# Posts by albert

Total # Posts: 204

**Chemistry**

What should the molar concentrations of benzoic acid and sodium benzoate be in a solution that is buffered at a pH of 4.75 and has a freezing point of -2.0 ?C? (Assume complete dissociation of sodium benzoate and a density of 1.01 g/mL for the solution.)

**Specialist Mathematics**

Need help with three proofs. Proof#1: Prove that |x+y| is less than or equal to |x|+|y| Proof#2: Prove that |x|-|y| is less than or equal to |x-y| Proof#3: Prove that |x+y+z| is less than or equal to |x|+|y|+|z|.

**Physics**

Hello, I need some help with this physics problem. This was the only one I couldn't solve, and the teacher wouldn't help me because she wanted me to figure it out for myself, just like everyone else tried. (Although no one did) Here is the question: Type in imgur dot ...

**Math (calculus 3)**

A football is thrown down the field by a quarterback from a height of 1 foot with an initial velocity of 40 feet per second at angle of pi/6 radians. If a receiver catches the ball downfield at a height of 1 foot above ground; a) How long was the ball in the air? b) What was ...

**Math**

A very large book has pages numbered from 1 to 11521. How many times is the digit 3 printed?

**life orientation**

introductory paragraph why i chose human right

**Math**

A wheel makes6 1/12 revolution per minute. If it rotates 45 minutes,how many revolutions does it make

**science**

find the gravitational force exerted by the sun on a 70 kg man located at the earth's equator a)at noon when the man is closest to the sun. b)at midnight when he is futherst from the sun. c)calculate the diferrence in gravitational acceleration due to the sun between noon...

**trigonometry**

can someone help me prove the identities on this: 1- 1/2 sin2θ = sin^3θ + cos^3θ / sinθ + cosθ

**trigonometry**

sina^2θcos^2θ= 1/8 (1-cos4θ)

**Math**

B, right?

**Math**

When you solve the system shown by the elimination method, which statement is true? y + 3x = 10 −y − 3x = 10 A. You eliminate y; the sum of the coefficients of y is zero. Then, you can solve for x. B. There is no solution; x and y are eliminated and you get the ...

**Math**

Solve the system using substitution. 6x + y = 12 4x + 6y = −8 A. (2 1/2,3) B. (−2 1/2,−3) C. (2 1/2,−3) D. no solution I GOT B!

**Math**

Solve the system using substitution. x = y − 6 y = 6 − 3x A. (0, 6) B. (6, 0) C. (0, −6) D. (−6, 0)

**Math**

Solve the system using substitution. y = 4x − 5 y = 2x + 1 A. (−2, −3) B. (1, 3) C. (−2, −13) D. (3, 7)

**trigonometry**

from a point 3 m above the water surface, the angle of elevation of the top of a certain tree is 30°40', while the angle of depression of its image is 65°10'. Find the height of the tree and its distance from the point of observation.

**stat**

Forty-nine items are randomly selected from a population of 500 items. The sample mean is 40 and the sample standard deviation 9. Develop a 99% confidence interval for the population mean

**Finance**

Evans Technology has the following capital structure. Debt ............................................ 40% Common equity .......................... 60 The aftertax cost of debt is 6 percent, and the cost of common equity (in the form of retained earnings) is 13 percent. a)...

**Chemistry**

To what decimal place should each answer be rounded? and how many significant figures does the rounded answer have? a) 9cm + 2.8 cm= 11.8cm (unrounded) b) 0.135 atm + 0.6 atm= 0.735 atm (unrounded) PLEASE HELP

**math**

convert 40.0m^3 to liters. note that 1mL = 1cm^3. can you show me how to do this problem?

**Chem**

To what decimal place should each answer be rounded? and how many significant figures does the rounded answer have? a) 9cm + 2.8 cm= 11.8cm (unrounded) b) 0.135 atm + 0.6 atm= 0.735 atm (unrounded) can you show me how to do this?

**Algebra**

The number of items on two grocery list differs by seven.the total number of items is 33 how many items on each list

**Physics**

A train accelerates from the rest at the station A at a rate of 0.8 m/s2 for 25 s, the travels at constant velocity for 77.5 s before it comes to rest at the station B after period of retardation lasting 20 s. What is the distance between stations A and B, and the average ...

**math**

a metal cutter was accurate to the nearest micron.about how many pieces of metal 0.8188 centimeters long could the metal cutter cut from a 32.253 length of metal?

**physics**

A ball of mass M1 moves with a velocity U1, collides perfectly elastically with a stationary ball of mass M2 . After the collision, M1 and M2 move with velocities V1 and V2 respectively. Show that : V1 =(M1-M2) / (M1 + M2 ) * U1 .

**physics**

a) the earth exerts a force called gravitational force on every particle on its surface.. The force of gravity has a value of 9.8 or 10 meters per second square when approximated . Also weight is the product of the mass of the object by the downward force acting on it (...

**Physics**

A block initially at rest, slides down from the top of an inclined plane 30degrees above the horizontal. The plane is 100feet long and frictionless. what distance will it travel on a frictionless horizontal surface at the foot of the plane 6seconds after it has started from rest?

**english (3rd grade)**

2,4,5. Noun

**english(4th grade)**

7and8.Direcj object

**english(4th grade)**

I already know what infinitives are, but can anyone check my answers? Predicate noun Predicate noun direct object direct object direct object appositive Object of preposition predicate noun Subject appositive

**english(4th grade)**

Identify the infinitive and classify whether it is used as a subject, direct object, predicate noun, appositive, and object preposition. 1.Her only thought was to win. 2.My desire is to help. 3.Mrs. Cao loves to crochet. 4.They remember to say the ...

**english(4th grade)**

Thanks Ms.Sue

**english (4th grade )**

Identify the infinitive and classify whether it is used as a subject, direct object, predicate noun, appositive, and object preposition. 1.Her only thought was to win. 2.My desire is to help. 3.Mrs. Cao loves to crochet. 4.They remember to say the rosary last night. 5.The ...

**Chemistry**

I'm doing a redox potential/lead acid cell experiment and one of the questions that were asked was: -What were the identities of the gases you saw being produced at the + and - electrodes during the cell conditioning process? We used H2SO4 How do I go about answering this...

**Chemistry**

@DrBob222 thank you!

**Chemistry**

Please help me set up these problems. I have been staring at them for hours and I can't tell where I went wrong. Question: Consider the following reaction: CaCO3(s)→CaO(s)+CO2(g). Estimate ΔG∘ for this reaction at each of the following temperatures. (...

**AP CALC. AB**

E=MC^2

**physics**

Phisic

**Chemistry Physics**

so its setup like (20*1.00)*(90-50)+(20*1.00)*(90-50) = 1600g?

**Chemistry Physics**

How many grams of water at 20°C are necessary to change 800g of water at 90°C to 50°C?

**Math**

what you have to do is how many cm can go to a meters. which you use METER= cm/100.00

**TRIG WORD PROBLEMS**

from 25 feet away from the base of a building, the angle of elevation from the ground to the top of a building is measured 38 degrees. how tall is the building. WHat i did was put 25 feet on the base of the triangle the angle measurement oppsite and the longer leg x is this ...

**RIGHT TRIANGLE TRIG**

THAnk You DAMON

**RIGHT TRIANGLE TRIG**

a kite is being flown 150 yards of string. the kite has an angle of elevation with the ground 65 degrees. how high above the ground is the kite. I DON'T KNOW HOW TO SET UP THE PROBLEM

**theory of interest**

1.Two investments are made at the same time. The first consists of investing 1550 dollars at a nominal rate of interest of 7.9 percent convertible semiannually. The second consists of investing 1450 dollars at a nominal rate of interest of 7.9 percent convertible daily. How ...

**physics**

a turntable rotates about a fixed axis, making one revolution in 10s . the moment of inertia of the turntable about it's axis is 1200kg/m^2 . a man of mass 80kg , initially standing at the center of the turntable, runs out along a radius. what is the angular velocity of ...

**THEORY OF INTEREST**

Suppose that a money market fund pays a nominal rate of interest of 8.7 percent convertible monthly. What is the equivalent nominal rate convertible quarterly?

**Economics**

What are welfare payment or consumer?

**social studies**

From the point of an environmentalist, which is probably the most significant argument against offshore drilling for oil?

**chemistry**

- convert E for each half reaction into Delta G - add the Delta G values - convert back to E - answer is -0.744V

**Grammar**

"passages" is plural, hence the plural of the "is" verbs.

**Language Arts**

14. A 16. A

**English 12**

"… I felt much better."

**English art**

Please, critique this critique: Very dramatic interactions in a world novel to me, with canine preening for competitive exhibition, following the emotions of the lead characters is exciting. This is no "Dog story", and Lassie wouldn't be noticed in the wings. ...

**English**

Thank you.

**English**

What is parallelism, please?

**computer programming**

In what language, please?

**The language of Art**

What's the question, please?

**algebra**

Yes. The difference of their ages is the key.

**algebra**

A man and a woman's ages total 98. He is twice as old as she was when he was her age now. What are their ages?

**english**

pry, or coax — certainly not "delude"

**English**

Well, I don't know what "…test for his logic." means; but, none of the "senses" you mention are evident.

**English Language Arts**

Yes. Perhaps "blemish" would be a better choice.

**ENGLISH**

Por nada!

**physics**

A shotgun!

**History**

How Mali Build 0n Ghana Empire

**Math**

3/4x^2 x 2x^2y x 23xy^3

**Polynomials**

Can someone please help me get the sum difference and product of this problem I am so lost x^3+ 2x-5∶ x^4-x^3+ 3x^2- 2x+3

**finance**

Suppose you pay $1000 into a savings account that pays 2% per year, compounded annually. How many years will would it take for the money in the account to double, to $2000? use "successive approximation."

**science**

Wire

**physics**

Suppose the straight-line distance between New York and San Francisco is 4.4 106 m (neglecting the curvature of the earth). A UFO is flying between these two cities at a speed of 0.69c relative to the earth. What do the voyagers aboard the UFO measure for this distance?

**Chemistry**

How do you differentiate between fluorene and acetanilide? Suggest procedures and steps involved other than melting point and chromatography.

**Chemistry**

How do you distinguish between fluorene and acetanilide? Suggest methods other than melting point and chromatography.

**math**

During an art contest at your school, you and a classmate each won blue ribbons for 1/3 of the pieces you entered in the contest. You won 2 blue ribbons and your classmate won 3 blue ribbons. Explain how this could be.

**ACT Math**

Carlos goes to a local deli for lunch and orders a sandwich. He needs to choose a bread, a meat, a vegetable, a cheese and a source. How many sandwich combinations are possible? Assume Carlos always pick only one item from each category. Bread: Italian, Rye, Wheat, White and ...

**English Analysis**

Reading The Stranger by the lovely Albert Camus. Just need help understanding this question: -After I listed some themes I explored, my teacher asks: "Given the themes you listed, are any conventions questioned based on the treatment of a given theme? Describe how one or ...

**Algebra**

Please let me know if I answered these correctly. thank you, #2. Add: 3p^2 – 5p – 4 and 9p^2 + 10p – 2 A. 12p2 + 15p – 6 B. 12p2 + 5p – 2 C. 12p2 + 5p – 6 D. 12p2 + 15p – 2 answer D ________________________ #7. (3x^2 – 2x – 1)(x^2...

**algebra**

You would add up all the numbers in the survey, then subtract that number by the number of people surveyed to get your answer.

**Implicit differentiation calculus**

ok so the final answer would b a) y' = -(y + 5x^4y^2 + 9x^2)/(x+2x^5y) and b) y' = -y sin x thank you SO much once again steve, my exam is in a couple of hours and this solution really helped me, im very thankful. thanks so much!!

**Implicit differentiation calculus**

thank for you so much steve!!! i just wanted to double check.. for (a) it is y' = - (y+5x^4y^2+9x^2)/(x+2x^5y) i was wondering if the last part of it (x+2x^5y) is it 2x^(5y) or 2x^5(y). im not sure if the "y" is in the exponent or not.

**Implicit differentiation calculus**

PLEASE HELP , I DON'T UNDERSTAND find dy/dx by implicit differentiation a) xy + x^5y^2 + 3x^3 - 4 = 1 b) lny = cos x thank you

**Calculus grade 12**

thank you for taking your time to answer my questions steve!

**Calculus grade 12**

find the slope of the tangent line to y^4 = 3x^2 - 2x at the point (1,1)

**Calculus grade 12**

hi, is that all for a? please let me know, thank you Maya

**Calculus grade 12**

find dy/dx by implicit differentiation a) xy + x^5y^2 + 3x^3 - 4 = 1 b) lny = cos x thank you

**Calculus grade 12**

hi i need help differentiating these.. 1. y = cos(3x^2 + 2x) 2. y = ln(3x^2 + 5) thank you

**English**

2 and 3

**math**

$24 lft a 15 percent tip how much total

**chemistry**

Can someone pleeeeeaaase explain Charle's law in a simple way.

**trig**

1.Ifg(x)=cos4x,find g'(pie/24). 2.Differentiate y=csc^2 pie*x

**Chemistry**

Dichromate is Cr2O7 so

**college physics**

calculate the specific heat of 200g of substance whose temperature is 30 degree celcius if it is mixed with 200g of water heated in a 300g iron container at 100 degree celcius. the final temperature of the mixture is 98 degree celcius.

**college physics**

calculate the specific heat of 200g of substance whose temperature is 30 degree celcius if it is mixed with 200g of water heated in a 300g iron container at 100 degree celcius. the final temperature of the mixture is 98 degree celcius.

**college physics**

what is the force applied in the direction of the wire at a point attached to the patient in a traction system if the mass applied ius equal to 5kg.?

**College Algebra**

A rectangle field with area of 1,500,000 needs to be fenced. 2W+2L=5,000. solve for L and W

**Chemistry**

when 25.0 mL of a solution containing both Fe2+ and Fe3+ ions is titrated with 23.0 mL of 0.0200 M KMnO4 (in dilute sulfuric acid). As a result, all of the Fe2+ ions are oxidized to Fe3+ ions. Next, the solution is treated with Zn metal to convert all of the Fe3+ ions to Fe2+ ...

**Chemistry**

calculate the energy associated with a photon whose wavelength is 14.5*10^-8cm.

**accounting**

What generally accepted Accounting Principle(s) dominate the issue of asset valuation?

**macroeconomics**

70 90 100 110 125

**math**

Estimate products of fractions. 2/9x26