October 12, 2010*

**College Calculus 1**

A runner sprints around a circular track of radius 150 m at a constant speed of 7 m/s. The runner's friend is standing at a distance 300 m from the center of the track. How fast is the distance between the friends changing when the distance between them is 300 m? (Round to...
*October 1, 2010*

**Science**

The Ruby Throated Hummingbird has a resting heart rate of 250 beats per minute. When it is threatened or chased, it's heart rate can reach 1200 beats per minute. Predict its lifespan and justify your explanation.
*May 3, 2010*

**Science**

The Ruby Throated Hummingbird has a resting heart rate of 250 beats per minute. When it is threatened or chased, it's heart rate can reach 1200 beats per minute. Predict its lifespan and justify your explanation.
*May 3, 2010*

**Science/Math**

The Ruby Throated Hummingbird has a resting heart rate of 250 beats per minute. When it is threatened or chased, it's heart rate can reach 1200 beats per minute. Predict its lifespan and justify your explanation.
*May 3, 2010*

**Math**

I need to know how to write an equation for the horizontal line with the points of ( -2, -5). I understand that it should be written as y=k. So would it be, y=-2x-5 or would it be y=-5? Where do you find k?
*January 17, 2010*

**MATH**

The total sales made by a salesperson was $25,000 after 3 months and $68,000 after 23 months. Predict the total sales after 42 months.
*January 17, 2010*

**Advanced Functions**

Rena has been offered entry-level positions with two firms. Firm A offers a starting salary of $40 000 per year, with a $2000 per year increase guaranteed each subsequent year. Firm B offers a starting salary of $38 500, with a 5% increase every year after that. a)After how ...
*December 13, 2009*

**prob and stats**

A test is conducted in 22 cities to see if giving away free transit system maps will increase the number of bus riders. In a regression analysis, the dependent variable Y is the increase in bus riders (in thousands of persons) from the start of the test until its conclusion. ...
*December 9, 2009*

**Prob and Stats**

In a multiple regression with 5 predictors in a sample of 56 U.S. cities, what would be the critical value for an F test of overall significance at a= .05? A. 2.45 B. 2.37 C. 2.40 D. 2.56
*December 9, 2009*

**math**

1 + ((2*3)/4) =2.5
*December 9, 2009*

**chemistry lab repost**

i need help locating a lab for regents chemistry. i have the data sheet but misplaced the rest of the lab. i know it's online somewhere, but i'm not sure which lab it is.. (what it is called). The data sheet has 3 charts on it, 1 titled 'solubility'. it ...
*March 15, 2009*

**chemistry**

Nevermind. 1 m = 100 cm. I got confused. Thank you.
*December 12, 2008*

**chemistry**

How? 1000 * 1000 = 1 million.
*December 12, 2008*

**chemistry**

1 km = ? cm. I was thinking 1,000,000. Could someone double check that?
*December 12, 2008*

**physics**

A tourist being chased by an angry bear is running in a straight line toward his car at a speed of 4.38 m/s. The car is a distance d away. The bear is 25.4 m behind the tourist and running at 5.88 m/s. The tourist reaches the car safely. What is the maximum possible value for ...
*December 11, 2008*

**physics**

A boat travels at 3.8 m/s and heads straight across a river 240 m wide. The river flows at 1.6 m/s. Find A) The boat's resultant velocity. B) How long it takes the boat to cross the river. C) How far downstream the boat is when it reaches the other side. Please help, i ...
*November 2, 2008*

**chemistry**

i keep trying to do these problems and i don't understand them. please help me!! 1. Gas stored in a tank at 273 K has a pressure of 388 kPa. The save limit for the pressure is 825 kPa. At what temperature will the gas reach this pressure? A. 850 K B. 925 K C. 580 K D. 273 ...
*October 10, 2008*

**microeconomics**

When deriving an individuals demand curve how do you find the optimal bundle if you are only given: price of 2 goods and income. i.e- price of wine: $35 price of beer: $12 Income= $419
*October 6, 2008*

**microecomomics**

When deriving an individuals demand curve how do you find the optimal bundle if you are only given: price of 2 goods and income. i.e- price of wine: $35 price of beer: $12 Income= $419
*October 5, 2008*

**why won't anybody help me**

The region R, is bounded by the graphs of x = 5/3 y and the curve C given by x = (1+y^2)^(1/2), and the x-axis. a) Set up and evaluate an integral expression with respect to y that gives the area of R. b) Curve C is part of the curve x^2 - y^2 = 1, Show that x^2 - y^2 = 1 can ...
*March 2, 2008*

**MATH-HELP!**

The region R, is bounded by the graphs of x = 5/3 y and the curve C given by x = (1+y^2)^(1/2), and the x-axis. a) Set up and evaluate an integral expression with respect to y that gives the area of R. b) Curve C is part of the curve x^2 - y^2 = 1, Show that x^2 - y^2 = 1 can ...
*March 2, 2008*

**math**

The region R, is bounded by the graphs of x = 5/3 y and the curve C given by x = (1+y^2)^(1/2), and the x-axis. a) Set up and evaluate an integral expression with respect to y that gives the area of R. b) Curve C is part of the curve x^2 - y^2 = 1, Show that x^2 - y^2 = 1 can ...
*March 2, 2008*

**Calculus**

So sales must increase at a rate of 300 books per week. Thank U So much! im gonna work on the second half of the problem now.
*November 25, 2007*

**Calculus**

ok i redid it so q'=300?
*November 25, 2007*

**Calculus**

Ok $3000 is the rate at that the revenue is rising. Ok for the second answer i plugged it in and i got 30=q'
*November 25, 2007*

**Calculus**

ok i got p=20 p'=-1 q=1000 q'=200 and when i plugged them in i got r'=3000 is that right?
*November 25, 2007*

**Calculus**

R'=p'(q)+p(q')
*November 25, 2007*

**Calculus**

R=p*q
*November 25, 2007*

**Calculus**

i am a different person and i still do not understand it i get R'=3000-400X but i dont understand wat to do with the 5000
*November 25, 2007*

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