Thursday

April 2, 2015

April 2, 2015

Total # Posts: 260

**Math**

Can you please solve it for me? Im still a bit confused...
*March 30, 2015*

**Math**

In a deck of 52 cards, 3 cards are chosen. What is the probability that all three card are picture cards? (king, queen, jack) By the way, we are learning combinations and permutations. Help would be greatly appreciated!
*March 30, 2015*

**Geometry **

In a triangle, we have line QR parallel to line ST, PQ = 8, QS = 6, and PT = 12. Find PR.
*March 29, 2015*

**Math**

In triangle ABC, points X and Z are on line AB and Y is on line AC such that line XY is parallel to line BC and line ZY is parallel to line XC. If AZ = 8 and ZX = 4, then what is XB?
*March 28, 2015*

**Maths- Proof**

I understand thanks!
*March 5, 2015*

**Maths- Proof**

The question is: Prove algebraically that the difference between the squares of any two consecutive even numbers is always a multiple of 4. My working was: Let the numbers be n and n + 2 (n+2)^2 - (n)^2 =n^2 + 4n + 4 - n^2 =4n + 4 =4(n + 1) But the answers say the numbers ...
*March 5, 2015*

**algebra**

A coffee merchant sells a customer 3 lb of Hawaiian Kona at $9.75 per pound. The merchant's scale is accurate to within ±0.03 lb. By how much could the customer have been overcharged or undercharged because of possible inaccuracy in the scale? (Round your answer to ...
*February 10, 2015*

**algebra**

Mary has $4.00 in nickels, dimes, and quarters. If she has twice as many dimes as quarters and forty-seven more nickels than dimes, how many coins of each type does she have?
*February 10, 2015*

**statistics**

A company has four production sections viz., S1, S2, S3 and S4 which contribute 30%, 20%, 28% and 22% of the total output. It was observed that those sections respectively produced 1%, 2%, 3% and 4% defective units. If a unit is selected at random and found to be defective, ...
*February 4, 2015*

**Physics**

A flat disk 1.0 m in diameter is oriented so that the plane of the disk makes an angle of pi/6 radians with a uniform electric field. if the field strength is 589.0 N/C, find the electric flux through the surface. I know that Flux=(integral)|E|cos(theta)dA but I'm not sure...
*February 3, 2015*

**civil engineering **

Two masses are connected by a light cord over a frictionless pulley as shown. If M1 = 8.9 kg and M2 = 5.7 kg, calculate the tension in the cable (in N). Take the coefficient of kinetic friction between M1 and the horizontal surface to be 0.3 and assume the acceleration due to ...
*January 23, 2015*

**Physics C**

A charged particle is released from rest in a region that has a uniform electric field of magnitude 64.0 N/C. After traveling a distance of 0.500 m in this region, the particle has a kinetic energy of 0.880 J. The charge on the particle is _______ C
*January 14, 2015*

**CAL-Critical points**

For the function F(x) = inx/x^2 , find the approximate location of the critical point in the interval (0, 5).
*December 29, 2014*

**Chemistry**

Benzene, C6H6, consists of six member ring of sp2 hybridized p orbital. How many (pi)_2p bonding, anti bonding, and nonbonding molecular orbitals exist for benzene?
*December 11, 2014*

**Chemistry**

Calculate the percent purity of a sample of zinc metal if 325 mL of hydrogen gas is collected by water displacement at a temperature of 22.0 C and an atmospheric pressure of 745.0 mm Hg when 1.12 g of the sample is reacted with excess HCl: Zn + 2 HCl = H2 + ZnCl2. The vapor ...
*December 11, 2014*

**Calculus- Tangent Line- STEVE**

Yeah... my review didn't give me many other information besides this, thats why I was a bit unsure if my answer was correct.
*December 9, 2014*

**Calculus- Tangent Line**

What is the slope of the tangent line to the curve at the point (4, 0)? Okay, so I got 0.5, did I do this right?
*December 9, 2014*

**Art... check**

Which of the following is a convention Chinese artist Shen Zhou used in his brush paintings? He used only black ink to emphasize expressive brushstrokes. He painted several seated Buddha in the background. He painted flat, realistic figures to reflect strength and calmness. He...
*November 15, 2014*

**Physics**

Ohhhh, I was using the radius of the moon as the r instead of the arc length… I feel dumb haha Thank you, Greatly appreciated!!
*November 13, 2014*

**Physics**

The diameter of the Moon is 3.78x10^6m. It subtends an angle of .00982 radians at the surface of Earth. How far is the Moon from Earth? (Please explain I can't wrap my head around this question.)
*November 13, 2014*

**7th grade math**

consider the inequality 2x+3≤-3. Find the set of all integer solutions of this inequality that are also solutions of the inequality 5x-2<3. Please help I am really confuded
*October 22, 2014*

**math**

semir, sarah and sung so decided to raise money for a local homeless shelter by working in a local deli. the deli agreed to donate to the shelter a portion of the profits from each meal the three sold. semir sold 3 times as many meals as sarah. sung sold 2 more meals than ...
*October 14, 2014*

**Science/chemisty**

Explain in detail how to prepare 250. mL of a 0.125 M glucose solution. The formula for glucose is C6H12O6.
*October 13, 2014*

**Physics **

A horizontal force, F1 = 85 N, and a force, F2 = 18.4 N acting at an angle of θ to the horizontal, are applied to a block of mass m = 2.1 kg. The coefficient of kinetic friction between the block and the surface is μk = 0.2. The block is moving to the right. A. Solve...
*October 9, 2014*

**Trig**

Two people decide to find the height of an obelisk. They position themselves 25 feet apart in line with, and on the same side of, the obelisk. If they find that the angles of elevation from the ground where they are standing to the top of the obelisk are 65 degrees and 44 ...
*September 10, 2014*

**Chemistry**

Fannie eats a dozen doughnuts every 36 hours. How many doughnut does she eat in a week? I used Dimensional Analysis(which isn't helping at all), but it keeps giving me weird number, like 36 over 2016 or 252 over 2016.
*September 1, 2014*

**Maths**

Thanks for all the help, really appreciate it.
*August 28, 2014*

**Maths**

A circular lily pond is surrounded by a gravel walkway that is 4 m wide. Calculate the area of the walkway if the pond is 12 m in diameter.
*August 28, 2014*

**Math**

A number whose digit in the ten billions place is 5 less than 8
*June 18, 2014*

**Math**

:'(
*May 23, 2014*

**Math**

What are the solutions of the system? y = x2 + 3x – 4 y = 2x + 2 Don't understand
*May 23, 2014*

**Chemistry**

The fluoride ion concentration in a saturated solution of magnesium fluoride, MgF2, is 2.3 10-3 M. Calculate the value for the equilibrium constant.
*May 5, 2014*

**Chemistry**

Aniline, C6H5NH2, is a weak base. If the hydroxide ion concentration of a 0.201 M solution is 9.2 10-6 M, what is the ionization constant for the base?
*May 5, 2014*

**Chemistry**

Ah got it now thank you!
*May 1, 2014*

**Chemistry**

Where does the 6.4 come from? 0.784 = 5 over x then you divide 0.784 by 5? I don't quite understand sorry!
*May 1, 2014*

**Chemistry**

Calculate the grams of NaNO3 required to produce 5L of oxygen at STP if the percent yield of the reaction is 78.4%?
*May 1, 2014*

**Chemistry**

I am very confused. I tried several practice problems and am not getting them correct.
*March 26, 2014*

**Chemistry**

What is the mass if solute dissolved in the indicated volume of each of the following solutions? (b) 4.25 L of 0.450 M KIO4g (c) 60.0 mL of 0.310 M ZnSO4g (d) 60.0 mL of 0.310 M Ni(NO3)2g
*March 26, 2014*

**Chemistry**

A hospital saline solution is analyzed to confirm its concentration. A 60.0 mL sample with a mass of 50.443 g is evaporated to dryness. (a) If the solid sodium chloride residue has a mass of 0.413 g, find the mass/mass percent concentration of the NaCl solution. % (b) Find the...
*March 26, 2014*

**Linear Algebra**

I need help please!! How many solutions does the system of equations have? 2x=-10y+6 and x+5y=3 a. one b. two c. infinitely many d. none y=4x+3 and y=4x+4 a. one b. two c. infinitely many d. none x-4y=12 and y=1/4x-3 a. one b. two c. infinitely many d. none
*March 13, 2014*

**Chemistry **

Ik this has been answered, but doesn't the copper oxide have something to do with it? And could you explain it in simpler terms? I'm just confused because you said forget the copper oxide, but your using it somehow, what puzzles me is the carbon dioxide, because the ...
*February 23, 2014*

**Science**

Copper Oxide + Carbon -> Copper + Carbon Dioxide Calculate the mass of carbon needed to obtain 63.5g of copper from 79.5g of Copper Oxide
*February 23, 2014*

**Science**

Copper Oxide + Carbon -> Copper + Carbon Dioxide Calculate the mass of carbon needed to obtain 63.5g of copper from 79.5g of Copper Oxide
*February 23, 2014*

**physics**

A 475 gram box is given a push and it then slides up and back down a ramp with a 35.0° incline. The coefficient of friction is 0.30. (a) Determine the rate of deceleration as the box slides up the ramp. (b) Determine the rate of acceleration as the box slides back down ...
*February 20, 2014*

**Physics **

Find the net force and the acceleration for the situation below. 30N 20N <---------------[ 5.1kg]---------->
*February 19, 2014*

**Chemistry**

This answer is not correct
*February 14, 2014*

**Chemistry**

A sample of oxygen gas occupies 500.0 mL at -185°C and 75.0 cmHg. Calculate the temperature in °C if the gas has a volume of 221.0 mL at a 55.0 cmHg.
*February 14, 2014*

**Chemistry**

A sample of gas has a volume of 1.30 L at STP. What is the temperature in °C if the volume is 13.0 L at 2.00 atm?
*February 14, 2014*

**chemistry**

If the surface area of a human body is 16,700 square centimeters, what is the total weight of the atmosphere on a human body expressed in pounds?
*February 13, 2014*

**chemistry**

Calculate the final Celsius temperature of sulfur dioxide if 0.500 L of the gas at 35°C and 650 mmHg is heated until the pressure reaches 742 mmHg. Assume the volume remains 0.500 L.
*February 13, 2014*

**Ap chem**

Thanks
*February 12, 2014*

**Ap chem**

Why does pf3 have dipole dipole internolecular forces? I thought it had dispersion...
*February 12, 2014*

**algebra**

Mike needs at least a 75% average to pass his math course. The class contains 5 exams that are equally weighted. If he scored a 64%, 86%, 71%, and a 90% on the first 4 exams, what score does he need on the final exam to earn at least a 75% in the class?
*February 2, 2014*

**Algebra**

Martin sold his computer and software for $900.00, receiving three times as much for the computer then the software. What was the selling price of the computer and software?
*February 2, 2014*

**Chemistry**

N2(g) + O2(g) → N2O5(g) What volume of oxygen gas reacts to yield 750.0 cm3 of N2O5? The reaction conditions are 350°C and 2.50 atm pressure. 2N2 + 5 O2 = 2N2O5 I balanced correctly. What is my next step to solve this problem. I am confused and I want to understand ...
*February 2, 2014*

**Chemistry**

N2(g) + O2(g) → N2O5(g) What volume of oxygen gas reacts to yield 750.0 cm3 of N2O5? The reaction conditions are 350°C and 2.50 atm pressure. I balanced the equation 2N2+2O2 = 2N2O5 BUT I AM NOT GETTING THE CORRECT ANSWER, WHAT AM I DOING WRONG?
*February 2, 2014*

**Chemistry**

N2(g) + O2(g) → N2O5(g) What volume of oxygen gas reacts to yield 750.0 cm3 of N2O5? The reaction conditions are 350°C and 2.50 atm pressure. I balanced the equation 2N2+2O2 = 2N2O5 BUT I AM NOT GETTING THE CORRECT ANSWER, WHAT AM I DOING WRONG?
*February 2, 2014*

**Chemistry**

N2(g) + O2(g) → N2O5(g) What volume of oxygen gas reacts to yield 750.0 cm3 of N2O5? The reaction conditions are 350°C and 2.50 atm pressure
*February 2, 2014*

**Chemistry**

SO2(g) + O2(g) → SO3(g) What volume of sulfur dioxide gas reacts with 15.0 L of O2? The reaction conditions are 875°C and 1.00 atm pressure
*February 2, 2014*

**algebra**

The perimeter of a pool is 64 feet and has a width of x and a length of x-4. What is both the width and length of the pool?
*January 24, 2014*

**math**

19 cars start a race. in how many ways can the top 3 cars finish
*December 14, 2013*

**physics**

A small coin is inside a bowl. The bowl is a surface of revolution of the curve y=100x^4 m^-3. This coin slides around the inside of the bowl at a constant height of y=0.01 m above the bottom of the bowl. What is its angular velocity in rad/s? Accel due to gravity = 9.8 m/s^2
*June 24, 2013*

**please hurry**

what is the square root of 0.31428 with explanation.by divison method.
*May 20, 2013*

**Calculus**

Find the derivative
*May 1, 2013*

**Calculus**

f(x)= e−(5x)⋅cos(3x)
*May 1, 2013*

**calculus**

find the solution: (y^(2) dx)/(1-x)=dy
*April 11, 2013*

**calculus**

find the solution: e^y=1/(y^'+1)
*April 11, 2013*

**calculus**

Find the specified coordinates of the centroid of the area bounded by a) x=3 and 2x=y^2 find the coordinates x and y of the centroid b) y= x^3 and y=4x in the first quadrant. Find the x coordinate of the centroid
*April 11, 2013*

**calculus**

Find the coordinates of the centroid of the following volume of revolution formed by rotating the area bounded by y^2-4=-x^2, x=0,x=1, And the "x" axis about the "x" axis.
*April 11, 2013*

**calculus**

Find the particular solution of the following differential equation by using the given boundary conditions. y(1+x)=x(y+1)(dy/dx) when y=1 x=1
*April 11, 2013*

**calculus**

Find the centroid of 4 particles of equal mass located at (0,0), (4,2), (3,-5), and (-2,-3)
*April 11, 2013*

**Math**

please help!!!!Apply newtons method to approximate the x-values of the indicated points of intersection of the 2 graphs. continue the process until 2 successive approximations differ by less than 0.001. (Hint: Let h(x)=f(x)-g(x)) f(x)=x^6 g(x)=cos(x) 1)x= ??? (smaller value) 2...
*April 5, 2013*

**chemistry**

enthalpy change^H is +23kJ mol-1 of phosphine (PH3) for the reaction 2P(s)red+3H2(g)---->2PH3(g) a) Calc. entropy change for this reaction. Explain how this information allows you to determine the spontaneity or non-spontaneity of this reaction at any temp (S for PH3 is ...
*February 12, 2013*

**chemistry**

a gas sample heated in a cylinder uses 650kJ of heat. a piston that compresses this gas does 800kJ of work. What is the change in internal energy, ^E of the gas during this process?
*February 12, 2013*

**chemistry**

list the following substances in order of increasing molar entropy at 25'c. H2O(l), H2O(g), H2O(s), C(s), Ar (g) Explain your reasoning
*February 12, 2013*

**chemistry**

the standard free energies of formation of SO2(g) and SO3(g) are -300.4 and -370.4kJ mol-1 respectively. Calculate the value of the equilibrium constant at 25'C for the reaction 2SO2(g)+O2(g)==>2SO3(g)
*February 12, 2013*

**writing**

I need help to write a summery for the open univercity please write for me one Thanks
*February 7, 2013*

**science**

Which is the higher density of polyethylene, linear or branched? Select the choice with the best accompanying explanation
*January 12, 2013*

**science**

A pressure vessel contains a large volume of CO2 gas at 10 atm pressure. A membrane composed of a poly(ether ketone) polymer with thickness 100 microns and net effective area of 100 cm2 covers a small perforated port in the container. The solubility of CO2 at 10 atm is 6.97 x ...
*January 12, 2013*

**science**

What is the degree of polymerization, n, of polypropylene with a molecular weight of 600,000 g/mole?
*January 12, 2013*

**science**

Calculate the surface energy of the (100) surface of niobium. The enthalpy of atomization of niobium is 745 kJ/mole. Express your answer in units of J/cm2.
*January 12, 2013*

**science**

What is the pH of 50 mL of a 0.2M glycolic acid aqueous solution after adding 5 mL of 0.25 M KOH? The pKa of glycolic acis is 3.83 at 25 .
*January 12, 2013*

**science**

Estimate the Cl-As-F bond angle
*January 12, 2013*

**TO: MS SUE MATH 9**

ok :)
*December 13, 2012*

**TO: MS SUE MATH 9**

thank you for trying and hopefully its right :)
*December 13, 2012*

**TO: MS SUE MATH 9**

The cube of the sum of 5 an 2 is decreased by the square of the product of 6 and 4. Write an expression that models this statement. Then , solve. THANX
*December 13, 2012*

**Math 9 pleese help me thanx**

The cube of the sum of 5 an 2 is decreased by the square of the product of 6 and 4. Write an expression that models this statement. Then , solve.
*December 13, 2012*

**Physics**

A force of 40 N is required to start a 5 kg box moving across a horizontal concrete floor. (a) What is the coefficient of static friction between the box and the floor? (b) If the 40 N force continues, the box accelerates at 0.70 m/s2. What is the coefficient of kinetic friction?
*December 4, 2012*

**AP chemistry**

Liquid butane, C4H10, is stored in cylinders, to be used as a fuel. The normal boiling point of butane is listed as -0.5 C. (a) suppose the tank is standing in the sun and reaches a temperature of 35 C. Would you expect the pressure in the tank to be greater or less than ...
*October 28, 2012*

**ap chemistry help!!!!**

Ive been absent from class because of the flu so i don't have a clue how to figure these out! Help! due tomorrow at 12! 1).Suppose that 135 g of ethanol at 23◦C is mixed with 255 g of ethanol at 75◦C at constant atmospheric pressure in a thermally insulated ...
*October 24, 2012*

**Math**

Which coins would you use to make $0.28? Write two ways
*October 1, 2012*

**Math**

Write the number that is 2 tens more than 53.
*October 1, 2012*

**physics**

200 gram cube is moved by a 100 gram water filled Styrofoam cup
*September 20, 2012*

**Math **

A pet store has 15 rabbits and 25 cats. How many more cats than rabbits does the store have?
*September 19, 2012*

**Math**

Write a4-digit number that has a hundrens digit of 6, a tens digit of 3, and 9 for each of the other digits.
*September 19, 2012*

**college calc**

Give a formula for the function illustrated using a vertical shift of an exponential function. The two points marked on the graph are A=(−1,17) and B=(1,2). The red horizontal line is given by y=1, and is a horizontal asymptote of the function. What is the equation?
*September 6, 2012*

**math**

y = x2 + 6x
*July 26, 2012*

**math HELP HELP HELP**

Hi, I am 12 years experienced tutor and assignment helper for computer science. I am ready to get this assignment done for you but you have to pay fee for it.For further discussion email me at hardeepsp ( at the rate) gmail (dot)com or contact me in skype or gtalk. my skype is...
*April 30, 2012*

**Programming logic**

Hi, I am 12 years experienced tutor and assignment helper for computer science. I am ready to get this assignment done for you but you have to pay fee for it.For further discussion email me at hardeepsp ( at the rate) gmail (dot)com or contact me in skype or gtalk. my skype is...
*April 30, 2012*