Tuesday

October 21, 2014

October 21, 2014

Total # Posts: 113

**chemistry**

5.00g aluminum sulfide and 10.0g water react according to the reaction: Al2S3 + 6 H2O -> 2 Al(OH)3 + 3 H2S What is maximum mass of H2S that can be formed? What mass of excess reactant remains when the reaction is complete?
*October 12, 2014*

**math**

if a gardener fences in the total rectangular area shown in the illustration instead of just the square area,he will need twice as much fencing to enclose the garden.how much fencing will he need ?
*September 26, 2013*

**Biology**

What role does the environment play in convergent evolution?
*November 20, 2012*

**Biology**

Yes, but it has to be about evolution in general, not just humans.
*November 17, 2012*

**Biology**

Describe the changes you'll see (evolution wise) if you were granted 1 million years of life.
*November 17, 2012*

**Biology**

Describe the changes you'll see (evolution wise) if you were granted 1 million years of life.
*November 17, 2012*

**personl finance**

Bill Mason is considering two job offers. Job 1 pays a salary of $43,300 with $5,310 of nontaxable employee benefits. Job 2 pays a salary of $40,500 and $6,380 of nontaxable benefits. Use a 20 percent tax rate.
*June 13, 2012*

**Physics! plese help**

A 1320-N uniform beam is attached to a vertical wall at one end and is supported by a cable at the other end. A 1960-N crate hangs from the far end of the beam. Using the data shown in the figure, find (a) the magnitude of the tension in the wire and the magnitudes of the (b) ...
*June 7, 2012*

**Physics**

Some bacteria are propelled by motors that spin hair-like flagella. A typical bacterial motor turning at a constant angular velocity has a radius of 1.9x10-8m, and a tangential speed at the rim of 2.5x10-5 m/s. (a) What is the angular speed (the magnitude of the angular ...
*June 7, 2012*

**PLEASE HELP ME!!!**

CAN YOU HELP ME PLEASE UNRGENTLY NEEDED.THANKS FOR HELPING ME TO GET SOME ANSWERS FOR THIS QUESTION BELOW. 1. SOME VALLEYS WERE NOT ERODED BY THE RIVERS FLOWING IN THEM.VALLEYS CAN BE FORMED BY FAULTING AND GLACIAL EROSION. WHAT FEATURES COULD YOU LOOK FOR WITH IN VALLEYS TO ...
*April 25, 2012*

**Calculus-derivatives**

Determine h'(x) for h(x)= [x/(1-x)]^2
*February 20, 2012*

**Calculus**

Which of the following is a point at which the tangent to y=(x-2)^2(x+3) is horizontal? a) (-2,16) b) (-1, 18) c) (1,4) d) (2,0) I found the derivative of y=(x-2)^2(x+3) which is 3x^2-2x-8 if I solved for 0, it wouldn't give me the answer that are listed above. What did I ...
*February 19, 2012*

**Calculus**

So y2-y1=m(x2-x1) y-(-2)=-6(x-(-1) y=6x-1 therefore the slope of tangent is 6?
*February 19, 2012*

**Calculus**

Determine the slope of the tangent to the curve y=2(x^2+x-1)^3 at (-1, -2)
*February 19, 2012*

**Calculus**

Determine the coordinates of the point(s) on the graph of y=3x- 1/x at which the slope of the tangent is 7. So the derivative of y=3x- 1/x is y'=3 + 1/x^2 What do I do next?
*February 18, 2012*

**Math**

How many horizontal tangents does the graph of f(x)=(x-1)^2(x-3)^2 have? f(x)=(x-1)^2(x-3)^2 =2(x-1)(1)+2(x-3)(1) =2x-2+2x-6 f'(x)=4x-8 0=4x-8 =4(x-2) x=2 Therefore it only has 1 horizontal tangents?
*February 18, 2012*

**Physics**

How long does it take a plane, traveling at a speed of 170 m/s, to fly once around a circle whose radius is 3500 m?
*October 30, 2011*

**Physics**

I'm in this class too :/ For this problem, you have to use both equations F=Ma and F=(mv^2)/r Step 1: solve for F using F=Ma 5.70kg x 9.81 m/s^2 = 55.917 N Step 2: plug this into the other equation 55.917N = (2.40kg x v^2)/0.500m (55.917N x .5m)/2.40kg =11.65 m^2/s^2 (...
*September 30, 2011*

**algebra**

how do you use the substitution method to solve x + y =2 y = -2x
*April 29, 2011*

**math: pre calculus**

How do I find the exact value of sec(2.4)?
*March 9, 2011*

**algebra**

One side of a rectangle is 12 inches, and the other side is x inches.What values of x will make the perimeter at most 44 inches?
*February 3, 2011*

**Personal Finance**

During a job interview, Pam Thompson is offered a salary of $50,000. The company gives annual raises of 12 percent. What would be Pam’s salary during her fifth year on the job?
*January 29, 2011*

**biology**

how is it possible for an enzyne to lower the required energy of activation for a reaction.
*December 14, 2010*

**chemistry**

How many moles of antifreeze (a molecular substance) must be added per liter of water to protect the cooling system of a motocar to -30 degrees F.
*December 14, 2010*

**Kinesiology**

Joey weighs 77 lb and sits on a seesaw at a distance of 30 inches from the fulcrum. Jenny weighs 67 lb and sits on the opposite side of the seesaw at a distance of 48 inches from the fulcrum. Mikey weighs 30 lb and wants to play but doesn’t know where to sit in order to ...
*December 5, 2010*

**11th grade**

so I have this problem and I dont know what numbers to multiple and whatnot. Can someone help me? This is the problem: 4000 g Fe2O3* 1mole Fe2O3/159.68 gFe2O3* 3mole CO2/1mole Fe2O3
*December 2, 2010*

**pre-calculus**

2y^-3 = 4e^(-x/2)/(1+e(-x/2)) my teacher gave this problem in my chem class and i dont know what he is really asking , does any one have an idea if i have to solve for y or what's going on.. how would this be done..
*September 20, 2010*

**Chemistry!!**

42.8 divided by 181 equals 0.236
*May 21, 2010*

**science**

Can you help me balance some equations? I tried and failed several times... 1. calcium hydroxide + phosphoric acid yield calcium phosphate + water 2. copper + sulfuric acid yield copper(II) Sulfate + water + sulfur dioxide 3. hydrogen + nitrogen monoxide yield water + nitrogen...
*November 10, 2009*

**physics**

A particle is released on the smooth inside wall of a cylindrical tank at A with a velocity v which makes an angle beta with the horizontal tangent. When the particle reaches a point B a distance h below A, determine the expression for the angle theta made by its velocity with...
*November 7, 2009*

**Cost Accounting**

Katherine Company's Sales Budget Has The Following Unit Sales Projection For Each Quarter Of The Calendar Year 2009. January -March 540,000 April-June 680,000 July-September 490,000 October-December 550,000 Total 2,260,000 Sales for the first quarter of 2010 are expected ...
*November 7, 2009*

**physics**

i see where you went wrong. you have 7.5E6 and the second radius and it's supposed to be 7.0E6. yeah that's how i worked the problem. i converted my answer wrong when i went from m/s to km/h thank you for your help!
*November 6, 2009*

**physics**

Upon its return voyage from a space mission, the spacecraft has a velocity of 24000km/h at point A, which is 7000km from the center of the earth. Determine the velocity of the spacecraft when it reaches point B, which is 6500km from the center of the earth. The trajectory ...
*November 6, 2009*

**Cost Accounting**

PLEASE, PLEASE, can you give me the step to calculate these: 1.Prepare the beginning inventory for the first quarter 2.Prepare the budgeted beginning inventory for the second - fourth quarters 3.Prepare the budgeted production for each quarter 4.Prepare the budgeted production...
*November 5, 2009*

**management accounting**

Fi a company has a policy of maintaining an inventory of finished goods equal to 30 percent of the following month's sales. For the forthcoming month of March, Ball has budgeted the beginning inventory at 30,000 units and the ending inventory at 33,000 units. This suggests...
*November 4, 2009*

**physics**

The 60kg collar slides on the curved rod in the vertical plane with negligable friction under the action of constant force F in the cord guided by the small pulley at D. If the collar is released from rest at A, determine the force F which will result in the collar striking ...
*October 31, 2009*

**physics**

sorry the angle theta is measured below the radius to the vertical
*October 31, 2009*

**physics**

A small bead of mass m is carried by a circular hoop of radius r which rotates about a fixed vertical axis. Show how one might determine the angular speed w of the hoop by observing the angle theta which locates the bead. Theta is measured to the right of the vertical axis. ...
*October 31, 2009*

**Physics**

Block A has a mass of 20kg and is placed on top of cart B which has a mass of 100 kg. Blosk A has a pulley attatched to it with a force of P acting towards the right. Cart B is on rollers. The coefficient of kinetic and static friction are both the same value of 0.5. Find the ...
*October 23, 2009*

**Physics**

thanks! i was multiplying by 0.82 instead of dividing
*October 18, 2009*

**Physics**

A 120-V motor has mechanical power output of 2.00 hp. It is 82.0% efficient in converting power that it takes in by electrical transmission into mechanical power. (a) Find the current in the motor (b) Find the energy delivered to the motor by electrical transmission in 3.30 h ...
*October 18, 2009*

**physics**

In the design of a control mechanism, the vertical slotted guide is moving with a constant velocity x'= 15in/s during the interval of motion from x= -8in to x= +8in. For the instant when x= 6in calculate teh n- and t-components of acceleration of the pin P, which is ...
*October 11, 2009*

**geometry**

How are the radii of 2 two concentric circles related to the distance between them? I tried making an equation using their cirmcumferences but I was way off. All I did was subtract the inner circle's circumference from the outer circle's circumference and set it equal ...
*October 11, 2009*

**physics**

wait it would be different. wouldn't you just subtract 15 since it's starting from an angle with 15 less degrees?
*October 10, 2009*

**physics**

would beta be different for part b?
*October 10, 2009*

**physics**

A meteor P is tracked by a radar observatory on the earth at O. When the meteor is directly overhead (theta = 90), the following observations are recorded: r = 80km, r'= -20km/s, and theta'= 0.4rad/s. (a) Determine the speed of hte meteor and the angle, beta, which it...
*October 10, 2009*

**physics**

thank you so much! this really helped me see where i went wrong
*October 9, 2009*

**physics**

A test car starts out from rest on a horizontal circular track of 80m radius and increases it's speed at a uniform rate to reach 27.78 m/s in 10s. Find the magnitude of the total acceleration of the car 8s after the start. Ok so I know that the total acceleration is the ...
*October 9, 2009*

**Physics**

I see how this would be correct but the book says the answer is 11.81ft/s and the vertical rise is 2.16 ft
*October 4, 2009*

**physics**

yes i measured s0 from point A so it's 0
*October 4, 2009*

**physics**

A car is traveling at a constant initial velocity of 100km/h on a level portion of road. It encounters a 6 percent incline (tan(theta)= 6/100) at point A and the car decelerates at a constant rate of gsin(theta). Find the speed of the car (a) 10 seconds after passing point A ...
*October 4, 2009*

**3rd grade**

my dauter have a math problem and I dont no how to help her. this is the question: estimate each diffirence using compatible numbers for exc. 53-24=30 the next is 346-78=? we don`t now the answer thank you.Jessi
*October 1, 2009*

**Alegebra 1**

can someone please help me asap with this two problems I'm really stuck here. 1) solve for j if b=j+v/2 2) 9r+9s+9
*September 21, 2009*

**physics**

yeah the coefficient of static friction is 0.5 and coeffient of kinetic friction is 0.4. theta is measured below the horizontal
*September 13, 2009*

**physics**

A block sits against a vertical wall and a 120 lb force P acts diagonally to the left on the block at an angle below the horizontal. Determine the magnitude and direction of the friction force which the vertical wall exerts on the 100 lb block if theta is (a)15 degrees (b)30 ...
*September 13, 2009*

**Geometry**

can someone please help me with this question I'm in really need with this question
*September 13, 2009*

**Geometry**

I need help asap please Which figure above, if any, is topologically equivalent to the given figure? Identify the topologically equivalent figure by letter. A pretzel a.pencil b.pipe, c.trophy
*September 13, 2009*

**physics**

this still isn't the correct answer though. my book says that it's 0.204
*September 13, 2009*

**physics**

Each of the four wheels of the vehicle weighs 40 lb and is mounted on a 4in diameter journal. The total weight of the vehicle is 960 lb, including wheels, and is distributed equally on all four wheels. If a force P = 16 lb is required to keep the vehicle rolling at a constant ...
*September 13, 2009*

**Alegebra**

So the answer for #1 is 1/35 is that I have to do for that problem though?
*September 11, 2009*

**Alegebra**

Ok so I really need help with problem 1 I have no clue
*September 11, 2009*

**Alegebra**

#3 I got this answer (20000*.7)-(3000*.3) =14000-900 =$13,100. expected profit Is this right
*September 11, 2009*

**Alegebra**

this is what i got from the 2nd problem of the total 7 digits in the number he knows the first 5 that leaves 2 for him to find out with 0 not being the last number so he knows 10 possible for the 6th and 9 possible for the 7th (not 0) 10 * 9 = 90 possible numbers then it takes...
*September 11, 2009*

**Alegebra**

Can some one please help me with this 3 problems I have a hard time with probabilities I'm studying for my mid-term. Thank you 1) Urn A has balls numbered 1 through 7. Urn B has balls numbered 1 through 5. A ball is selected at random from urn A and then a ball is selected...
*September 11, 2009*

**physics**

thank you so much! it's really clear now with the way you've explained it
*August 23, 2009*

**physics**

A cylinder that has a 40.0 cm radius and is 50.0 cm deep is filled with air at 20.0°C and 1.00 atm. A 21.0 kg piston is now lowered into the cylinder, compressing the air trapped inside. Finally, a 79.0 kg man stands on the piston, further compressing the air, which ...
*August 23, 2009*

**physics**

A block of unknown mass is attached to a spring with a spring constant of 6.00 N/m and undergoes simple harmonic motion with an amplitude of 12.0 cm. When the block is halfway between its equilibrium position and the end point, its speed is measured to be 33.0 cm/s a)Calculate...
*April 27, 2009*

**Chemistry**

How many grams of NaCL are required to make 250ml of a 0.4M solution?
*April 21, 2009*

**Chemistry**

There are 200 mmoles NaOH/400ml. What is the molarity of the solution?
*April 21, 2009*

**Chemistry**

M=6/600=0.01M?
*April 21, 2009*

**Chemistry**

If you had 6 moles in a 600ml of solution, what would be the molarity?
*April 21, 2009*

**Chemistry**

What weight of NaOH would be required to prepare 3000ml of a 2.5M solution?
*April 21, 2009*

**Chemistry**

What is the molarity of a solution prepared by diluting 100g of NaH2PO4 to 1L?
*April 21, 2009*

**Calculus**

Use the dot product to show that the line c = by + ax is perpendicular to vector v = <a,b> They seem like they would be parallel. doesn't c also = <a,b>?
*April 15, 2009*

**Chemistry**

How would you prepare 100 ml of 0.9% w/v saline?
*April 14, 2009*

**Chemistry**

Describe how you would prepare 500 ml of a solution that is 40% bleach solution by volume.
*April 14, 2009*

**Chemistry**

2000/100=150/x =7.5 ml?
*April 14, 2009*

**Chemistry**

How many milliliters of a 2000.0 mg/dl stock solution are needed to prepare 100.0 ml of a 150.0 mg/dl working solution?
*April 14, 2009*

**Chemistry**

A 2% solution of Hydrochloric acid is required for a procedure. A 5% solution is availabe. How much of the 5% solution will be required to make 1 L of solution?
*April 14, 2009*

**Chemistry**

How would you prepare 100 ml of 0.9% w/v saline?
*April 14, 2009*

**Chemistry**

Describe how you would prepare 500 ml of a solution that is 40% bleach solution by volume.
*April 14, 2009*

**Chemistry**

How many milliliters of a 2000.0 mg/dl stock solution are needed to prepare 100.0 ml of a 150.0 mg/dl working solution?
*April 14, 2009*

**physics**

A mass m is attached to a cord passing through a small hole in a frictionless, horizontal surface. The mass is initially orbiting with speed vi in a circle of radius ri. The cord is then slowly pulled from below, and the radius of the circle decreases to r. (Use r_i for ri, ...
*April 6, 2009*

**physics**

A straight ladder is leaning against the wall of a house. The ladder has rails 4.50 m long, joined by rungs 4.800 m long. Its bottom end is on solid but sloping ground so that the top of the ladder is 3.400 m to the left of where it should be, and the ladder is unsafe to climb...
*March 30, 2009*

**Chemistry**

How many milliliters of glacial acetic acid are needed to prepare 2.0 L of 10.0% volume/volume acetic acid?
*March 25, 2009*

**Chemistry**

Last one. Describe how you would prepare 100ml of a solution that is 22% acetic acid by volume?
*March 24, 2009*

**Chemistry**

Last one. Describe how you would prepare 100ml of a solution that is 22% acetic acid by volume?
*March 24, 2009*

**Chemistry**

Last one. Describe how you would prepare 100ml of a solution that is 22% acetic acid by volume?
*March 24, 2009*

**Chemistry**

One liter of 70% alcohol is needed. How much 95% alcohol is required to make the 70% solution. And thank you for last question and any future ones.
*March 24, 2009*

**Chemistry**

One liter of 70% alcohol is needed. How much 95% alcohol is required to make the 70% solution. And thank you for last question and any future ones.
*March 24, 2009*

**Chemistry**

A 200 mg/dl solution was diluted 1:10. This diluted solution was then additionally diluted 1:5. What us the concentration of the final dilution?
*March 24, 2009*

**physics**

An 6.00 g bullet is fired into a 2.30 kg block initially at rest at the edge of a frictionless table of height 1.00 m. The bullet remains in the block, and after impact the block lands 2.00 m from the bottom of the table. Determine the initial speed of the bullet. I know that ...
*March 24, 2009*

**physics**

nevermind i figured it out
*March 22, 2009*

**physics**

how did you get that the velocity is sqrt(2gH)?
*March 22, 2009*

**physics**

Water falls without splashing at a rate of 0.220 L/s from a height of 2.20 m into a 0.720 kg bucket on a scale. If the bucket is originally empty, what does the scale read 3.20 s after water starts to accumulate in it? The answer is supposed to be in Newtons but I don't ...
*March 22, 2009*

**physics**

A loaded ore car has a mass of 935 kg and rolls on rails with negligible friction. It starts from rest and is pulled up a mine shaft by a cable connected to a winch. The shaft is inclined at 26.0° above the horizontal. The car accelerates uniformly to a speed of 2.20 m/s ...
*March 2, 2009*

**physics**

A block of mass 0.570 kg is pushed against a horizontal spring of negligible mass until the spring is compressed a distance x. The force constant of the spring is 450 N/m. When it is released, the block travels along a frictionless, horizontal surface to point B, the bottom of...
*March 2, 2009*

**Math**

Ms. Snyder wants to buy a television at an electronics store. All televisions at the store are 3/4 of the original price, p. She has a $40 discount coupon she will use during the sale. What equation should Ms. Snyder use to find the final price, f, of a television?
*February 25, 2009*

**Math**

How do you solve this: A 20-ounce bag of popcorn costs $2,80. If the unit price stays the same, how much does a 35-ounce bag of popcorn cost?
*February 25, 2009*

**physics**

A light spring with force constant 3.85 N/m is compressed by 5.00 cm as it is held between a 0.250 kg block on the left and a 0.500 kg block on the right, both resting on a horizontal surface. The spring exerts a force on each block, tending to push them apart. The blocks are ...
*February 24, 2009*