Tuesday

February 28, 2017
Total # Posts: 1,627

**Chemistry**

Pu-238 is radioactive by alpha-decay (half-life 87.7 y). Each decay releases 5.6 MeV of energy. Pu-238 is sometimes used to power space probes. If all the decay energy can be converted to electric power, what mass of Pu-238 would be required to power a 22 kW space probe for at...

*October 15, 2013*

**Chemistry**

write out the balanced equation when Iron(II) sulfate, potassium permanganate, and sulfuric acid react to form Iron (III) sulfate, manganese (II) sulfate, Potassium sulfate, and water.

*October 14, 2013*

**Chemistry**

Using atomic masses, If a certain batch of D2O has a purity of 99.75 weight %, what is its purity in atom (actually molecule) %

*October 3, 2013*

**Algebra Emergency!!**

Thank you guys the help is great

*October 2, 2013*

**Algebra Emergency!!**

Find the inverse of f(x)=2x+1/x-1 and please VERIFY(CHECK) Thanks so much

*October 2, 2013*

**Algebra Emergency**

and the verification?

*October 2, 2013*

**Algebra Emergency**

Find the inverse of 2/2x-1 and verify.

*October 2, 2013*

**Chemistry**

The isotopic abundance of naturally occurring hydrogen is as follows: 1H 99.985 atom % 2H 0.015 atom% When H2 gas is formed from naturally occurring hydrogen, what percentages of the molecules have molecular weights of approximately 2, 3 and 4?

*October 1, 2013*

**Algebra**

Two persons, A and B, together have $6 less than a third person, C. If B gives $5 to A, then A will have half as much money as c does. If A gives $5 to B, then A will have one third of what c has. How many dollars has each?

*September 29, 2013*

**calculus**

integrating e^1/3dx i got 3e1/3 +c pls am i right

*September 6, 2013*

**Please help Physical pharmacy**

How does KH2PO4 induce controlled flocculation?

*September 4, 2013*

**Please help Physical pharmacy**

How does KH2PO4 induce controlled flocullation?

*September 3, 2013*

**home economics**

Explian craft

*August 12, 2013*

**Science**

Can anyone balance Sn 2+ to Sn4+ in basic solution as half reaction

*July 20, 2013*

**Elementary mechanics**

Given that the mass and radius of jupiter are respectively 190000000kg 7150000km.Calculate the escape velocity from the surface of the planet(a)11.2 km/s(b)33.3km/s(c)59.5km/s(d)110.4km/s

*July 15, 2013*

**Elementary mechanics**

what is common to the variation in the range and the hieght of a projectile. I'm thinking of horizontal acceleration pls what do u think

*July 15, 2013*

**Elementary mechanics**

A force of 2i+7jN acts on a body of mass 5kg for 10 seconds. The body was initally moving with constant velocity of i-2jm/s.Find the final velocity of the body in m/s, in vector form. (a)5i+12j(b)12i-5j(c)10i-7j(d)7i+10j

*July 14, 2013*

**maths**

(Q1)a+3b+2c=3,2a-b-3c=-8,5a+2b+c=9.solve for a,b&c by matrix method. (a)2,9,3(b)4,(-3),1(c)7,5,5(d)3,(-4),7 (Q2)a+2b+3c=5,3a-b+2c=8,4a-6b-4c=2.find a,b&c by Guassian method.(a)1,4,9(b)4,(-5),5(c)5,(-3),9(d)(-1),5,10

*July 5, 2013*

**ENHANCING CHILDREN'S SELF ESTEEM**

I am doing a teacher aide course online and I need you to correct my answers for me

*June 19, 2013*

**Chemistry**

636 grams of Na2CO3(s) are disolved in 3.0 liters of aqueous solution

*June 14, 2013*

**Chemistry**

For the cell diagram Pt(s)|H2(g)|H+(aq)||Cu2+(aq)|Cu(s) Write a balanced equation for the half-reaction at the cathode. The cathode is the site of reduction so copper gets reduced. So wouldn't the answer be: Cu2+(aq) -> Cu(s) + 2e-?

*June 11, 2013*

**science**

ferrous sulphate + sodium hydroxide forms ppt. ferrous hydroxide + sodium sulphate is left in the solution write a balanced chemical eqn.. for this..

*June 11, 2013*

**statistics**

a study found 37% of a new technique resulted in pregnancy and in that technique 25% resulted in multiple births what is the probabilty that the new technique produced a pregnacy and multiple births what is probability that a random selected pregnancy did not produce multiple ...

*June 6, 2013*

**calculus 2**

Test the series for convergence/divergence. The Summation from n=1 to infinity of: 1*3*5...(2n-1)/(2*5*8...(3n-1) I'm not sure what to do with the extra terms on the left.

*June 5, 2013*

**Math**

Subtract 750 grams from 3 kilograms

*May 29, 2013*

**teacher aide**

according to carl jung what are the two main ways people process information

*May 26, 2013*

**Science (2nd Try)**

To determine the boing point of a liquid, a student heats 10 mL of the liquid in a test tube and records the temperature every minute for 20 minutes. In this example, time is the what? The choices are: Independent variable dependent variable hypothesis control Is it dependent ...

*May 23, 2013*

**Science**

To determine the boing point of a liquid, a student heats 10 mL of the liquid in a test tube and records the temperature every minute for 20 minutes. In this example, time is the what? The choices are: Independent variable dependent variable hypothesis control Is it dependent ...

*May 22, 2013*

**Math**

The scooter does 40km to a litre of petrol. If I use 7.25l how far did the scooter travel

*May 21, 2013*

**Physics**

A circular plate of radius 0.5 m is placed perpendicular to the direction of the magnetic field of 0.5 Tesla. What is the change of flux in the plate if it rotates and its plane becomes parallel to the direction of the magnetic field?

*May 17, 2013*

**alg**

sqrt(3x^2)=-18 check:

*May 16, 2013*

**8need a function rh grade math**

a 154 lb person burns 420 calories per hr riding an exercise bike at 15 mph. Need a function rule to represent the total calories burned over time.

*May 14, 2013*

**math (2nd Try)**

A salesman gets paid on commission, and his commission is based on how many units he sells during the month. If the salesman sells $1500 worth of units or less, he makes a flat commission of $900 plus 10% of the sale. If he sells more than $1500 worth of units, he makes an ...

*May 13, 2013*

**math**

New photo imaging techniques on computers allow artists to distort an image from its original shape. Figure 1 is a square image (X x X). Figure 2 is stretched 4 units wider and shrunk 4 units shorter than figure 1. (x+4)(X-4). How many square units greater is the area of ...

*May 10, 2013*

**math**

A ball is kicked from ground level into the air. Its height, y, in feet after x seconds can be represented by the equation y=40x - 16x^2. What is the total elapsed time, in seconds, from the time the ball is kicked until it reaches ground level again? I used the quadratic ...

*May 10, 2013*

**math**

Solve for the variable h: 5r - 6h = m Is it h = 5/6m +r If not, please explain. Thanks

*May 10, 2013*

**math**

What is the result when correctly solving the formula for the variable w when the formula for the perimeter P of a rectangle is P=2l + 2w? Is it w = (p-2l)/2 If not, please explain. Thanks

*May 10, 2013*

**math**

Ursula spent a total of $52.34 on two new outfits. She bought two shirt for $12.99, a pair of pants for $18.50, and a skirt. If the sales tax was 7.5%, what was the cost of the skirt? Please solve and exlain. Thanks

*May 10, 2013*

**math**

A salesman gets paid on commission, and his commission is based on how many units he sells during the month. If the salesman sells $1500 worth of units or less, he makes a flat commission of $900 plus 10% of the sale. If he sells more than $1500 worth of units, he makes an ...

*May 10, 2013*

**Alg 1**

Solve for the variable h: 5r - 6h = m Is h=5/6m +r Correct?

*May 9, 2013*

**Alg 1**

The formula for the perimeter P of a rectangle is P=2l +2w. What is the result when correctly solving the formula for the variable w?

*May 9, 2013*

**Alg 1**

Issa is driving to the airport to catch a flight to miami, and her arrival depoends on traffic. If the traffic is light, then she can drive 60 mph and arrive at the airport 1 hour early. If traffic is heavy, she can drive 35 mph and arrive at the airport on time. The equation ...

*May 9, 2013*

**Algebra 1**

Emily rows six miles downstream in 1 hour and her friend Ashley,rowing 1 mile per hour faster,completes the return trip in 2 hours. 1.Find the speed of the current(c) and each girls rowing speed. 2.If Emily and Ashley were rowing separately,who would complete their trip first ...

*May 7, 2013*

**statistics**

-.044

*May 6, 2013*

**Physics**

a magnetic rail gun is constucted to give a space vehicle its intial launch velocity, thereby reducing the amount of fuel the vehicle has to carry. it consist of two very long parallel rails across which is positioned a large current carrying crossbar 7.65 m long. The crossbar...

*May 4, 2013*

**Math**

Use Excel’s PMT function to calculate the monthly mortgage payment

*May 2, 2013*

**math**

Alyssa is enrolled in a public-speaking class. Each week she is required to give a speech of greater length than the speech she gave the week before. The table below show the length of several of her speeches: WK #/Length of Speech (seconds) 3/150, 4/180, 5/210, 6/240 If this ...

*April 29, 2013*

**Alg 1**

Diana is driving 182 miles to Orlando for a math convention. She has already driven x miles of th trip. If Diana drives below 70 miles per hour for the remainder of th trip, which inequality best represents the amount of time in hours, t, that is will take her to complete the ...

*April 29, 2013*

**algebra**

1=radical3-3p-2p

*April 29, 2013*

**physics**

what pressure (in atm) would be exerted by 76g of fluorine gas in a 1.5 litre vessel at -37 degrees Celsius?

*April 26, 2013*

**Algebra**

What is the maxima and minima of a parobola?

*April 22, 2013*

**Math**

Ms Perez owns 2 properties in different towns. The 1st property is assessed at $125,000 and has a tax rate of $6.35 per 1000 dollars. The 2nd property has the same assessed value, but is taxed at the rate of $0.00587 per dollar. Derive the solution to the total tax obligation ...

*April 19, 2013*

**Probability**

If 5 juniors and 4 seniors apply for a job at a school which has 2 openings, what is the probability that 1 junior and 1 senior will be randomly chosen for the job.

*April 19, 2013*

**Alg 1**

If y = 1, then (x + 5) times y = x + 5 Which property does it apply to? Cumutative Property of addition? My choices are: Inverse Property of Mult. Identity Property of Mult. Associative Property of addition Cummutative Property of addition.

*April 16, 2013*

**Alg 1**

Michael takes 90 min to type 5850 words. If he increases his typing speed by 5 words/min. How many minutes will he take to type 10,500 words? Is it 150 minutes?

*April 16, 2013*

**Alg 1**

It is copied correctly. My choices are: 6/5 sqrt11 + 6/5 5/6 sqrt11 + 6/5 6/5 sqrt11 - 6/5 5/6 sqrt11 - 6/5

*April 16, 2013*

**Alg 1**

Solve the proportion: 4/x = (radical sign over 11, not -1) 11 - 1/3 Please solve and explain. My answer does not match any of my choices.

*April 16, 2013*

**Alg 1**

Why multiply it by 200? My answer choices are: 18.07 ft 35.96 ft 9.04 ft 71.93 ft

*April 16, 2013*

**Alg 1**

Landon is standing in a hole that is 6.5 ft deep. He throws a rock and it goes up into the air, out of the hole, and then lands on the ground above. The path of the rock can be modeled by the equation y = -0.005x^2 + 0.45x - 6.5, where x is the horizontal distance of the rock...

*April 16, 2013*

**alg 1**

Thanks Steve, you are always so helpful. There was no error data. The only thing I did not type from the problem was: (The measurements are accurate to the nearest inch). This was typed over the answer choices.

*April 16, 2013*

**alg 1**

Find the percent error in calculating the volume of the prism. V=(bw)(h) v=11 x 8 (7) V=616 my choices were: 19% 10% 119% 83% I'm not sure what it means to find the percent error. Please explain. Thanks.

*April 16, 2013*

**Alg 1**

What are the approximate solutions of 2x^2 -x + 10 = 0 In working this, I came up with a negative (-79) under the radical sign. Can I take the sq rt of a negative? my choices are: -2, 2.5 -1.97, 2.47 -2.5, 2 No solution I think it is no solution. Is this correct? If not, ...

*April 15, 2013*

**Alg 1**

Reasoning: The equation 3x^2 + bx + 3 = 0 has one real solution. What must be true about b? I think it is: b must be the same as -4(a)(c). What are your thoughts?

*April 15, 2013*

**Alg 1**

The equation is: -w^2 +75w - 1200 the neg sign was so close to the = sign above. Sorry about that.

*April 15, 2013*

**Alg 1**

The quadratic formula and the discriminat. The daily production of a company is modeled by the function p=-w^2 + 75w - 1200. The daily production, p, is dependent on the number of workers w, present. If the break-even point is when p=0, what are the least and greatest number ...

*April 15, 2013*

**Alg 1**

A box shaped like a rectangular prism has a height of 17 in. and a volume of 2720 in^3. The length is 4 inches greater than twice the width. What is the width of the box? Please solve and explain what I need to do. The choices are: -10 8 20 40

*April 14, 2013*

**Alg 1**

The rectangular has an area of 5400 cm^2. What is the value of w? 5400 = (w)(2w - 30) 5400 = 2w^2 - 30 w 5400 = 2w(w - 15) Now I am stuck. My choices are: -45 cm 45 cm 60 cm 90 cm What do I need to do next to get the correct answer? Thanks.

*April 14, 2013*

**Alg 1**

Completing the square: Which of the following is a solution x^2 + 14x + 112 = 0? If necessary round to the nearest hundredth. x= -0.24 x= -4.24 x= 4.24 no solution I worked it and got neither of the answers. I got x= 0.9 and x=-14.9. Where did I go wrong? Thanks

*April 14, 2013*

**Alg 1**

Completing the square: Find the value of c such that each expression is a perfect-square trinomial. p^2 - 11p + c Is the answer 30.25? If not, please explain. Thanks

*April 13, 2013*

**Alg 1**

That two consecutive numbers that multiply and equal 42 is 6x7. 6 + 1+7

*April 13, 2013*

**Alg 1**

The product of two consecutive integers, n and n+1, is 42. What is the positive integer that satisfies the situation? Is it 6 x 7?

*April 13, 2013*

**Alg 1**

A triangular-shaped wall has a base of 2x+4 and a height of x+3. The area of the triangle is 56 in^2. What is the value of "x"?

*April 13, 2013*

**Al**

Factoring to solve quadratic equations: Find the value of x as it relates to the triangle. Area = 600 cm^2 There is a large triangle that is divided by a 90 degree angle in the middle. That 90 degree angle line is "x" and the complete bottom of the large triangle is...

*April 13, 2013*

**PHYSICS**

Bricks have a thickness of 12 cm, if an external wall of the house measures 10 mx 15m, calculate the rate of heat exchange through this wall if the inside temperature is 200C and the outside temperature is 50C.

*April 10, 2013*

**Alg 1**

Factoring to solve quadratic equations: Use the Zero-Product Property to solve each equation. Write your solution in roster form: The volume of a storage tub shaped like a rectangular prism is 24 ft^3. The height of the tub is 3 feet. The width is w feet and the length is w+...

*April 8, 2013*

**Alg 1**

The length of a rectangular prism is four times the width. The height of the prism is 8 ft. If the volume of the prism is 160 ft^3, what is the width of the prism? Round to the nearest tenth of a foot. Please solve and explain. Thanks

*April 6, 2013*

**Alg 1**

Solving quadratic equations: What is the value of "b" in the triangle where one part of the right angle is "3b" and the other part of the right angle is "b". The area inside is 24 in^2. Please solve and explain. Thanks

*April 6, 2013*

**Alg 1**

Solving quadratic equations: What is the radius of the largest circular quilt that can be made with an area less than or equal to 70 ft^2? Round your answer to the nearest tenth of a foot if necessary. Please solve and explain. Thanks

*April 6, 2013*

**science**

What may be some long-term effects of human interactions with the oceanic environments?

*April 5, 2013*

**math**

The square yard you are mowing has an area of 9600 ft^2. What is the side length of the yard? Round your answer to the nearest tenth of a foot if necessary. Please solve and explain

*April 5, 2013*

**Chem HW!! Difficult! HELP!**

Urea (H2NCONH2) is used extensively as a nitrogen source in fertilizers. It is produced commercially from the reaction of ammonia and carbon dioxide. 2 NH3(g) + CO2(g) ---Heat pressure---> H2NCONH2(s) + H2O(g) Ammonia gas at 223°C and 90. atm flows into a reactor at a ...

*April 5, 2013*

**Alg 1**

A baseball player hit a ball with an upward velocity of 46 ft/s. Its height h is feet after t seconds is given by the function h = -16t^2 + 46t + 6. What is the maximum height the ball reaches? How long will it take the baseball to reach the maximum height? How long does it ...

*April 4, 2013*

**alg 1**

Quadratic graphs and their properties: Identify the domain and range of each function: y = 4x^2 - 3 I have no idea how to find the range and domain. Would you please explain in detail how I can determine the domain and range in the quadratic problems?

*April 4, 2013*

**STAT**

A population has a standard deviation ó of 23 units. (Give your answers correct to two decimal places.) (a) Find the standard error for the mean if n = 11. (b) Find the standard error for the mean if n = 41. (c) Find the standard error for the mean if n = 85.

*April 3, 2013*

**math**

A diagram shows the design of the 12 in quilt (12" x 12") block that a quilter is sewing. What are the dimensions of each triangle in the quilt block? What are the dimensions of each triangle to the nearest tenth of an inch?

*April 3, 2013*

**Alg 1**

A golden rectangle is 32 cm long. The ratio of length to width is (1 + sq rt 5)/2. What is the width of the rectangle in simplest radical form? Please solve and explain. Thanks.

*April 3, 2013*

**Alg 1**

Find the exact solution for each equaton. Find the approximate solution to the nearest tenth. 3 sq rt 3/sq rt 1 + sq rt 1 = x/sq rt 3 Please solve and explain. Thanks

*April 3, 2013*

**math**

Operations with radical expressions: Simplify each quotient. -3/sq rt 2 + sq rt 5

*April 3, 2013*

**Alg 1**

Find the exact solution for each equation. Find the approximate solution to the nearest tenth. 5 sq rt 2/ sq rt 2 -1 = x / sq rt 2 Please explain in detail how to work this. I am really confused. Thanks

*April 3, 2013*

**Alg 1**

Operations with radical expressions: Simplify each quotient 7/sq rt 2 - sq rt 3 Please solve and explain how you did it. What do you do when the denominator is a negative?

*April 3, 2013*

**Alg 1**

An area rug is shaped like a golden rectangle. Its length is 8 ft. What is the rug's width? Write your answer in simplified radical form and rounded to the nearest tenth of a foot. Please explain how to work this. Thanks.

*April 2, 2013*

**Alg 1**

Thanks you all so much!

*April 2, 2013*

**Alg 1**

Would you please show me how you arrived at the answer "D." I don't know how to set up the problem to get the answer. Thanks

*April 2, 2013*

**Alg 1**

Simplifying Radicals A gardener is mowing a 20-yd-by-40 yd rectangular pasture using a diagonal pattern. He mows from one corner of the pasture to the cxorner diagonally opposite. What is the length of this pass with the mower? Give your answer in simplified form. My answer ...

*April 2, 2013*

**math**

A gardener is mowing a 20 yard-by-40 yd rectangular pasture using a diagonal pattern. He mows from one corner of the pasture to the corner diagonally opposite. What is the length of this pass with the mower? Give your answer in simplified form. Please explain to me how to ...

*April 2, 2013*

**math**

A walking path is shaped like a rectangle with a width 7 times its length "l". What is a simplified expression for the distance between opposite corners of the walking path?

*April 2, 2013*

**math**

A carpenter is building rectangular walls for a room addition. The width of a section of wall is two times the height h. Each section has a brace that connects two opposite corners of the section. What is a simplified expression for the length of a brace?

*April 2, 2013*

**Math**

Pythagorean Theorem A rectanglar box is 9 in. wide, 11 in. tall, and 20 in. long. What is the diameter of the smallest circular opening through which the box will fit? If necessary, round to the nearest tenth of a centimeter.

*April 1, 2013*

**Social Studies**

PLEASE EXPLAIN IN YOUR OWN WORDS PLEASE PLEASE HELP IN YOUR OWN WORDS PLEASE. :( :( 1) Explain the similarities and differences between corporate farms and mixed-crop farms. 2) Identify two problems resulting from urban sprawl in the western region of the United States. If ...

*March 28, 2013*

**chemistry**

Phosphoric acid is a triprotic acid with the following pKa values: pKa1=2.148 pKa2=7.198 pKa3=12.375 You wish to prepare 1.000 L of a 0.0200 M phosphate buffer at pH 7.11. To do this, you choose to use mix the two salt forms involved in the second ionization, NaH2PO4 and ...

*March 28, 2013*