Wednesday

October 22, 2014

October 22, 2014

Total # Posts: 971

**AP Chemistry**

What is the equation for the standard enthalpy of formation for magnesium nitrate?
*November 14, 2010*

**Physics **

The answer is wrong. What did u get?
*November 13, 2010*

**Physics **

A 2.30 102 N force is pulling an 80.0 kg refrigerator across a horizontal surface. The force acts at an angle of 21.0° above the surface. The coefficient of kinetic friction is 0.200, and the refrigerator moves a distance of 7.00 m. (a) Find the work done by the pulling ...
*November 13, 2010*

**chemistry**

which of the following would form acidic,basic or neutral solutions:nh4f,nh4cn,nh4ch3coo,nh4cl,ba(ch3coo)2,nacn,caso4,cr(no3)3,fecl3,na2co3
*November 11, 2010*

**Physics**

2. A person exerts a perpendicular force of 75 N on a door. Calculate the torque on the door hinges if the force is applied a distance of 30 cm, 50 cm, and 75 cm from the hinge.
*November 4, 2010*

**American Government**

Haha never thought of it that way! Thanks!
*November 4, 2010*

**American Government**

Is this statement true: The Secretary of Defense could never become President.
*November 4, 2010*

**Integrated math**

A meteorologist tracked the increase and decrease of rain totals in inches from the previous year. This is the data for the following 4 months: January -1.34, February +2.68, March + 1.79, April -0.87. Estimate the change from the previous year by adding the totals rounded to...
*November 3, 2010*

**CHEM. help please**

2 H2O (l) → 2 H2 (g) + O2 (g) 1. Without doing any calculations, which side will enthalpy favor in this reaction? Entropy? 2. What volume of water in gallons would need to be split to store the same amount of energy as found in 10.0 gallons of gasoline? (Gasoline ...
*November 2, 2010*

**chem**

In a vehicle, H2 could be used in a fuel cell to generate energy. Hydrogen is not an energy source, but a means of transporting energy because the extraction of H2 from the logical source, H2O, takes as much energy as is returned when the gas is used. 2 H2O (l) → 2 H2 (g...
*November 2, 2010*

**physics**

an object is initially moving 15.0 m/s. a minute later, it is moving 25.0 m/s in the opposite direction. What is the displacement and acceleration?
*October 31, 2010*

**Math Help Please**

x=4.4
*October 28, 2010*

**chem 101**

using the unit conversion method derive an equation to calculate heat produced from the HCl-Na OH reaction
*October 26, 2010*

**6th grade**

What are the two similar features for long shore current and rip currents?
*October 26, 2010*

**chem 101**

how many grams of oxalic acid dihydrate to completely neutralize 25ml of 0.12 M of sodium hydroxide
*October 18, 2010*

**physics**

the string off of A
*October 8, 2010*

**physics**

no its on a flat surface with the static friction of .25. and W is hanging off the string at a 45 degree angle vertically.
*October 8, 2010*

**physics**

(a)block A weigh 60N. the coefficient of static friction between the block and the surface on which it rests is 0.25. the weight W is 12N and the system is at equilibrium. find the friction force exerted on block A. (b)find the maximum weight W for which the system will remain...
*October 8, 2010*

**us history**

Since the Constitution has been ratified, how many states have been admitted to the union?
*October 8, 2010*

**physics**

An elevator and its load have a combined mass of 1700 kg. Find the tension in the supporting cable when the elevator, originally moving downward at 13 m/s, is brought to rest with constant acceleration in a distance of 43 m.
*October 7, 2010*

**physics**

i have plugged in all the numbers and got .51 what do i do at this point???
*October 5, 2010*

**physics**

A block is hung by a string from the inside roof of a van. When the van goes straight ahead at a speed of 26 m/s, the block hangs vertically down. But when the van maintains this same speed around an unbanked curve (radius = 135 m), the block swings toward the outside of the ...
*October 5, 2010*

**PHYSICS**

thanks for the detailed explanation
*October 5, 2010*

**chemistry**

HBr is a molecular substance that is a strong acid in water. Write an equation for its ionization in water. Use minimal integer numbers to balance the reaction. Include physical states in your answer, e.g., start with HBr(l).
*October 4, 2010*

**Chemistry**

0.01L KHP * 0.445M KHP = 0.00445 molKHP KHP and NaOH are in 1 to 1 ratio so, moles NaOH = 0.00445 so, 0.00445mol NaOH/ 0.01154L NaOH = 0.386M NaOH
*October 4, 2010*

**Physics**

Ok thanks.
*October 4, 2010*

**Physics**

A bicycle wheel that initially spins at 3 revolutions per second is braked uniformly to a stop in 1 second. A spot is painted at the outer edge of the wheel. How many revolutions does the spot go during the time it takes the wheel to stop? The answer I got was 0.5 but was ...
*October 4, 2010*

**math**

What is the naming convention for a vector when two arrow point outward from a central point?
*September 21, 2010*

**PHYSICS**

F=Ma M =79kg a= 9.8ms^-2 (gravity) There is no other acceleration component since the aeroplane is at constant velocity so Force on pilot is... 79 x 9.8 = 774.2 N
*September 21, 2010*

**Algebra**

Sorry didn't see your second answer, great thanks a lot.
*September 17, 2010*

**Algebra**

I understand, your answer never mind. Thanks :)
*September 17, 2010*

**Algebra**

sorry don't understand
*September 17, 2010*

**Algebra**

100^0 one hundred to the zero power, would it be zero or one hundred?
*September 17, 2010*

**math**

32.5 - 45.8 please show steps!
*September 17, 2010*

**math**

x/7+5=10
*September 17, 2010*

**physics**

The left ventricle of the heart accelerates blood from rest to a velocity of +26 cm/s. (a) If the displacement of the blood during the acceleration is +1.9 cm, determine its acceleration (in cm/s2). (b) How much time does it take for the blood to reach its final velocity?
*September 9, 2010*

**physics**

The left ventricle of the heart accelerates blood from rest to a velocity of +23 cm/s. (a) If the displacement of the blood during the acceleration is +2.1 cm, determine its acceleration (in cm/s2). (b) How much time does blood take to reach its final velocity? in seconds
*September 7, 2010*

**physics**

A jetliner, traveling northward, is landing with a speed of 65 m/s. Once the jet touches down, it has 785 m of runway in which to reduce its speed to 5.0 m/s. Compute the average acceleration (magnitude and direction) of the plane during landing (take the positive direction to...
*September 7, 2010*

**algebra**

look at the algebraic equation that u posted previously. try to form an equation similar to that.
*September 5, 2010*

**algebra 1**

1. find a common multiple for the denominators of both fractions. 2. combine the fractions together. do not expand the numerator first. 3. cross multiply. 4. expand the terms 5. make x the subject. 6. solve.
*September 5, 2010*

**Physics - Circular motion**

A marble of mass m is placed on top of a bowling ball of radius r and allowed to roll from rest. derive the angle from centre of circle at which the marble loses contact with bowling ball. assume there is no friction between marble and bowling ball.
*September 5, 2010*

**3rd grade**

I am a number greater than 99 and less than 1,000. Two of my digits that aren't next to each other are the same. My tens digit could not be greater and it is 1 more than my hundreds digit. What number am I?
*August 30, 2010*

**conversion problems**

I don' know ask google
*August 25, 2010*

**Math**

What if the height of the water is only 15 cm, half the height of the hemisphere?
*August 19, 2010*

**Physics (Static Friction)**

divide by a 1000 your original answer is in N i believe also i would like to know how you solved this
*July 28, 2010*

**British Literature**

1. a 2. d 3. c 4. b 5. a 6. b 7. d 8. a 9. c i don't feel like doing any more. stop being so lazy
*July 21, 2010*

**MATHS**

to get the average do i add them all up and divide by the number of obsevations? say maths 646 divided by 14 = 46.1428 science 598 divided by 14 = 42.714 thanks
*July 19, 2010*

**MATHS**

oops sorry forgot the rest of the info: 14 students and their scores: MATHS 28 35 37 50 69 84 40 65 29 42 51 45 31 40 science 45 39 39 61 64 88 31 55 57 45 71 73 33 52 these are a random sample...... so if the kid gets 58 in maths how do you work out what his prdicted score ...
*July 19, 2010*

**MATHS**

if a student scores 58 in a maths exam predict the score they would get in science??? Have no idea where to start on this answer other than having a good guess!! Can anyone help please??? Thanks Andrew
*July 19, 2010*

**Math**

What is 34920421-98349238
*July 14, 2010*

**FINANCE**

1 million bottles at $1 a bottle is $1 million minus 50 cents a bottle is $500,000 minus $200,000 fixed costs per year is $300,000 minus $150,000 in taxes is $150,000 left plus 10% per year from the bank is $165,000 times 5 years is $825,000 made. I would do it.
*July 14, 2010*

**math **

Factor the expression: x to the 2nd power+3x+2?
*July 13, 2010*

**chemistry**

124 atm
*July 7, 2010*

**Chem**

f the molecular mass for a chemical is 352.04 g/mol and the enthalpy of formation is -2137 kJ/mol, the heat change will be ______ kJ when 10.0 g of this chemical is formed.
*May 17, 2010*

**Chem**

f the molecular mass for a chemical is 352.04 g/mol and the enthalpy of formation is -2137 kJ/mol, the heat change will be kJ when 10.0 g of this chemical is formed.
*May 17, 2010*

**Math**

Square Root of 5 plus 2 Square root of 2 over 4 minus the square root of 5 simplify
*May 12, 2010*

**8th grade social studies**

which of the followin is a power of the president???
*May 10, 2010*

**algebra 2**

What is the Domain and Range of the Radical Parent function
*May 8, 2010*

**algebra 2**

What is the Domain and Range of the Radical Parent function
*May 8, 2010*

**Technology**

I'm writing an essay, and the first page is a cover page. Obviously, there shouldn't be a number there. How do I get rid of it so that there's still numbers on the other pages?
*May 4, 2010*

**Chemistry**

Is it possible to determine the Ka of a weak acid at points other than the halfway point of a titration? Explain.
*May 3, 2010*

**Chemistry**

Find the pH experimentaly .1 ml before and .1 ml after the equivalence point if the experimental equivalence point was found to be at 35 ml. In this titration, you are titrating 0.500 M NaOH with 0.250 M HCl.
*May 2, 2010*

**Chemistry**

How do you solve for the experimental pKa when doing a titration?
*May 2, 2010*

**Chemistry**

If you have 0.100 M Pyridine titrated with 0.100 M HCl, choose an appropriate indicator and explain?
*May 2, 2010*

**Algebra 2**

Find the solution of the exponential form in terms of logarithms 2^(2x+13) = 3^(x-45)
*April 30, 2010*

**Math**

find the solution of the expontetial equation 1+7^(5x)=19
*April 30, 2010*

**English**

We were eating apples, bananas, and watermelon on Tuesday.
*April 29, 2010*

**Geography**

I was wondering if a plane flew west and kept flying, would it be possible for it to never fly into night if it didn't stop?
*April 19, 2010*

**english**

how do sonnets compare with modern day music and songs? its for a presentation
*April 16, 2010*

**Biology**

aerobic respiration?
*April 7, 2010*

**Chemistry**

If there were two solutions- one with areagent(100% pure) mixed in water and the other solution containing the same reagent (99.9% pure) mixed in equal volume of water. How significant would the difference in concentration be between these two solutions?
*March 29, 2010*

**Physics**

Hey I'm lost on this physics problem can anyone tell me which equations i'm suppose to use in these questions a) A skier inhales a breath of air at Temp-air = 3.9 ¢XC and exhales it as Volume-air = 1.92 liters of air at Temp-body = 37 ¢XC and atmospheric ...
*March 27, 2010*

**CHEMISTRY **

WHAT FACTORS ARE CONSIDERED TO BE STRESSES ON AN EQUILIBRIUM SYSTEM
*March 26, 2010*

**Physics**

1a. Two converging lenses, each of focal length 14.4 cm, are placed 60.6 cm apart, and an object is placed 26.9 cm in front of the first. Where is the final image relative to the second lens formed? b. What is the magnification of the system?
*March 23, 2010*

**Math**

What rate would it take to double an object valued currently at $100 in 6 years? I would like to know the answer and the equation/steps taken to solve the problem.
*March 23, 2010*

**Nutrition**

Why do sucrose-fed rats (high carb diet) consume less rat chow (protein, fat, fiber) than the control rats?
*March 21, 2010*

**Chemistry**

Determine the volume of a 0.550 M KMnO4 solution required to completely react with 2.55 g of Zn.
*March 19, 2010*

**7th grade**

37.5
*March 18, 2010*

**math**

What is the probability that exactly three children in a family of five children will be boys? Assume that P(boy)=P(girl)
*March 9, 2010*

**Volume of a rectangular prism**

Thanks. Therefore, the answer is 512. 2 x 16 x 2 = 64 4 x 32 x 4 = 512 Appreciate your help, Andrew
*March 1, 2010*

**Volume of a rectangular prism**

Hello, if the volume of a rectangular prism is LWH = 64 cubic inches, what are the dimensions of a rectangular prism with dimensions twice as long? Thank you!
*March 1, 2010*

**science**

Explain the similarities and differences of the multicellular stages of acellular and cellular slime molds.?
*February 27, 2010*

**MATH**

f(x)= 3x+9/(x^2-100) If this function has a horizontal asymptote, give its y-value Find the x-intercept(s). Find the y-intercept
*February 24, 2010*

**ENGLISH**

CAN SOMEONE HELP ME WITH WRITING AN EPIC POEM ABOUT A HERO? MY ASSIGNMENT IS DUE MAR. 1. IT HAS TO BE 4 PAGES LONG.
*February 24, 2010*

**Physics**

Suppose the coefficient of static friction between the road and the tires on a car is 0.60 and the car has no negative lift. What speed will put the car on the verge of sliding as it rounds a level curve of 29.3 m radius?
*February 18, 2010*

**Physics**

What is the smallest radius of an unbanked (flat) track around which a bicyclist can travel if her speed is 35 km/h and the μs between tires and track is 0.35?
*February 18, 2010*

**chemistry**

You are asked to prepare 150.0 mL of 3.15×10−2 M AgNO3. 2.) An aqueous solution is 6.40% methanol CH3OH by mass, with d = 0.988 g/mL} What is the molarity of CH3OHOH} in this solution?
*February 16, 2010*

**chemistry**

thank you
*February 16, 2010*

**chemistry**

1.)How many grams would you need of a sample known to be 99.81% AgN03 by mass? You are asked to prepare 150.0 mL of 3.15×10−2 M AgNO3. 2.) An aqueous solution is 6.40% methanol CH3OH by mass, with d = 0.988 g/mL} What is the molarity of CH3OHOH} in this solution?
*February 16, 2010*

**chemistry**

1.)How many grams would you need of a sample known to be 99.81% AgN03 by mass? You are asked to prepare 150.0 mL of 3.15×10−2 M AgNO3. 2.) An aqueous solution is 6.40% methanol CH3OH by mass, with d = 0.988 g/mL} What is the molarity of CH3OHOH} in this solution?
*February 16, 2010*

**chemistry**

2.) How much heat must be absorbed at 1357 K to melt a bar of copper (80 * 10 * 12 cm) assume d = 8.93 g/cm^3. The normal boiling point is 1357 K, and heat of fusion is 13.05 KJ/mol.
*February 15, 2010*

**chemistry**

How much heat, in kilojoules, is evolved when a 3.70 kg sample of molten Cu freezes? The normal boiling point is 1357 K, and heat of fusion is 13.05 KJ/mol. 2.) How much heat must be absorbed at 1357 K to melt a bar of copper (80 * 10 * 12 cm) assume d = 8.93 g/cm^3.
*February 15, 2010*

**chemistry**

How much heat, in kilojoules, is evolved when a 3.70 kg sample of molten Cu freezes? The normal boiling point is 1357 K, and heat of fusion is 13.05 KJ/mol. 2.) How much heat must be absorbed at 1357 K to melt a bar of copper (80 * 10 * 12 cm) assume d = 8.93 g/cm^3.
*February 15, 2010*

**AP Chemistry**

The combustion of 1.00 mol of sucrose,C12H22,O11, evolves 5650 kJ of heat. A bomb calorimeter has a calibrated heat capacity of 1.23 kj/degree Celsius. How many grams of sucrose should be burned to raise the temperature of the calorimeter and its contents from 23 degrees C to ...
*February 15, 2010*

**Philosophy**

What fallacies, if any, are present in the following passage? Can you please give reasons for your answer, that is, if you say that a fallacy has been committed, then show where the fallacy occurred, and explain why you think it is a fallacy? The following is the paragraph. ...
*February 12, 2010*

**Physics (2)**

Consider a charged ring of radius 43.4 cm and total charge 18 nC. We are interested in the electric field a perpendicular distance z away from the center of the ring. At what distance from the center of the ring does the electric field become maximum ..so E=kQ/(x^2)at a ...
*February 11, 2010*

**Physics**

Consider a charged ring of radius 43.4 cm and total charge 18 nC. We are interested in the electric field a perpendicular distance z away from the center of the ring. At what distance from the center of the ring does the electric field become maximum?
*February 11, 2010*

**Calculus**

how did you get the 8cm?
*January 31, 2010*

**Social Studies**

One of the biggest reasons for the increased European agricultural production in the medieval period was? A) the introduction of a heavier plow. B) the official support of the serfs by the popes. C) the introduction of new crops from the Byzantine world. D) the money invested ...
*January 25, 2010*

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