Friday

October 9, 2015
Number of results: 20,549

**physics**

in a tug of war a jeep of a mass 1400kg and a tractor of a mass of 2000kg pull on a horizontal rope in opposite directions. at one instant, the tractor pulls on the rope with a force of 1.50*10^4N while its wheels push horizontally against the groud with a force of 1.60*10^4N ...
*October 30, 2010 by jack*

**Physics**

A 2.50 kg fireworks shell is fired straight up from a mortar and reaches a height of 110. m. (a) Neglecting air resistance (a poor assumption, but we will make it for this example), calculate the shells velocity when it leaves the mortar. (b) The mortar itself is a tube 0.450...
*May 30, 2014 by Anonymous*

**physics**

at on time, the velocity of a rifle bullet was measured using a ballistic pendulum made up of a wooden block suspended from a string. the block used here has a mass of 20kg. a 50g rifle bullet is fired into the block, penetrating it by 10cm and causing it to swing upwards, ...
*September 2, 2010 by dave*

**Math HELP! 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, 2015 by Anon101*

**physics**

a toy train P of mass 3kg,is connected by a string to a wagon Q of mass 2kg.Thulu fastens a cable to P and pulls it with a force of 12N at an angle of 60degrees horizontally.the train moves over a wooden floor A frictional force of 2N act between the engineP and the floor ...
*May 15, 2011 by zanele*

**Chemistry**

I need help with two problems need helps please!! 1) Calculate the surface area in nm^2 of a water solution contained in a watch glass with a diameter of 5.6cm. Remember that the area of a circles is calculate as A=πr2 and diameter= 2r 2) If a molecule of stearic acid ...
*October 6, 2014 by Paul*

**Macro Help**

Calculating Marginal Propensity to Save and Marginal Propensity to Consume Consider the following table. For this hypothetical economy, the marginal propensity to save is constant at all levels of real GDP, and investment spending is autonomous. There is no government. Real ...
*May 12, 2008 by animal*

**Physics**

Assume it takes 6.00 minutes to fill a 45.0 gal gasoline tank. (1 U.S. gal = 231 in.3) I don't know how to solve for part C. (a) Calculate the rate at which the tank is filled in gallons per second. ANSWER: 0.125 (b) Calculate the rate at which the tank is filled in cubic ...
*October 4, 2009 by Zoe*

**Physics**

(1) body is taken to depth of 32km below the surface of the earth. Calculate the percentage decrease in the weight of the body at this depth (The radius of the earth is 6400km) (2)A wire of mass per unit length 5.0gm-1 is stretched between 2 points 30cm apart. The tension in ...
*July 26, 2008 by matrixxavier*

**Chemistry**

The DNA of an E coli cell measures 1.4 mm in length, when extended and 20 angstroms in diameter. a) Calculate the volume of DNA in an E coli cell in cm^3 b) What fraction of an E coli cell is occupied by its DNA? c) A human cell is typically spherical with a diameter of 20 ...
*September 7, 2009 by Janae*

**chemistry**

Calculate the change in pH when 4.00 mL of 0.100 M HCl(aq) is added to 100.0 mL of a buffer solution that is 0.100 M in NH3(aq) and 0.100 M in NH4Cl(aq). Delta pH=? Calculate the change in pH when 4.00 mL of 0.100 M NaOH(aq) is added to the original buffer solution. Delta pH=?
*July 8, 2012 by rachel*

**Chemistry**

Okay so I kinda understand where to put the numbers into the formula but i'm not sure how to calculate the distance so could someone kindly walk me through the problem so i can understand it. Thank you so much. Calculate the amount of energy required for the formation of one ...
*November 3, 2011 by Amanda*

**Mathematics**

Mr.Allen has a wife and 3 kids.His monthly salary during the year 2007 was $7500. a)Calculate his annual salary $90,000 is this right? Information on calculating income tax for 2007 is shown in the table shown Allowances:Husband-$10,000,Wife-$5000, Each child-$2500 Tax rate-22...
*June 23, 2009 by Sarah*

**Chemistry**

(A). A reaction with a known q is performed in a bomb calorimeter and is found that 10.0 kj of heat is required to raise the temperature of the calorimeter by 2.15 degrees C. calculate the heat capacity of the calorimeter. (B). When 1.00 g of C2H6(g) is burned in the bomb ...
*April 27, 2011 by Ben*

**Physics**

A hardworking ant must supply 0.00955 N to pull a small piece of fruit at constant velocity over a distance of 8.60 cm up a small hill to the entrance of the colony. If the coefficient of kinetic friction between the piece of fruit and the 16.2 sloped hill is 0.540, calculate...
*November 4, 2013 by Anonymous*

**Physics**

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 leaves the floor on its way back up C...
*September 18, 2014 by Edward*

**Physics**

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 leaves the floor on its way back up C...
*September 20, 2014 by Edward*

**physics**

Consider two N-turn circular coils of radius R, each perpendicular to the axis of symmetry, with their centers located at z=l/2 . There is a steady current I flowing in the same direction around each coil Assuming the N=100, I=2 Amperes, R=10 cm, l=2 cm calculate the ...
*April 8, 2013 by abdul rahman *

**chemisrty**

Q3) Consider a 10 L container at 0 oC with 40 grams of He and 40 grams of Ar gases: a) Calculate the partial pressure of Ar in the container? b) Calculate the partial pressure of He in the container? c) What is the total pressure of the container?
*January 16, 2012 by lyan*

**Physics**

The sun has a mass of 1.99x10 30 kg the earth has a mass of 5.98x10 24 kg and is 1.496x10 11 m from the sun a) Calculate the force of gravity acting on the eaarth by the sun b) CAlculate the force of gravity acting on the sun by the earth
*January 8, 2013 by Isis*

**math**

1. Calculate the interest charge on a $5,000 balance with your current 16.5% annual interest rate. 2. Calculate the interest charge on a $5,000 balance with the Visa Student Cards annual interest rate of 10.8%.
*May 7, 2013 by Mary*

**business statistics**

This select group has been asked to consider the Colorado City Convention and Visitors Bureau survey of 25 hotels in the local area. The survey is concerned with the current availability of rooms. The availability of the rooms was as follows: 90, 72, 75, 60, 75, 72, 84, 72, 88...
*April 27, 2012 by taabbie*

**Public Finance**

A corporation has $7 mil. in equity. During the tax year it takes in $4 million in receipts and earns $ 2 million in capital gains from sale of subsidiary. It incurs labor costs of $1 million, interest costs of $250,000, material costs of $500,000, and pays rent for structure ...
*January 29, 2011 by Mel*

**Chem Lab Help**

Trial #1 Trial #2 Trial #3 Mass: gelatin capsule (g) .123 .118 .122 Mass: whole alka-seltzer tablet (g) 3.230 3.230 3.230 Mass: capsule + alka-seltzer sample (g) .822 .882 .677 Mass: system before reaction (g) 23.109 23.110 22.735 Mass system after reaction (g) 21.742 21.813 ...
*October 29, 2012 by Tyler*

**Chemistry**

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 19, 2008 by Anonymous*

**chemistry**

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 19, 2008 by Anonymous*

**CHEMISTRY**

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*

**Physics**

A straight path is inclined at an angle of 15 degree to the horizontal. A loaded skip of total mass 1500 kg is at rest on the path and is attached to a wall at the top of the path by a rope. The rope is taut and parallel to a line of greatest slope of the path, as shown in the...
*February 19, 2013 by Josep*

**physics**

A flywheel with a diameter of 1 m is initially at rest. Its angular acceleration versus time is graphed in the figure. (a) What is the angular separation between the initial position of a fixed point on the rim of the flywheel and the point's position 8 s after the wheel ...
*March 20, 2011 by laila*

**physics**

A flywheel with a diameter of 1 m is initially at rest. Its angular acceleration versus time is graphed in the figure. (a) What is the angular separation between the initial position of a fixed point on the rim of the flywheel and the point's position 8 s after the wheel ...
*March 20, 2011 by Anonymous*

**physics**

A flywheel with a diameter of 1 m is initially at rest. Its angular acceleration versus time is graphed in the figure. (a) What is the angular separation between the initial position of a fixed point on the rim of the flywheel and the point's position 8 s after the wheel ...
*March 20, 2011 by HARD!!!!*

**AP Chemistry**

A 1.2M NaOCl solution is prepared by dissolving solid NaOCL in distilled water at 298K. The hydrolysis reaction OCl-(aq) + H2O(l) --> HOCl(aq) + OH-(aq) occurs. a. Calculate the value of the equilibrium constant at 298K for the hydrolysis reaction. b. Calculate the value of...
*February 17, 2010 by Anonymous*

**physics... part a on**

A diver descends from a salvage ship to the ocean floor at a depth of 35 m below the surface. The density of ocean water is 1.025x10^3 kg/m^3. a) Calculate the guage pressure on the diver on the ocean floor. b) Calculate the absolute pressure on the diver on the ocean floor. ...
*January 21, 2007 by johnny*

**Economics**

The marginal tax rate is defined as the extra taxes paid on additional income divided by the increase in income. Calculate the marginal tax rate for the proportional tax system as income rises from $50,000 to $100,000. Calculate the marginal tax rate as income rises from $100,...
*November 14, 2006 by Sally*

**physics**

A flywheel with a diameter of 1 m is initially at rest. Its angular acceleration versus time is graphed in the figure. (a) What is the angular separation between the initial position of a fixed point on the rim of the flywheel and the point's position 8 s after the wheel ...
*March 21, 2011 by Help..Help !!!!*

**Physics**

A man stands on the roof of a 19.0 m-tall building and throws a rock with a velocity of magnitude 24.0 m/s at an angle of 38.0 degrees above the horizontal. You can ignore air resistance. Calculate the maximum height above the roof reached by the rock. Got it.... 11.1 m ...
*September 17, 2006 by Josh*

**economics**

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 C=170+0.6(Y-T),T=200,I=100-4r,G=350 (M/P)d=L=0.75Y-6r, (M/P)s=735 a. Derive the equation for the IS curve (Hint: ...
*August 16, 2010 by yaw*

**Physics**

What is the force of gravity at 220 miles above Earth's surface? Calculate how much of a g force the astronauts are actually experiencing. The solution for this math problem is a percentage. You can calculate it using the Algebraic equation: gr = R2/r2 x g R = the radius of ...
*January 22, 2011 by John*

**Please help with 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*

**epidemiology**

In another study, the smoking habits of 34,445 male physicians were obtained by mailed questionnaires. Deaths among these physicians over the subsequent years were identified though contact with the office of the Registrar General. The death rates from lung cancer of these ...
*April 27, 2014 by Tracy*

**Engineering science**

a 50kg mass is suspended from a spring, causing it to extend by 30mm. calceolate the spring stiffness? The mass is then pulled down a distance of 90mm and released. calculate the frequency of the resulting motion, assuming that this is simple harmonic, calculate the velocity ...
*June 9, 2014 by James *

**cheistry - 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 - 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*

**physics **

A car is traveling at a constant velocity of 21 m/s (about 45 mph). The driver sees a fallen tree lying across the road and hits the brakes after a delay (reaction time) of 245 ms. (1 ms = 10-3 s.) Calculate the distance the car travels during this 245 ms reaction time period...
*September 23, 2015 by rosy*

**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*

**physics**

qustion(1):A rectangular face of a casting 250mmx100mm is to be machined on a sharper.if the average cuting speed is to be 20m/min and the feed is to be 2mm/stroke,calculate the time taken to machine the face of casting.allow 5mm overun at each end of the stroke. question(2):...
*August 8, 2015 by edward*

**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*