# Posts by Jack

Total # Posts: 1,754

**Mayans and aztecs**

how did the aztecs acquire most new pieces of land

*September 6, 2010*

**Chemistry**

Are significant figures relevant in temperature? ex: (-459 *F - 32 *F)(5 *C/ 9 *F) = -272.78 *C So would I leave my answer as -272.78 *C? or -273 *C because of significant figures?

*August 31, 2010*

**Chemistry**

Are significant figures relevant in temperature? ex: (-459 *F - 32 *F)(5 *C/ 9 *F) = -272.78 *C So would I leave my answer as -272.78 *C? or -273 *C because of significant figures?

*August 31, 2010*

**math**

find the range of the function. g(x) = 5 + (square root of) (4 - x) please show all steps.

*August 28, 2010*

**Math**

Solve the following equation. 4.7 = 1.13x^2 Do i square root the 1.13x^2 first? or divide both sides by 1.13?

*August 28, 2010*

**5th grade math**

what is 2 to the first and second power? component problem

*August 26, 2010*

**math**

It took a faster runner 10 sec. longer to run a distance of 1500 m than it took a slower runner to run a distance of 1000 m.If the rate of the faster runner was 5 m/sec more than the rate of the slower runner,what was rate of each?

*August 23, 2010*

**math**

which has greater volume? a) 1.0 kg of feathers or 1.0 kg of lead b) 100 g of gold or 100 g of water c) 1.0 L of copper or 1.0 L or mercury

*August 23, 2010*

**math**

write 480 in a) 1 significant figure b) 2 significant figures c) 3 significant figures d) 4 significant figures

*August 23, 2010*

**math**

what is the role of derrivatives in the subjects other than mathematics.

*August 21, 2010*

**5th grade English**

However, misfortune and trouble did not stop Ray Charles. Subject=misfortune, trouble Verb= did stop

*August 20, 2010*

**Math**

A pair of fair dice is rolled. Let E denote the event that the number landing uppermost on the first die is a 3, and let F denote the event that the sum of the numbers landing uppermost is 6. Determine whether E and F are independent events

*August 15, 2010*

**math**

corp provides issuance of 200,000 shares of common stock. 40,000 shares were originally issued and 500 were reacquired. What is the number of shares outstanding?

*August 9, 2010*

**math**

corp provides issuance of 200,000 shares of common stock. 40,000 shares were originally issued and 500 were reacquired. What is the number of shares outstanding?

*August 9, 2010*

**physics**

"A one meter board with uniform density, hangs in static equilibrium from a rope with tension T. A weight hangs from the left end of the board 0.2m away in distance. What is the mass of the board"

*July 30, 2010*

**MATH**

1/2, 3/4, 3/8

*July 20, 2010*

**MATH**

FIND THE L.C.D. OF EACH AND EXPRESS THE FRACTIONS OF EACH IN TERMS OF THE L.C.D.

*July 20, 2010*

**Chemistry**

107.8?????

*July 19, 2010*

**algebra**

solve by multiplication -7/8x = -9/10

*July 8, 2010*

**math**

the equation is actually 2t^3-4t^2+3

*June 21, 2010*

**math**

Consider the function defined below. y = 2t3 - 4t2 + 3 (a) Calculate the second derivative. y '' = (b) Calculate the third derivative. y ''' =

*June 21, 2010*

**math**

which one is part a and part b.

*June 21, 2010*

**Statistics**

Total plasma volume is important in determining the required plasma component in blood replacement theory for a person undergoing surgery. Plasma volume is influenced by the overall health and physical activity of an individual. Suppose that sample of 61 male firefighters are ...

*June 20, 2010*

**Statistics**

Assuming that the heights of college women are normally distributed with mean 62 inches and standard deviation 3.5 inches, what percentage of women are between 58.5 inches and 72.5 inches? 34.1% 84.0% 15.7% my answer was 13.6 13.6% is this correct 97.6%

*June 20, 2010*

**Statistics**

x=3-0 . What percentage of the area under the normal curve lies to the left of ( 16.0% 15.80% 2.50% 0.50% having trouble with this my answer was 15.00% 0.15%

*June 20, 2010*

**physics**

A ball is launched from ground level at 31.8 m/s at an angle of 35° above the horizontal. How far does it go before it is at ground level again? A) 14 m B) 21 m C) 43 m D) 86 m E) 97 m

*June 10, 2010*

**physics**

A ball is rolled horizontally off a table with an initial speed of 4.0 m/s. A stopwatch measures the ball's trajectory time from table to the floor to be 0.34 s. What is the height of the table? (g = 9.8 m/s2 and air resistance is negligible)

*June 10, 2010*

**algebra**

okay I understand thanks!

*June 8, 2010*

**algebra**

Ms. Sue how did you get -8? is this the common number?

*June 8, 2010*

**algebra**

first you would need to find the value of x I divided -720 by 9 and got -80 however this is not correct so I tried -90 and it proved to be true. So x = -90 I also would like to know what a simpler way of solving this problem would be?

*June 8, 2010*

**Algebra**

What similarities and differences are there between functions and linear equations?

*June 8, 2010*

**Math**

1. You would need to multiply the total check by 15%. 2. Assuming your commission rate is that of the clients payment... you would do the same as the first question... multiply.

*June 8, 2010*

**math**

32 times

*June 7, 2010*

**chemistry**

What is the standard heat of reaction (Delta H^0) for the decomposition of hydrogen peroxide? 2H2O2 (l) ==> 2H2O (l) + O2(g)

*May 23, 2010*

**Chemistry**

What is the standard heat of reaction (Delta H^0) for the decomposition of hydrogen peroxide? 2H2O2 (l) ==> 2H2O (l) + O2(g)

*May 23, 2010*

**physics**

An elevator cab in the New York Marriott Marquis has a mass of 4.96 x 103 kg and can carry a maximum load of 1.80 x 103 kg. If the cab is moving upward at full load at 3.71 m/s, what power is required of the force moving the cab to maintain that speed?

*May 21, 2010*

**physics**

A 0.077-kg arrow is fired horizontally. The bowstring exerts an average force of 50 N on the arrow over a distance of 0.75 m. With what speed does the arrow leave the bow?

*May 21, 2010*

**Chemistry**

Using calories, calculate how much heat 32.0g of water absorbs when it is heated from 25.0 degrees C to 80.0 degrees C. How many joules is this? Are these steps right? 32.0g x 55*C = 1760 calories = 420.65 Joules

*May 19, 2010*

**Chemistry**

Using calories, calculate how much heat 32.0g of water absorbs when it is heated from 25.0 degrees C to 80.0 degrees C. How many joules is this?

*May 19, 2010*

**Chemistry**

What Rght said

*May 19, 2010*

**Chemistry**

Using calories, calculate how much heat 32.0g of water absorbs when it is heated from 25.0 degrees C to 80.0 degrees C. How many joules is this?

*May 19, 2010*

**computers**

Microsoft Excel (full name Microsoft Office Excel) is a spreadsheet application written and distributed by Microsoft for Microsoft Windows and Mac OS X. It features calculation, graphing tools, pivot tables and a macro programming language called VBA (Visual Basic for ...

*May 18, 2010*

**Chemistry**

But that's just .100 over .100 for the base over acid isn't it? then it would just be 6.4 X 10-5 because the log of 1 is 0?

*May 5, 2010*

**Trig**

The answer is -128+128i

*May 4, 2010*

**algebra**

the sum of

*May 3, 2010*

**Chemistry**

Which of the following compounds will melt ice at the lowest temperature? Sucrose, sodium chloride, or magnesium chloride?

*May 2, 2010*

**Chemistry**

Answer the following question about copper (II) sulfate pentahydrate: a)how much water (in g) is there in 10.0 g of the compound listed above? b)If you needed 2.50g of CuSO4 for a reaction but only had CuSO4 * 5H2O available, how many g would you need to use to get the same ...

*May 2, 2010*

**Chemistry**

A)250 g of LiBr is dissolved in 200g of water 100 degrees C. The solution is then cooled to 20 degrees C. How much precipitate (if any) is formed? B) 42 g of KCl is dissolved in 100g of water at 50 degrees C. The solution is then cooled to 20 degrees C. How much precipitate (...

*May 2, 2010*

**Global History**

What were the differing politucal and economic systems between the US and Soviet Union that helped lead to the Cold War? I know that the political difference was that the US was democratic and the Soviet Union were communists. However, if the US economic system was ...

*May 1, 2010*

**chemistry**

What is the freezing point of each solution? a)1.40mol Na2SO4 in 1750 g H2O Are these the right steps? 1.40mol Na2SO4 / 1.75kg = .8m 3 * 1.86 degrees C * .8m = 4.46 degrees C 4.46 degrees C - 1.86 degrees C = 2.6 degrees C

*April 29, 2010*

**Chemistry**

Determine the freezing points of each 0.20m aqueous solution. a)K2SO4 b)CsNO3 c)Al(NO3)3

*April 29, 2010*

**Chemistry**

What is the freezing point of each solution? a)1.40mol Na2SO4 in 1750 g H2O b)0.060 mol MgSO4 in 100g H2O

*April 29, 2010*

**math algebra with pizzazz**

pg 142 What happened to the computer programer

*April 28, 2010*

**Chemistry**

How many grams of K2SO4 would you need to prepare 1500 g of 5.0% K2SO4 (m/m) solution?

*April 26, 2010*

**Kindergarten Math**

A counter is a small plastic circle about a half-inch in diamiter

*April 19, 2010*

**grade 10 career studies**

I have to hand in an assignment called WHO AM I? for my grade 10 career studies course, i just need to no what to hand in exactly

*April 16, 2010*

**Osciallations**

A harmonic oscillator has mass 0.530km and an ideal spring with force constant 146N/m . Find the period, frequency, and angular frequency.

*April 15, 2010*

**Trig**

oh it's tan(x/2) = a ........... use the fact that x = 2 . x/2

*April 13, 2010*

**Trig**

Given that tan(pi/2) = a. Express tan(x) and sin(x) in terms of a. Hint: Use the fact that x = 2.(pi/2)

*April 13, 2010*

**Chemistry**

Which of the following substances dissolve to a significant extent in water? Explain your answer in terms of polarity. a) CH4 b) KCL c)He d)MgSO4 e)sucrose f)NaHCO3

*April 13, 2010*

**PRE CAL SEQUENCES**

Given the following finite sum 1/(1*2)+1/(2*3)+1/(3*4)+1/(4*5)+....+1/(n(n+1)) a) Find the first 5 partial sums b) Make a conjecture for a formula for the sum of the first n terms c) Use mathematical induction to prove your formula

*April 12, 2010*

**Accounting**

The cost principle requires that when assets are acquired, they be recorded at

*April 12, 2010*

**Chemistry**

The molecules water (H2O) and methane (CH4) have similar masses, but methane changes from a gas to liquid at -161 degrees C. Water becomes a gas at 100 degrees C. what could account for the difference?

*April 11, 2010*

**math**

4(9.75h-3)=150 39h-12=150 39h=162 h=162/ 39=4.15, which means they can Afford to rent for 4 hours. This is for part (A)

*April 7, 2010*

**English**

the answer is do it yourself and stop trying to get it without studying you lazy ass.

*April 7, 2010*

**Social Studies**

What happened to Andrew Jackson when he was eight years old?

*April 6, 2010*

**Chemistry**

In a reaction chamber, 3.0mol of aluminum is mixed with 5.3mol Cl2 and reacts. The reaction is described by the following balanced chemical equation. 2Al + 3Cl2 ==> 2AlCl3 a)Identify the limiting reagent for the reaction. b)Calculate the number of moles or products formed c...

*April 5, 2010*

**Web application development JSP**

I would suggest that you go to a programming forum and ask for assistance there. I'm sure you will have more luck. Considering most helpers here are not proficient in programming. Good Luck!

*April 1, 2010*

**Physics**

A particle is moving along the x-axis subject to the potential energy function U(x) = 1/ x + x2 + x – 1. Determine the x-component of the net force on the particle at the coordinate x = 3.57 m

*March 31, 2010*

**chemistry**

If 7.24 kJ of heat is applied to a 952 g block of metal, the temperature increases by 10.7 degrees Celsius. Calculate the specific heat capacity of the metal in J/g degrees Celsius.

*March 29, 2010*

**Chemistry**

Write the 12 mole ratios that can be derived from the equations for the combustion of isopropyl alcohol. 2 C3H7OH(l) + 9 O2(g) ==> 6 CO2(g) + 8 H2O (g)

*March 22, 2010*

**Physics**

img242.imageshack.us/img242/9452/words.jpg That should be the image.

*March 21, 2010*

**Physics**

Hi, I've been having issues with solving this problem. Could anyone help? Two blocks, of masses M = 2.0 kg and 2M are connected to a spring of spring constant k = 215 N/m that has one end fixed, as shown in the figure below. The horizontal surface and the pulley are ...

*March 21, 2010*

**Chemistry**

Is 2HCl soluble in water? Is BaSO4 soluble in water?

*March 16, 2010*

**Chemistry**

Identify the precipitate formed when solutions of these compounds are mixed. H2SO4 + BaCl2 ==> So when you do the double replacement reaction, would the products of this chemical equation be HCl + BaSO4? or H2Cl2 + BaSO4 ? (not balanced) also would both of the products be ...

*March 16, 2010*

**Chemistry**

How do you balance Al(OH)3 --> Al2O3 + H2O Why does the OH decompose into O3 and H2O??

*March 15, 2010*

**Chemistry**

Classify each reaction and balance the equations. Al(OH)3 ==> Al2O3 + H2O

*March 15, 2010*

**Chemistry**

Complete and balance this decomposition reaction HI ==> is this reaction HI ==> H + I ? or... HI ==> H2 + I2 ? why?

*March 14, 2010*

**Chemistry**

Complete and balance this equation for a combination reaction. Be + O2 ==> Would it be Be + O2 ==> BeO2 ? or... 2Be + O2 ==> 2BeO ? Why??

*March 14, 2010*

**science**

okay after the diver jumps foward from the diving board,the force of gravity will accelerate the diver PARALLEL to the direction of motion , is the uppercase true or false?

*March 8, 2010*

**Physics**

An electric field exerts a force of 3.00 E-4 N on a positive test charge of 7.20 E-4 C. The magnitude of the field at the location of the charge is?

*March 7, 2010*

**Math**

sweet, thanks for the help guys, gonna win now.

*March 6, 2010*

**Chemistry**

Solid aluminum carbonate decomposes to form solid aluminum oxide and carbon dioxide gas. Is Al2(CO3)3 ==> Al2O3 + CO2 the right equation? If so, how do you balance this equation?

*March 1, 2010*

**Chemistry**

Balance the following equations. A) SO2 + O2 --> SO3 B)Fe2O3 + H2 --> Fe +H2O C)P + O2 -->P4O10 D)Al + N2 --> AlN

*February 28, 2010*

**Chemistry**

Write and balance equations for the following reactions. A)Iron metal and Chlorine gas react to form solid iron(III) chloride. B)Solid aluminum carbonate decomposes to form solid aluminum oxide and carbon dioxide gas. C)Solid magnesium reacts with aqueous silver nitrate to ...

*February 28, 2010*

**chemistry**

Write Skeleton equations for these reactions. A) Heating Copper(II) sulfide in the Presence of diatomic oxygen produces pure copper and sulfur dioxide gas. B)When heated, baking soda (Sodium hydrogen carbonate) decomposes to form the products sodium carbonate, carbon dioxide, ...

*February 28, 2010*

**bcc**

if you put honey,water,dishwashing liquid and vegetable oil in a clear jar and then you add asmall of plastic cup, plastic fork, straw and a small piece of styrofoam cup.

*February 26, 2010*

**bcc**

how do you work equation dealing friction and newtons when pulling the distance of a block

*February 26, 2010*

**Music**

tell me about the rocks band

*February 26, 2010*

**Chemistry**

which has the highest lattice energy BaO or SrO

*February 23, 2010*

**chemistry**

Compound A contains 1.75g nitrogen and 3.99g oxygen. Compound B contains 19.6g nitrogen and 56.0g oxygen. Are compounds A and B the same? Explain.

*February 21, 2010*

**chemistry**

Find the molar mass of Chromium (III) Hydrogen Phosphate. Also, what is the chemical formula for this molecule?

*February 21, 2010*

**chemistry**

The mass of twenty-three dozen pencils is 1.496 kg. What is the mass of 1 pencil?

*February 21, 2010*

**chemistry**

How many neon atoms are there in five moles?

*February 21, 2010*

**chemistry**

How many carbon atoms are there in 150.0 g Glucose? (Glucose is C6H12O6, molar mass = 180.16 g/mol)

*February 20, 2010*

**chemistry**

Convert 12 fluid ounces liters. (1 fl. oz = 29.57 cm^3)

*February 20, 2010*

**chemistry**

Which of the following are empirical formulas? A) Ribose (C5H10O5) B) Ethyl Butyrate (C6H12O2) C) Chlorophyll (C55H72MgN4O5) D) DEET (C12H17ON) (numbers are subscripts)

*February 17, 2010*

**ecology**

examples of how humans have increased their food supply and what effects these methods have on the environment overall.

*February 16, 2010*

**chemistry**

How many grams of oxygen are there in 100.0 grams of water? What percentage of the mass of water is oxygen?

*February 15, 2010*

**chemistry**

Find the number of K atoms, C atoms, and O atoms in 95.5g of K2Cr2O7. (Potassium 2, Chromium 2, Oxygen 7).

*February 15, 2010*