Monday
October 20, 2014

Posts by Jack


Total # Posts: 1,335

Chemistry
Quicklime (CaO) can be prepared by roasting limestone (CaCO3) according to the reaction CaCO3(s)  −!CaO(s) + CO2(g) . When 2.6 ×10^3 g of CaCO3 are heated, the actual yield of CaO is 1.06 ×10^3 g. What is the percent yield? Answer in units of %.
March 23, 2011

Chemistry
When 2.6 ×103 g of CaCO3 are heated, the actual yield of CaO is 1.06 ×103 g. What is the percent yield? Answer in units of %.
March 23, 2011

math
There are about 3400 species that represent 90 percent in the world what is the total number.
March 16, 2011

chemistry
why does a solution of ammonium acetate has a pH=7.5
March 16, 2011

calculus
y=x^3 y=8 x=0 about x-axis its using shell method i need step by step help seriously !!!!
March 14, 2011

operating system
How do you change a word in the header. Then close Header/Footer when done?
March 7, 2011

earth
Was there any magnetic pulling during the Mesozoic Era?
February 28, 2011

Algebra
How many different points of intersection are there for x + y = 7 and y = x squared minus 7?
February 27, 2011

math
derivative of ln(x^3 + 2)
February 23, 2011

Physics
If the angle of incidence is 30 degrees, what is the angle of reflection?
February 21, 2011

Intermediate Algebra
Solve using the elimination method. Show your work. If the system has no solution or an infinite number of solutions, state this. 10x + 7y = -120.5 -20x – 14y = 241
February 20, 2011

College Algebra
Solve using the elimination method. Show your work. If the system has no solution or an infinite number of solutions, state this. <P-3x + 6y = -3 -6x + 4y = -10
February 20, 2011

algebra
To buy both a new car and a new house, Tina sought two loans totalling $260,394. The simple interest rate on the first loan was 3.7%, while the simple interest rate on the second loan was 8.8%. At the end of the first year, Tina paid a combined interest payment of $22,611.73. ...
February 20, 2011

intermediate algebra
Determine whether the point (0, 8) is a solution of the system -3x + 9y = 72 / 9x + 3y = 24
February 19, 2011

intermediat algebra
. Solve using the elimination method. Show your work. If the system has no solution or an infinite number of solutions, state this. -2x + 9y = 56 9x – 9y = 0
February 19, 2011

Physics
If two electrons (q = 1.60 x 10–19 C) are 1 m apart, what is the magnitude of the electric force repelling the two electrons?
February 18, 2011

English
1.Weren't you ______ to help me wash the dishes? (suppose) I have use correct form of suppose. Would it be suppose?
February 15, 2011

English
Thanks. Have a good night.
February 14, 2011

English
Using the correct form of (eat, ate, sit, set) 1.Someone (eat) all the leftover sandwiches. 2.Thank you, but I have already (ate, eaten) lunch. 3.After splitting the logs, the farmer (sat, set) his ax on the ground. 1.ate 2.eaten 3.set
February 14, 2011

English
1.We (see) tropical fish in the warm waters surrounding the island. 2.Have you (speak) to your parents about the field trip? 3.Teresa has (choose) the smallest piece of chicken. 4.Yesterday someone on the radio (sing) a song about Brazil. Just seeing if I have hang of it now. ...
February 14, 2011

English
1.dreamt 2.drank 3.sunk 4.taken 5.frozen 6.grown
February 14, 2011

English
Do you have another website to help me? I'm still confused. I looked over list.
February 14, 2011

English
1.I have often (dream) of becoming a great writer. 2.I (drink) two glasses of orange juice at breakfast today. 3.Their new boat (sink) in six feet water. 4.Generation have (take) wood and food from the rain forests. 5.The canal has (freeze), and the ferry can't get through...
February 14, 2011

science
if you weigh 100 pounds on earth than how much would you weigh on each other planet in our solar system
February 14, 2011

math
x^2 + y^2 - 8x -2y -3 = 0 the points S and T lie on the circumference of the circle. M is the midpoint of the chord ST. Length of Centre C to M is 2. whats the length of ST??
February 13, 2011

Physics
Nick, I'm working on this one myself. You can deduce from V = sqrt (T/M) where M=mass/length that f*2L = sqrt (T/M) but I keep getting the wrong answer for L. Unit conversion maybe?
February 10, 2011

business math
Stereo Inc. sells a stereo system for $300 down and monthly payments of $80 for the next 3 years. If the interest rate is 3.25 % per month, what is the cost of the stereo?
February 9, 2011

math
x=-2 output=12 x=1 output =9 x=4 output =6 help me solve
February 9, 2011

math
x=-2 output=12 x=1 output =9 x=4 output =6 help me solve
February 9, 2011

math
x=-2 output=12 x=1 output =9 x=4 output =6 help me solve
February 9, 2011

chemistry
how do you Prepare a 0.1 L of a 0.1 M NaCl solution, and describe the process in writing.
February 9, 2011

chemistry
how do you Prepare a 0.1 L of a 0.1 M NaCl solution, and describe the process in writing.
February 9, 2011

New Age Math
A value of the number m for which there is either no solution or an infinite number of solutions (u,w) to the system of equations shown below is: 6⁢u-w=6 m⁢u+6⁢w=-2
February 5, 2011

New Age Math
Given the initial augmented matrix -1 1 2 0 2 -1 -3 0 2 -2 -4 0 find the RREF
February 5, 2011

physics
change in momentum: p = m*(change in velocity) p = 91.8367 kg * (2 m/s) = 183.673 kg*m/s
February 3, 2011

physics
F = m*a 900N = m*(9.8m/s^2) m = 91.8367 kg a = (change in velocity) / (change in time) a = (Vf - Vi) / (change in time) a = (2 - 0) / (.7) = 2.85714 m/s^2 F = 91.8367 kg * 2.8571 m/s^2 = 262.391 N
February 3, 2011

physics
the mass you use is not 60g, it is .06kg. Sorry. Answer is .00015 sec.
February 3, 2011

physics
f=m*a 30000N = 60g * a a = (change in velocity) / (change in time) 30000N = 60g * (Vf - Vi) / (change in time) 500 = (75 - 0) / (change in time) change in time = .15 sec the change in time is the time that the ball was in contact with the club
February 3, 2011

physical chemistry
i think i figured it out
February 3, 2011

physical chemistry
1 kg aluminum dumbbell initially held 2 meters above the floor is allowed to fall. This experiment is performed inside a room whose dimensions are 10m × 5m × 3m. Assuming that the walls of the room do not conduct heat and that the room is empty (no other objects ...
February 3, 2011

Chemistry
How do I balance this equation and what is the answer? C3H9N+O2-->CO2+H2O+NO2
February 2, 2011

Chemistry
How much ice is required to cool a 15.0 oz drink from 71 F to 34F, if the heat capacity of the drink is 4.18 J/g*C? (Assume that the heat transfer is 100 % efficient.)
February 1, 2011

english
What is 7 letter word for finished. 3rd letter is R and 5th letter is U
February 1, 2011

physics
Modern lasers can create a pulse of light that lasts only a few femtoseconds. (a) What is the length of a pulse of red light that lasts 6.2 fs? (b) How many wavelengths of red light (ë = 680 nm) are included in such a pulse?
January 30, 2011

physics
Modern lasers can create a pulse of light that lasts only a few femtoseconds. (a) What is the length of a pulse of red light that lasts 6.2 fs? (b) How many wavelengths of red light (ë = 680 nm) are included in such a pulse?
January 30, 2011

operating system
in windows vista, how do you organize file list by file size?
January 30, 2011

chemistry
V=359L
January 27, 2011

chemistry
What volume does a mixture of 14.2g of helium and 21.6g of hydrogen gas occupy at 28 degrees celcius and .985atm?
January 27, 2011

5th grade math
my bad it is 2/5 not 3/5
January 27, 2011

5th grade math
3/5 change the denominator to 15 by multiplying by 3 so it is 9/15-3/15=6/15 if you reduce it is 3/5
January 27, 2011

Spanish
22. C 23 a
January 27, 2011

Math help once again
10^y=x so 10^10=x
January 27, 2011

chemistry
thanks i solved it already
January 27, 2011

chemistry
Ammonia reacts with oxygen gas to form nitrogen monoxide and water. At constant temperture and pressure, how many of nitrogen monoxide can be made by the reaction of 800. ml of oxygen gas?
January 27, 2011

Spanish
it is asking if you have to have your lobster cooked with butter
January 27, 2011

Math
If line f is parallel to the line h, and line f has y-intercept 5, what is the equation of line f ? With h passing through two points (1, 2) and (3, 6)
January 25, 2011

CHM
Assuming the density of acetic acid solution is 1.0 g/mL, determine the volume of the acetic acid solution necessary to neutralize 25.0 mL of 0.10 M NaOH. Record this calculation on your report sheet
January 25, 2011

Math
If line g passes through point (2, 2) and is perpendicular to the line h, then what is the equation of line g? With h passing through two points (1, 2) and (3, 6)
January 25, 2011

Math
If line f is parallel to the line h, and line f has y-intercept 5, what is the equation of line f ? With h passing through two points (1, 2) and (3, 6)
January 25, 2011

Math
If line f is parallel to the line h, and line f has y-intercept 5, what is the equation of line f ? With h passing h through two points (1, 2) and (3, 6)
January 25, 2011

algebra
a rectangular sheet of plywood is seven times longer than its width,write an simlify an expression for the perimeter of the rectangle in terms of the width.
January 24, 2011

linear algebra
show that if L is any line through the origin in R3 and x is any vector with its initial point at the origin, then the reflection of x through the line l(acting as a mirror) is equal to 2(projection of x onto r)-x I don't know how to set this up. -x=2(projection of x onto ...
January 24, 2011

marketing
3M's main market for promoting this produc were college students. Their goal was to raise awareness of the Post-it flag highlighters within the the college community as much as possible. They used print ads in college newspapers and TV ads and relayed on word of mouth ...
January 24, 2011

Physics
A golf ball is chipped at an angle of 49 degrees and with a speed of 8.5 m/s. How far does it travel to the nearest tenth of a meter?
January 23, 2011

chem
At 20 degrees celsius the vapor pressure of dry ice is 56.5atm. If 10 g of dry ice (solid CO2) is placed in an evacuated 0.25 L chamber at a constant temperature of 20 degrees celsius, will all of the solid sublime? Is the answer no? I don't know if this is right, but I ...
January 22, 2011

Chemistry
What do I do when writing the net ionic equation for Magnesium nitrate reacted with sodium chloride? I've wrote out the molecular equation and the total ionic equation. Everything cancels out....under my total ionic equation do i just write no reaction? |thanks!
January 19, 2011

physics
two masses m' each are hanging with help of a light string,which passes over mass less pulley. mass A starts leaking out at a rate of u kg/s with velocity v' with respect to mass A. find kinetic energy of block B as a function of time.
January 16, 2011

physics
a student standing on the roof of a 50 meter high building kicks a stone at a horizontal speed of 4 meters per second, how much time is required for the stone to reach the level ground below?
January 16, 2011

grammar
Ok thanks, so there are only two avderbs in this entire paragraph?
January 13, 2011

grammar
Need to identify five adverbs in this paragraph. I think I am correct but would like a second opinion. Thanks for your thoughts. LITTLE FOCKERS is the “continued” (adverb) antics of Greg and Pam Focker (Ben Stiller and Teri Polo) who “now” (adverb) have two...
January 13, 2011

nuclear engineering
Determine the amount of energy required (in MeV) to dissociate the following elements into component parts (protons, neutrons and electrons) • Hydrogen • Deuterium • Tritium
January 13, 2011

Math
Solve the proportion for u. (u-2):(u+3) = 4:3
January 12, 2011

math
On the unit circle the coordinates of P(theta) are (0.588, 0.809). Find the coordinates of P(2theta). Please help.
January 11, 2011

Math
A sweepstakes posted the odds and payoffs. Suppose that mailing the sweepstakes costs $0.33 and the odds in favor of winning the various prizes are listed in the chart below. What is the expected value of the sweepstakes for any individual? Considering the postage, is the ...
January 11, 2011

math
Can the expression (r-3)(s+2) be simplified without knowing the values of r and s?
January 10, 2011

math
If the probability of an event happening is 1/7, what are the odds against it happening? What is the ratio of the odds against the event?
January 10, 2011

Algebra
Two questions? Build a patio-hypotenuese is 50 feet long the two sides of patio are same. What is the length of one side of the patio I think I set it up a^2 + b^2 = c^2 a^2 + b^2 = 50^2 a^2+ b^2 = 2500 then I just could say 2a^2 = 2500 a^2 = 2500/2 a^2 = 1250 sqrt of 1250 = ...
January 5, 2011

Chemistry
I've got 21.2L, but supposedly correct answer is 21.7L. How?
December 13, 2010

Chemistry
Given 20.0 L of ammonia gas at 5C and 730 torr, calculate the volume at 50C and 800 torr
December 13, 2010

science
Chapter 1 & 2 Review Questions 1. Compare and Contrast the two main branches of physical science. 2. Distinguish between scientific laws and scientific theories. 3. Describe the steps of the scientific method. 4. Explain the objective of a consistent system of units, and ...
December 13, 2010

math
if possible, change each comparison of concentrate to water into a ratio. If not, explain why. a. the mix is 60% concentrate. b. the fraction of the mix that is water is 3/5 c. the difference between the amount of concentrate and water is 4 cups
December 7, 2010

accounting
Does the flexible budget term mean A series of budgets for varying rates of activity?
December 7, 2010

math
if you have a apple juice mix of 5 cups concentrate to 8 cups water, if you only make 1 cup of mix, how much water and how much concentrate do you need?
December 6, 2010

10th grade
How many grams of cacl2 are in 4.3l solution of 2.8 m cacl2
December 3, 2010

physics
thank you so much!!!
December 2, 2010

physics
yes i understand A but in B it's increasing the speed at a rate (which means acceleration) of 1.45 m/s^2 and thats where i get lost
December 2, 2010

physics
(A.) A hawk flies in a horizontal arc of radius 13.4 m at a constant speed of 4.5 m/s. Find its centripetal acceleration. Answer in units of m/s2. (B.) It continues to fly along the same horizon- tal arc but increases its speed at the rate of 1.45 m/s2. Find the magnitude of ...
December 2, 2010

physics
(A.) A hawk flies in a horizontal arc of radius 13.4 m at a constant speed of 4.5 m/s. Find its centripetal acceleration. Answer in units of m/s2. (B.) It continues to fly along the same horizon- tal arc but increases its speed at the rate of 1.45 m/s2. Find the magnitude of ...
December 2, 2010

physics
Wouldn't it be zero. It's speed at the top and bottom are zero so...
December 2, 2010

Earth Science
Describe how Earth would be different today if it contained no radioactive material. What would the consequences be for the Earth’s interior layers?
December 2, 2010

Physics
When empty, a particular helicopter of mass 3770 kg can accelerate straight upward at a maximum acceleration of 1.29 m/s2. A careless crewman overloads the helicopter so that it is just unable to lift off. What is the mass of the cargo?
November 28, 2010

chemistry
thanks! that helped me solve the problems.
November 27, 2010

chemistry
i am doing problems for chemistry class, and some of them are Calculating square root/ Cube Root but some are 4 and 5 instead of 2 or 3. if in a problem the exponent is 4 or 5 how would i use my calculator to calculate the root?
November 27, 2010

chemistry
sorry, answer found. no longer need help..
November 24, 2010

chemistry
The pH of a solution that contains 0.818 M acetic acid (Ka = 1.76 x 10-5) and 0.172 M sodium acetate is __________. The Ka of acetic acid is 1.76 × 10-5.
November 24, 2010

chemistry
The pH of a solution that contains 0.818 M acetic acid (Ka = 1.76 x 10-5) and 0.172 M sodium acetate is __________. The Ka of acetic acid is 1.76 × 10-5.
November 24, 2010

chemistry
The pH of a solution that contains 0.818 M acetic acid (Ka = 1.76 x 10-5) and 0.172 M sodium acetate is __________. The Ka of acetic acid is 1.76 × 10-5.
November 23, 2010

chemistry
The solubility of lead (II) chloride (PbCl2) is 1.6 x 10^-2 M. What is the Ksp of PbCl2?
November 22, 2010

Math
A ramp of length 6, width 4, and height 2.
November 21, 2010

Math
Calculate the volume of the ramp in Figure 17 in three ways by integrating the area of the cross sections: (a) Perpendicular to the x-axis (rectangles) (b) Perpendicular to the y-axis (triangles) (c) Perpendicular to the z-axis (rectangles)
November 21, 2010

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