Saturday

April 25, 2015

April 25, 2015

Number of results: 19,803

**Chemistry - please help!**

1)Ethanol is made by the fermentation of sugar. (a)Suggest a temperature for carrying out the fermentation and explain your answer. -40C(ish), ??to do with enzymes; they can't or don't work as well in other temps./controls the speed of fermentation (b)Why is it important that...
*April 20, 2008 by Anonymous*

**Chemistry**

Consider the following reaction: CO(g)+H2O(g)⇌CO2(g)+H2(g) Kp=0.0611 at 2000 K A reaction mixture initially contains a CO partial pressure of 1348torr and a H2O partial pressure of 1780torr at 2000 K. Calculate the equilibrium partial pressure of CO2. Calculate the ...
*February 25, 2015 by Ryan*

**Physics**

Consider a charging capacitor made out of two identical circular conducting plates of radius 21 cm. The plates are separated by a distance 8 mm (note that d<<a). The bottom plate carries a positive charge Q(t)= Q0(1+t/T) with Q0 = 5e-06 C and T = 0.005 sec, and the top ...
*May 24, 2013 by Flux*

**Physical Chemistry**

When the reaction glucose-1-phosphate (aq) --> glucose-6-phosphate (aq) is at equilibrium at 25.0 degrees celcius, the amount of glucose-6-phosphate present is 95% of the total. A.) Calculate the Standard Delta G at 25.0 degrees celcius. B.) Calculate Delta G for the ...
*October 20, 2006 by Angela*

**chemistry**

a student synthesized 6.895g of barium iodate monohydrate, Ba(IO3)2.H2O, by adding 30.00 mL of 5.912*10^-1M barium nitrate, Ba(NO3), to 50.00 mL of 9,004*10^-1 M sodium iodate, NaIO3 (1) write the chemical equation for the reaction of solutions of barium nitrate and sodium ...
*March 1, 2010 by aymal*

**math**

A glass in the form of a frustum of a cone is represented by the diagram below. The glass contains water to height of 9 cm. The bottom of the glass is circle of radius 2cm while the surface of the water is a circle of radius 6 cm. (a) Calculate the volume of the water in the ...
*June 3, 2012 by Anonymous*

**Math -Quadratics Help!**

I have a test tomorrow with a few sample questions that are expected to be on the test that I do not know how to properly do. 1)Find the slope intercept equation of the line passing through the intersection of the lines 2x-4y=1 & 3x+4y=4 and parallel to the line 5x+7y+3=0 2)...
*March 23, 2014 by JBregz*

**physics**

(a) calculate the number of kilocalories needed to climb 232 stair steps (116 steps per minute for 2 min.) *climbing stairs (116/min.) = energy consumption rate is 9.8 (kcal/min) * (b) calculate the gain in gravitational potential energy for a 50-kg person if each step 0.18m ...
*May 4, 2012 by sara*

**Circuits**

I need to calculate the voltage through the resistor and the voltage through the inductor of an RL series circuit for different frequencies. The voltage of the source is 2.5 V. The inductor is at the top and has an inductance of .200 H and the resistor is at the right with a ...
*March 24, 2012 by Heather*

**Circuits**

I need to calculate the voltage through the resistor and the voltage through the inductor of an RL series circuit for different frequencies. The voltage of the source is 2.5 V. The inductor is at the top and has an inductance of .200 H and the resistor is at the right with a ...
*March 24, 2012 by Heather*

**CHEM 136**

A sample of 25.00 mL of 0.100 M HNO2(in a flask) is titrated with 0.150 M of NaOH solution at 25 degrees. 1) calculate the volume(Ve) of the NaOH solution needed to completely neutralize the acid in the flask. 2)calculate the pH for (a)the initial acid solution in the flask (b...
*November 23, 2010 by Jefferson*

**Chemistry**

Please!!! its extremely urgent. i do not need answers, only how to do it A sample of nitrogen gas (N2) kept in a container of volume 10.1 L and at a temperature of 20.3C exerts a pressure of 3.1 atm. Calculate the number of grams of gas present. Round to one decimal place, do...
*October 17, 2011 by Javier*

**Math**

Indigo Industrial, Inc. is trying to determine which, if any, of five different projects it should undertake. Indigo Industrial has a 8.25% required rate of return on projects that it undertakes. The projected cash flows for each of the projects are given in the table below: ...
*April 19, 2014 by Jeremy*

**CHEMISTRY**

Suppose that 30.0 mL of 0.20 M C6H5COO(aq) is titrated with 0.30 M KOH(aq). a) What is the initial pH of the 0.20 M C6H5COOH(aq)? b) What is the pH after the addition of 15.0 mL of 0.30 M KOH(aq)? c) What volume of 0.30 M KOH(aq) is required to reach halfway to the ...
*September 29, 2011 by Sarah*

**science**

A parachutist bails out and freely falls 50m. Then the parachute opens and thereafter she decelerates at 2 m/s^2. She reaches the ground with a speed of 3m/s. a) how long is the parachutist in the air? b)At what height does the fall begin? for a) would I use x-x0 =vt-1/2 at^2 ...
*September 17, 2006 by jenny*

**General Chemistry-Acids/Bases**

I'm stuck on a couple of similar problems involving pH and acids/bases 1) What is the final pH of a 1L solution that is initially .15 M HF and .2 M NaF after 10 mL of .02 M HCl has been added? Ka=7.2x10^-4 Do i just calculate the total mols of H and divide by the volume, then ...
*November 26, 2008 by Evelyn*

**Macroeconomics**

Kelly purchased ten shares of Gentech stock for $200 in year 1 and sold all the shares in year 2 for $220 a share. Between year 1 and year 2, the price level increased by 5%. The tax on capital gains is 50%. If the capital gains tax is on nominal gains, calculate how much tax ...
*May 20, 2008 by Jay*

**advanced functions HELP!!!**

the function S(d)=93logd+65 relates the speed of the wind, S, in mile per hour, near the centre of a tornado to the distance that the tornado travels, d, in miles. a)Calculate the avg. rate of change for the speed of the wind at the centre of a tornado from mile 10 to mile 100...
*December 10, 2008 by james*

**Chemistry**

Arginine O 2.01 H2N---CH--C----OH 9.02 CH2 CH2 CH2 NH 12.48 C==NH NH2 ________________________________________ 9.78 O 2.35 H2N----CH---C----OH CH3 Glycine ________________________________________ Shown above are images of two amino acids, along with the pKas of each of their ...
*January 11, 2013 by Chemgam*

**physics**

An open-topped tank completely filled with water has a release valve near its bottom. The valve is 1.63 m below the water surface. Water is released from the valve to power a turbine, which generates electricity. The area of the top of the tank, AT, is a = 12.3 times the cross...
*October 25, 2011 by melisa*

**Applied Programming**

APPLIED PROGRAMMING (APR520S) ASSIGNMENT 1 Problem Solving Tools Total Marks: 50 Marks Due: Friday 22 August 2014 Suppose we want to construct a C/C++ program that can be used to calculate the area or the volume for a range of 2-D and 3-D shapes respectively. Consider only the...
*August 19, 2014 by Pineas*

**math**

the+base+jk+of+an+isosceles+triangle+hjk+is+produced+to+l+if+j+%3D69+degree+calculate+hkl&es_nrs=true&pf=p&sclient=psy-ab&oq=the+base+jk+of+an+isosceles+triangle+hjk+is+produced+to+l+if+j+%3D69+degree+calculate+hkl
*March 13, 2013 by Anonymous*

**Math - Quadratics & Analytical Geometry**

I have a test tomorrow with a few sample questions that are expected to be on the test that I do not know how to properly do. 1)Find the slope intercept equation of the line passing through the intersection of the lines 2x-4y=1 & 3x+4y=4 and parallel to the line 5x+7y+3=0 2)...
*March 23, 2014 by Jay*

**Chem 20**

Calculate the mass of strontium hydroxide required to make a 450-mL solution with a pOH of 4.00. Step 1: Find pOH. I found that pOH is 10. The next steps is where I'm stuck. Step 2 :Calculate the hydroxide ion concentration. Express your answer in scientific notation. Spell ...
*November 29, 2010 by Anonymous*

**physics**

. Consider a large number, N(0) , molecules contained in a volume V (0) . Assume that there is no correlation between the locations of the molecules (ideal gas). Do not use the partition function in this problem. (a) Calculate the probability P (V; N) that an arbitrary region ...
*June 13, 2011 by esmat*

**economics**

(2 points) Suppose that the following equations describe an economy (C, I, G, T, and Y are measured in billions of dollars and r is measured in percent; for example, r = 10 means r = 10%) 1700.6 200 1004 350...
*August 16, 2010 by kojo*

**Math "Ms Sue"**

The stem-and-leaf plot shows the heights in centimeters of Teddy Bear sunflowers grown in two different types of soil. Soil A Soil B 5 | 9 5 2 1 1| 6 | 39 510 | 7 | 023678 21| 8 | 3 0| 9 Key: 9|6 means 69,Key: 5|8 means 58 a) Describe the overlap of the two sets of data. b) ...
*May 2, 2014 by moby*

**physics help!**

A small 520-gram ball on the end of a thin, light rod is rotated in a horizontal circle of radius 1.5 m. Calculate the moment of inertia of the ball about the center of the circle. Then calculate the torque needed to keep the ball rotating at constant angular velocity if air ...
*March 25, 2010 by Anonymous*

**Finance**

Capital Budgeting Problems I. Indigo Industrial, Inc. is trying to determine which, if any, of five different projects it should undertake. Indigo Industrial has a 8.25% required rate of return on projects that it undertakes. The projected cash flows for each of the projects ...
*April 19, 2014 by Jeremy*

**accounting**

Computing in the Business World Suppose you are opening a 1,000 square foot baseball card store in a shopping center. You have signed a lease that requires you to pay a monthly rent of $1.75 per square foot, plus 5% of your gross annual sales. What is the total amount of rent ...
*August 29, 2006 by annonymous*

**physics**

I need help attacking this problem A steel ball is dropped onto a hard floor from a height of 1.95 m and rebounds to a height of 1.87 m (assume positive direction is upward) A. Caculate it's velocity just before it strikes the floor B. calculate it's velocity just after it ...
*September 21, 2014 by Edward*

**physics**

A ball of circumference 74.2 cm and mass 605 g is forced to the bottom of a swimming pool and then released. After initially accelerating upward, it rises at a constant velocity. (The density of water is 103 kg/m3.) (a) Calculate the buoyant force on the ball. (Indicate the ...
*April 16, 2011 by HELP!!!!*

**Chemistry**

Sodium metal dissolves in liquid mercury to form a solution called a sodium amalgam. The densities of Na(s) and Hg(l) are 0.97 g/cm3 and 13.6 g/cm3, respectively. A sodium amalgam is made by dissolving 1.0 cm3 Na(s) in 20.0 cm3 Hg(l). Assume that the final volume of the ...
*December 11, 2011 by bernan*

**Chmistry**

Sodium metal dissolves in liquid mercury to form a solution called a sodium amalgam. The densities of Na(s) and Hg(l) are 0.97 g/cm3 and 13.6 g/cm3, respectively. A sodium amalgam is made by dissolving 1.0 cm3 Na(s) in 20.0 cm3 Hg(l). Assume that the final volume of the ...
*December 13, 2011 by bernan*

**Statistics**

A Manufacturer of torque converters claim only 1% of them are defective. A. Calculate the Mean number of defective converters in a shipment of 500 converters. B. Calculate the standard deviation in the defective torque converters in a shipment of 500 converters. C. Would it be...
*March 26, 2013 by Bill*

**STATISTICS(NEED HELP PLEASE?)**

Consider the following set of data. (25, 6), (25, 51), (62, 34), (84, 15), (112, 57), (122, 14) (a) Calculate the covariance of the set of data. (Give your answer correct to two decimal places.) 40.17 (b) Calculate the standard deviation of the six x-values and the standard ...
*July 25, 2012 by Kim*

**physics**

An open-topped tank completely filled with water has a release valve near its bottom. The valve is h = 1.9 m below the water surface. Water is released from the valve to power a turbine, which generates electricity. The area of the top of the tank, A_T, is 38 times the cross-...
*November 27, 2012 by Brandon*

**physics**

A strip of rubber originally 75 mm long is stretched until it is 100 mm long. a.What is the tensile strain b.Why has the answer no units? c.The greatest tensile stress which steel of a particular sort of a particular sort can withstand without breaking is about 10>9 N m>...
*December 27, 2013 by farid*

**Chemistry**

A mixture of BaCl2.2H2O (FM244.26) and K2SO4 (FM 174.26) is heated at 160C for an hour, causing the water molecules to leave. A sample originally weighing 2.0027 g weighed 1.9021 g after heating. Calculate the mass percent K2SO4 in the sample. In a previous practice example, I...
*September 28, 2011 by Asuna*

**Math/Physics(Please check work)**

For an experiment on specific heat capacities of metal in physics, I am trying to calculate my percent error but am having some trouble. After collecting my experimental data for c (cal/g) for the object that was used which was aluminum my results are: trial 1 = .19 trial 2...
*November 1, 2012 by Hannah*

**Physics**

Consider a car is heading down a 5.5 slope (one that makes an angle of 5.5 with the horizontal) under the following road conditions. You may assume that the weight of the car is evenly distributed on all four tires and that the coefficient of static friction is involvedthat...
*February 21, 2014 by Maura *

**Physics**

After the Sun exhausts its nuclear fuel, its ultimate fate may be to collapse into a white dwarf state. In this state, it would have approximately the same mass as it has now, but its radius would be equal to the radius of earth. (a) Calculate the average density of the white ...
*October 4, 2011 by bob*

**Chem**

How many chlorine atoms are in 5.0 g of C2H3Cl3O2? What mass of C2H3Cl3O2 would contain 1.0g Cl? There are 6.02 x 10^23 atoms in a mole of anything. Calculate the molar mass of your compound, that mass will contain 6.02 x 10^23 molecules of that material (whatever it is), then...
*December 9, 2006 by Min*

**physics**

A 28.0 block is connected to an empty 2.20 bucket by a cord running over a frictionless pulley. The coefficient of static friction between the table and the block is 0.44 and the coefficient of kinetic friction between the table and the block is 0.35. Sand is gradually added ...
*October 31, 2011 by xxx*

**chemistry **

1)Calculate the pH of a 0.10 M NaHX salt solution. Ka (H2X) = 2.1 x 10-2 Ka (HX-) = 4.5 x 10-8 2)Calculate the pH of a 0.10 M NaHX salt solution. Ka (H2X) = 5.3 x 10-5 Ka (HX-) = 5.3 x 10-11
*October 21, 2011 by yahn*

**chemistry**

Calculate the pH of a 0.10 M NaHX salt solution. Ka (H2X) = 2.1 x 10-2 Ka (HX-) = 7.3 x 10-8 Calculate the pH of a 0.10 M NaHX salt solution. Ka (H2X) = 9 x 10-5 Ka (HX-) = 5.3 x 10-11
*March 11, 2012 by Anonymous*

**Epidemiology**

Design the appropriate 2x2 table, calculate and interpret the appropriate measure of association. You suspect that the association between alcohol use and CHD might be confounded by smoking. You collect the following data: Smokers Non-Smokers CHD No CHD CHD No CHD Alcohol Use ...
*October 19, 2010 by Latice*

**research and evaluation class**

describe joint probability for independent events and give an example of how you would calculate it. How is this different than conditional probability? The following payoff table gives the return on three alternative business decisions based on three possible scenarios down...
*November 18, 2010 by sue*

**programming**

Create an application in C# that will accept sales information and calculate the total bill. There are 3 products which can be sold: Product 1 with price of $2.98 Product 2 with price of $4.50 Product 3 with price of $9.75 The application should prompt the user for product and...
*September 30, 2012 by Todd*

**Math**

Which is the better investment over a y year term? Calculate each one. Investment that offers a rate of 2.25% per annum, compounded semi-anually. Investment that offers a rate of 2.15% per annum, compounded quarterly. Investment that offers a rate of 1.95% per annum, simple ...
*January 29, 2013 by Ais*

**Math help! **

Which is the better investment over a y year term? Calculate each one. Investment that offers a rate of 2.25% per annum, compounded semi-anually. Investment that offers a rate of 2.15% per annum, compounded quarterly. Investment that offers a rate of 1.95% per annum, simple ...
*January 29, 2013 by Ais*

**chemistry**

1-Dinitrogen tetroxide (N2O4) dissociates according to the equation: N2O4 ⇌ 2NO2 An equilibrium reaction mixture at 25 C was found to have the partial pressure of N2O4 as 72 kPa whilst the partial pressure of nitrogen dioxide (NO2) was 29 kPa. Calculate Kp for the ...
*July 27, 2014 by John*

**chemistry**

Record and calculate the following masses: (a)mass of empty beaker: 47.420g (b)mass of beaker plus Na₂CO₃:47.920g (c)Mass of Na₂CO₃:0.5g (d)mass of beaker plus NaCl:47.438g (e) Mass of NaCl (g):0.018g **I need help with these questions below** 2. ...
*June 7, 2012 by chelsea*

**Chemistry**

A standard solution with a FeSCN2+ concentration of 1.55x10^-4M has a percent transmittance (%T) of 18.8%. Another solution of unknown FeSCN2+ concentration has a percent transmittance of 44.8%. A) Calculate the absorbance (A) of each solution. B) Using the absorbances ...
*February 26, 2014 by Dan*

**Chemistry**

1. Consider the conductance meter and the titration method of determining the salt content of a brine sample. Discuss at least two advantages and two disadvantages of each method. 2. A corrosion technologist pipetted a 50.00 mL sample of an unknown brine and titrated it with ...
*July 1, 2011 by Shannon*

**physics**

Proponents of astrology claim that the positions of the planets at the time of a baby's birth will affect the life of that person in important ways. Some assert that this effect is due to gravity. Examine this claim with Newton's law of gravity. Calculate the maximum force ...
*March 15, 2009 by cb*

**physics charges. please help!**

A charge Q = +4.5 uC is located at the origin and is fixed so that it cannot move. A small object with mass m = 2.0 g and charge q = +8.0 uC is released from rest at point A on the x-axis at x = 2.0 cm. The small object moves without friction along the x-axis under the ...
*November 12, 2012 by Matt*

**chemistry pls help me asap**

100cm^3 of a sodium hydroxide,NaOH solution contains 4.0g of solid sodium hydroxide,NaOH.40 cm^3 of phosphoric acid,H3PO4 is needed to neutralise 40cm^3 of the alkali.(RAM:H,1;O,16;Na,23;P,31) (a)Calculate the molarity of the sodium hydroxide,NaOH solution. (b)Calculate the ...
*May 7, 2014 by mandy*

**Physics**

A 28.0kg block is connected to an empty 1.80kg bucket by a cord running over a frictionless pulley. The coefficient of static friction between the table and the block is 0.41 and the coefficient of kinetic friction between the table and the block is 0.35. Sand is gradually ...
*September 25, 2009 by Ashley*

**Chemistry**

0.717 g of a compound containing carbon, hydrogen, and oxygen is burned and found to produce 1.02 g CO2 and 0.624 g H2O. The molar mass of the compound is 124 g/mol. (a) Write a chemical equation for the combustion of this unknown hydrocarbon. (b) Determine the # of g and ...
*August 24, 2011 by Franklin*

**University of Belize**

5. A 0.500 g sample of a BaCl22H2O/Na2SO4 salt mixture, when mixed with water, filtered, and dried, produced 0.225 g of BaSO4. The Na2SO4 was determined to be the limiting reactant. a. Calculate the mass, in grams, of Na2SO4 in the mixture. b. Calculate the mass, in grams, ...
*October 29, 2013 by sarah*

**Chemistry**

How can i calculate the concentration of each ions remaining in the solution after precipitation is complete? ok heres the full question:: 2KOH + Mg(NO3)2 -------------> 2KNO3 + Mg(OH)2 a 100.0 mL aliquot of 0.200 M aqueous potassium hydroxide is mixed with 100.0mL of 0....
*August 23, 2010 by Crickett*

**chemistry**

How can i calculate the concentration of each ions remaining in the solution after precipitation is complete? ok heres the full question:: 2KOH + Mg(NO3)2 -------------> 2KNO3 + Mg(OH)2 a 100.0 mL aliquot of 0.200 M aqueous potassium hydroxide is mixed with 100.0mL of 0....
*August 23, 2010 by Crickett*

**chemistry**

How can i calculate the concentration of each ions remaining in the solution after precipitation is complete? ok heres the full question:: 2KOH + Mg(NO3)2 -------------> 2KNO3 + Mg(OH)2 a 100.0 mL aliquot of 0.200 M aqueous potassium hydroxide is mixed with 100.0mL of 0....
*August 24, 2010 by Crickett*

**Chemistry**

How can i calculate the concentration of each ions remaining in the solution after precipitation is complete? ok heres the full question:: 2KOH + Mg(NO3)2 -------------> 2KNO3 + Mg(OH)2 a 100.0 mL aliquot of 0.200 M aqueous potassium hydroxide is mixed with 100.0mL of 0....
*August 24, 2010 by Crickett*

**Chem**

A solution is made by dissolving 26.9 g of NaOH in approximately 450 mL of water in a volumetric flask. The solution becomes quite warm, but after it is allowed to return to room temperature, water is added to total 500 mL of solution. Calculate the pH of the final solution. ...
*February 27, 2013 by Anonymous*

**Math-DrBob222**

Healthy food Inc sells 50lb bags of grapes to the military for $10 a bag. The fixed costs of this operation are $80,000 while the variable costs of the grapes are $10 per lb. 1.Calculate the profit or loss on 12,000 bags and on 25,000 bags. Can you please walk me through on ...
*July 11, 2009 by janay1978*

**Phyiscs **

Please show work You decide to take a nice hot bath but discover that your thoughtless roommate has used up most of the hot water. You fill the tub with 270 kg of 30.0C water and attempt to warm it further by pouring in 5.00 kg of boiling water from the stove. (a) Is this a ...
*July 15, 2010 by Anonymous*

**Physicss **

Please show work You decide to take a nice hot bath but discover that your thoughtless roommate has used up most of the hot water. You fill the tub with 270 kg of 30.0C water and attempt to warm it further by pouring in 5.00 kg of boiling water from the stove. (a) Is this a ...
*July 15, 2010 by Anonymous*

**PChem**

For the gas phase reaction 2NO2 + F2 2NO2F, the rate constant is k= 38 dm3/mol-s at 27 oC. The reaction is first-order in NO2 and first-order in F2. A) Calculate the number of moles of NO2, F2, and NO2F after 10.0 s if 2.00 mol of NO2 is mixed with 3.00 mol of F2 in a 400 ...
*December 9, 2014 by Debora*

**Chemistry**

5.0 g of NaNO3 is dissolved in 50.0 g of water. The initial temperature of the water was 21 degrees Celsius and the final temperature of the water is 15.7 degrees Celsius. 1)Calculate the heat of solution, DeltaHsolution. 2) calculate the heat of solution, DeltaHsolution, per ...
*October 19, 2009 by Tom*

**Chemistry**

5.0 g of NaNO3 is dissolved in 50.0 g of water. The initial temperature of the water was 21 degrees Celsius and the final temperature of the water is 15.7 degrees Celsius. 1)Calculate the heat of solution, DeltaHsolution. 2) calculate the heat of solution, DeltaHsolution, per ...
*October 19, 2009 by Tom*

**chemistry**

5.0 g of NaNO3 is dissolved in 50.0 g of water. The initial temperature of the water was 21 degrees Celsius and the final temperature of the water is 15.7 degrees Celsius. 1)Calculate the heat of solution, DeltaHsolution. 2) calculate the heat of solution, DeltaHsolution, per ...
*October 19, 2009 by Tom*

**Chemistry - please this is urgent**

To a calorimeter containing 41.80g of water at 29.95oC, 11.7999 of a salt was added with stirring. As the salt dissolved, the temperature rapidly changed to 37.85oC before slowly returning to room temperature. 1. Calculate the Heat of Solution. Given that the Heat of Formation...
*March 14, 2008 by girl who needs help in chemistry right now*

**physics**

1. Calculate the frequency (Hz) and energy (eV) of green photons with wavelength of 555nm. Photon energy = hν, where ν = frequency in Hz and h = 6.626x10-34 joule-sec, the Plancks constant. Keep in mind that: wavelengthxfrequency = speed. 2. Andy Ruddick can serve ...
*March 1, 2009 by JeFF*

**physics**

a block of mass 2 kg and block B of mass 8 kg are connected by a spring of spring constant 80 N/m and negligible mass. The system is being pulled to the right across a horizontal frictionless surface by a horizontal force 4 N with both blocks experiencing equal constant ...
*June 9, 2008 by shelly*

**Physical Science**

A 28.0kg block is connected to an empty 1.80kg bucket by a cord running over a frictionless pulley. The coefficient of static friction between the table and the block is 0.41 and the coefficient of kinetic friction between the table and the block is 0.35. Sand is gradually ...
*September 28, 2009 by Brittany*

**statistics**

Suppose a new treatment for a certain disease is given to a sample of n=200 patients. The treatment was successful for 166 of the patients. Assume these patients are representative of the population of individuals who have this disease. (a) Calculate the sample proportion of ...
*April 5, 2012 by Kya*

**Physics**

I'm supposed to to calculate an experimental value for the acceleration of gravity from the slope of an acceleration vs. delta mass graph... also i'm supposed to find the percent error (to the normal acceleration of gravity of 9.8).. the slope is .442 i'm not sure how to do ...
*October 30, 2014 by Amber*

**Physics**

Calculate the effective value of g, the acceleration of gravity, at 6400m , above the Earth's surface. Calculate the effective value of g , the acceleration of gravity, at 6200km , above the Earth's surface
*October 2, 2009 by Lea*

**Physical Chemistry**

A 100 amino acid folded protein (F) is in equilibrium with its unfolded (U) (or denatured) form. Let ΔrH(std) =+347 kJ mol-1 and ΔrS(std) =-1010 J K-1 mol-1 for the equilibrium (F U) at 25℃. (a) Calculate the concentration of protein in each form if the total ...
*November 10, 2010 by KC*

**Chemistry**

need to calculate percent yield of MgNH4PO4 . 6H2O obtained in my experiment using 10-52-10 plant food label as a guide to determine the theoretical yield of MgNH4PO4 . 6H2O. My calculations so far: air dry weight of MgNH4PO4 . 6H2O = 2.30 g Grams of phosphorusin MgNH4PO4 ...
*May 27, 2011 by Julia*

**physics**

a jet pilot takes his aircraft in a vertical loop. a) if the jet is moving at a speed of 2000 km/h at the lowest point of the loop, determine the minimum radius of the circle so that the centripetal acceleration at the lowest point does not exceed 6.0g's b) calculate also the ...
*October 4, 2009 by jeffery*

**Chemistry**

I am beyond desperate. I do not understand how to calculate heat change at all and I have been looking online and reading my book for the last three hours. Below is posted a problem. It would be amazing if someone could work through it and explain each step they are doing and ...
*April 7, 2009 by Kathryn*

**AP Chemistry**

(a)calculate the mass percent of carbon in the hydrated form of the solid that has the formula BeC2O4 X 3 H2O (s). I divided 24.02 g by 151.08 g and got .16, or 16%. is that correct? Also, I'm having trouble with this follow up question. When heated to 220 degrees C, BeC2O4 X ...
*September 19, 2007 by Patrick*

**Business Finance - Check/Help**

Smith Manufacturing is considering the sale of two non depreciable assets, A and B. Asset A was purchased for $2000 and will be sold today for $2250. Asset B was purchased for $30,000 and will be sold today for $35000. The firm is subject to a 40% tax rate on capital gains. 1...
*September 11, 2011 by Sam*

**SCIENCE: GR.10 OPTICS CONVEX MIRRORS**

A convex security mirror has a focal length of -0.25m. A person with a height of 1.5m is 4m from the mirror. calculate the image distance and image height. AND An object 0.4m tall is placed 2.5m in front of a convex mirror that has a focal length of -90cm. Calculate image ...
*March 28, 2010 by lily*

**chemistry**

A sample containing 0.0500mol of Fe2(SO4)3 is dissolved in enough water to make 1.00L of solution. This solution contains hydrated SO4 2- and Fe(H2O)6 3+ ions. The latter behaves as an acid: Fe(H2O)6 3+ --> Fe(H2O)5OH 2+ + H+ a) Calculate the expected osmotic pressure of ...
*February 16, 2011 by Chris*

**Physics**

please can u check my answer Here are the questions: 1. A 0.45 kg book is resting on a dessktop 0.64 m high. Calculate the book's potential energy relative to a)the desktop? b)the floor. 2. A 0.636 kg basketball has a potential energy of 19J at teh basket. How high is teh ball...
*April 9, 2011 by Anonymous*

**Chemistry**

Hi, if anyone can give me help for any part of the question that would be great! I know how to draw the cell diagram, but am not sure what the half-reactions would be.... Here is the question: Give the cell diagram notation of the electrochemical cell that could be used to ...
*December 12, 2007 by Anne*

**Physic**

Two boxes sit side-by-side on a smooth horizontal surface. The lighter box has a mass of 5.91 kg, the heavier box has a mass of 7.67 kg. Calculate the contact force between these boxes when a horizontal force of 5.09 N is applied to the light box. and Calculate the contact ...
*September 22, 2009 by Timothy Tran*

**Chemistry**

Suppose that 30.0 mL of 0.20 M C6H5COOH(aq) is titrated with 0.30 M KOH(aq). (a) What is the initial pH of the 0.20 M C6H5COOH(aq)? (b) What is the pH after the addition of 15.0 mL of 0.30 M KOH(aq)? (c) What volume of 0.30 M KOH(aq) is required to reach halfway to the ...
*November 3, 2010 by Alania*

**physics**

A)Two boxes sit side-by-side on a smooth horizontal surface. The lighter box has a mass of 5.60 kg, the heavier box has a mass of 7.65 kg. Calculate the contact force between these boxes when a horizontal force of 4.83 N is applied to the light box. B)Calculate the contact ...
*February 12, 2014 by Sarah*

**physics**

water flows along a horizontal pipe of cross-sectional area 48cm^2 which has a constriction of cross-sectional area 12cm^2 at one place. If the speed of the water at the constriction is 4 m/s, calculate the speed in the wider section. The pressure in the wider section is 1.0 x...
*March 26, 2010 by Edwin*

**physics**

water flows along a horizontal pipe of cross-sectional area 48cm^2 which has a constriction of cross-sectional area 12cm^2 at one place. If the speed of the water at the constriction is 4 m/s, calculate the speed in the wider section. The pressure in the wider section is 1.0 x...
*March 26, 2010 by Edwin*

**chemistry**

a fire extignuisher produces carbon dioxide by the reaction between sodium hydrocarbonate and sulfuric acid. if a fire extinguisher is desgined to hold 600.0g of sodium hydrocarbonate calculate : the mass of sulfuric acid required to react with sodium hydrocarbonate AND ...
*April 17, 2010 by sarah *

**Physics**

Calculate the maximum deceleration of a car that is heading down a 30.0 slope (one that makes an angle of 30 with the horizontal) under the following road conditions. You may assume that the weight of the car is evenly distributed on all four tires and that the coefficient ...
*June 3, 2014 by Anonymous*

**Physics**

Calculate the maximum deceleration of a car that is heading down a 30.0 slope (one that makes an angle of 30 with the horizontal) under the following road conditions. You may assume that the weight of the car is evenly distributed on all four tires and that the coefficient ...
*June 3, 2014 by Anonymous*

**physics help me bob!**

A rock is thrown from the roof of a building with a velocity v0 at an angle α0. The height of the building is h. (i)Calculate the horizontal distance traveled by the projectile before it strikes the ground. (ii)Show that the speed of the rock just before it strikes the ...
*December 2, 2012 by dt*

**CHEMISTRY PLEASE HELP**

Using the data collected for part c on your data sheet and assuming the density of the vinegar is 1.00g/mL, 1) calculate the molar concentration of acetic acid (CH3COOH) in the vinegar sample using the average volume of NaOH. 2) calculate the mass percent of acetic acid in the...
*October 24, 2011 by Josh*