Saturday

October 10, 2015
Total # Posts: 858

**Physics**

Water flows at a speed of 15 m/s through a pipe that has a radius of 0.40 m. The water then flows through a smaller pipe at a speed of 45 m/s. What is the radius of the smaller pipe?
*December 19, 2011*

**physics**

A light spring of constant k = 156 N/m rests vertically on the bottom of a large beaker of water (Fig. P9.34a). A 4.10 kg block of wood (density = 650 kg/m3) is connected to the spring and the block-spring system is allowed to come to static equilibrium (Fig. P9.34b). What is...
*December 15, 2011*

**chemistry**

A 15.0 ml sample of an unknown HClO4 solution requires 50.3 ml if 0.101 M NaOH for complete neutralization. What was the concentration of the unknown HClO4 solution? The neutralization reaction is: HClO4(aq)+ NaOh(aq)yields H2O(l)+ NaClO4 (aq) If anyone can help me to set this...
*December 3, 2011*

**Chem**

A gas generator is constructed to collect the CO2(g) evolved from a reaction. during lab we set up the CO2 generator by placing 10ml of 3 M HCL in a 200mm test tube. then slide the 75mm test tube into the 200mm test tube without splashing any of the acid into the sample. The ...
*November 16, 2011*

**calculus**

ahh thank you so much
*November 8, 2011*

**calculus**

So from a previous post I asked, "f(x)=(1+x) what is f'(x) when x=0?" and someone replied, "the derivative of f(x)=x+1 is f'(x)=1 so your answer would just be 1" Now my question is why!? it doesn't matter what x is? f'x when x=238423904 will...
*November 8, 2011*

**Math Garde 3**

2x9 and 5x9 will always be even numbers? I think that's what they're after.
*November 8, 2011*

**Spanish**

Correction 1.A nosotros les duele la cabeza.
*November 7, 2011*

**Spanish**

I had to write sentencesabout an ache in a certain body part with indirect pronoun . There were pictures provided and the first part of the sentence like "A mi amigo" and we had to fill in the restCould you check, please 1. pain in head A nosotros nos duele la cabeza...
*November 7, 2011*

**Spanish**

Please check-I have to rewrite with an indirect object pronoun 1. Escribo una carta a mi abuela. Le escribo una carta a mi abuela. 2.Mando una tarjeta postal a mis amigos. Les mando una tarjeta postal a mi amigos.
*November 7, 2011*

**calculus**

so it doesn't matter what x is? f'x when x=238423904 will also be 1? For some reason I thought that you would have to plug in 0 for x.. like f(x) = (1+x) and when x = 0, f(0) = (1+0) = 1. So f'(0) would = 0. Can anybody help me rationalize why this is wrong? thanks...
*November 3, 2011*

**calculus**

f(x)=(1+x) what is f'(x) when x=0
*November 3, 2011*

**physics**

A 42-kg pole vaulter running at 14 m/s vaults over the bar. Her speed when she is above the bar is 1.7 m/s. Neglect air resistance, as well as any energy absorbed by the pole, and determine her altitude as she crosses the bar.
*October 12, 2011*

**physics**

A model rocket is launched straight upward with an initial speed of 45.4 m/s. It accelerates with a constant upward acceleration of 2.98 m/s 2 until its engines stop at an altitude of 150 m. What is the maximum height reached by the rocket? The acceleration of gravity is 9.81 ...
*October 3, 2011*

**calculus**

lim as approaches infinity of sin(pie.x/2-3x) i need the work and answer find the limit
*October 2, 2011*

**physics**

How long is the rocket in the air? Answer in units of s
*October 2, 2011*

**physics**

When does the rocket reach maximum height? Answer in units of s
*October 2, 2011*

**physics**

How long is the rocket in the air? Answer in units of s
*October 2, 2011*

**physics**

When does the rocket reach maximum height? Answer in units of s
*October 2, 2011*

**physics**

A model rocket is launched straight upward with an initial speed of 45.4 m/s. It accelerates with a constant upward acceleration of 2.98 m/s 2 until its engines stop at an altitude of 150 m. What is the maximum height reached by the rocket? The acceleration of gravity is 9.81 ...
*October 2, 2011*

**physics**

A helicopter is rising at 5.2 m/s when a bag of its cargo is dropped. The bag falls for 2.5 s. what is the bags velocity
*September 19, 2011*

**Math**

how do i approach this problem though so i can get the right answer
*September 15, 2011*

**Math**

If C represents a variable, then which of these expressions has a coefficient of 3 ? a) C + 3 (b) 3 C + 1 (c) 2 C − 3 (d) 5 − 2 C (e) 3 − 2 C
*September 15, 2011*

**Math**

Its decimal i believe cause fractional notations are converted into decimal notations
*September 15, 2011*

**Chemistry**

Ejected neutrons sustain the fission reaction by serving as reactants to split additional fissionable nuclei, which roduce additional neutrons, which can slit additional dissionable nuclei, and so on. The result is a what???
*September 13, 2011*

**Mr. bobpursley**

Thank you for your time and frankness. I agree with you.
*September 4, 2011*

**chemistry f/u**

Thank you Mr. bobpursley. I am still unclear on a few things. massethanol*Ceth(Tf-7.7)+masswater*Cwater*(Tf-27.1)=0 solve for Tf 17.75g ethanol x(Tf-7.7)+31.6g water x (Tf-27.1)=0 This is the algebra that I do not know how to derive to move to the next step. Do I add it all to...
*September 4, 2011*

**Chemistry**

New problem. Any assistance is greatly appreciated. 22.5 ml of ethanol (density=0.789 g/ml) initially at 7.7 deg. C is mixed with 31.6 ml of water (density=1.0 g/ml) initially at 27.1 deg. C in an insulated beaker. Assuming that no heat is lost, what is the final temperature ...
*September 4, 2011*

**Chemistry**

New problem. Any assistance is greatly appreciated. 22.5 ml of ethanol (density=0.789 g/ml) initially at 7.7 deg. C is mixed with 31.6 ml of water (density=1.0 g/ml) initially at 27.1 deg. C in an insulated beaker. Assuming that no heat is lost, what is the final temperature ...
*September 4, 2011*

**Dr. Bob**

Thank you kind sir for guiding my work on the last question. You gave me the means to answer the question correctly without giving me the answer. Your expertise is greatly appreciated. If you tutor online, I would gladly pay for your guidance if you are interested
*September 4, 2011*

**Chemistry**

Thank you very much for your assistance preemptively. My question has to do with law of conservation of mass. A 50g sample of iron reacts with 21g of oxygen to from how many grams of iron oxide? Is the answer maybe 71g or 29g. This is stumping me.
*September 3, 2011*

**chemistry**

This has to do with law of conservation of mass I believe but it stumps me. 50g or iron reacts with 21g of oxygen to form how many gram of iron oxide? Is the answer 71g or 29g
*September 3, 2011*

**Pre-Calc**

Find [4(cos115+isin115)]^6
*July 25, 2011*

**calculus**

Why did the 2ðx^2+108/x^2 become 2ðx-108/x^2
*July 18, 2011*

**calculus**

A large soup can is to be designed so that the can will hold 54pi cubic inches of soup. The radius of the can is "x" inches and the height of the can is "h" inches. Find the values for the radius and the height such that the amount of metal needed is as ...
*July 18, 2011*

**MATH**

1) During the two months of the summer holiday, you find a summer job that pays $160 per week with a $10 a week raise. How much money will be made by the end of the summer? 2 Your grandmother offers you $1 on the first day of March break and offers to double it each day of the...
*July 8, 2011*

**derivative **

Find the derivative. 11) f(t)=(1)/(sqrt(8t-3)) 12) g(t)= ((4t-3)^2)/ ((5t+1)^4) Thanks.
*June 15, 2011*

**calculus**

18) The demand equation is x + 1/6p - 10+0. Compute the elasticity of demand and determine whether the demand is elastic, unitary, or inelastic at p=50. a) 5; elastic b) 1/9; inelastic c) 7/6; elastic d) 6; elastic I choose answer A. Is that correct?
*June 15, 2011*

**maths**

The mean weight (1.0042kg) of the contents of samples of 30 bags of sugar has standard error 0.008kg. Choose the option that is closest to the probability, to three decimal places, that the mean weight of the contents of samples of 30 bags of sugar will be 1kg or more. Options...
*June 13, 2011*

**maths**

The mean weight (1.0042kg) of the contents of samples of 30 bags of sugar has standard error 0.008kg. Choose the option that is closest to the probability, to three decimal places, that the mean weight of the contents of samples of 30 bags of sugar will be 1kg or more. Options...
*June 12, 2011*

**maths**

The mean weight (1.0042kg) of the contents of samples of 30 bags of sugar has standard error 0.008kg. Choose the option that is closest to the probability, to three decimal places, that the mean weight of the contents of samples of 30 bags of sugar will be 1kg or more. Options...
*June 11, 2011*

**physics**

i need a mathematical relationship between density and height
*June 9, 2011*

**Algebra 2 **

Find the distance between the points (12, 8) and (4, 2). 100 units 14 units 10 units –10 units Find the midpoint of the points (3, 1) and (7, –5). (1, 6) (2, 1) (2, –3) (5, –2) Find the vertex and focus of the parabola whose equation is 4y = x2 + 4. V(0, 4...
*June 4, 2011*

**Algebra 2 **

1. Find the midpoint and the distance between the points (8,–6) and (13, 4). 1. (4, –3), 10 units 2. 3. 4. (10, –1), 9 units 2. Find the vertex and the focus of the parabola with the equation 4y = x2 – 12x + 52. 1. V(6, 4), F(6, 5) 2. V(6, 4), F(7, 4) 3. V(...
*June 4, 2011*

**MathHelp**

The fare for riding in a taxi is a $3 fixed charge and $0.80 per mile. The fare for a ride of d miles is $6.75. Write an equation that could be used to find d.
*May 26, 2011*

**Algebra**

Par Manufacturing manufactures steel rods. Suppose the rods ordered by a customer are manufactured to a specification of 0.5 in. and are acceptable only if they are within the tolerance limits of 0.49 in. and 0.51 in. Letting x denote the diameter of a rod, write an inequality...
*May 26, 2011*

**math**

well for the first one i'm pretty sure it is a parabola, and i'm confused on how you would find the vertex focus and directrix
*May 19, 2011*

**math**

how would you solve these equations? y^2+2y-2x+5=0 and (x^2/16)-(y+1)^2/(25)=1 thank you!
*May 19, 2011*

**science**

Whats a good reason for dissecting a heart and what would be the purpose?
*May 12, 2011*

**chemistry**

given 14g silver oxide, how much silver can be made?
*May 9, 2011*

**stats**

use technology to find the P-value for a two tailed test with n=28 and a test statistic t=2.032 P-value =???? Help please! i dont understand this
*May 8, 2011*

**math**

Thanks. So no matter what the times I have to subtract the starting time from the ending time - right?
*May 5, 2011*

**math**

if a game is started at 7:48am and finishes at 10:58am ... how do I figure how many hours and minutes it took to finish the game?
*May 5, 2011*

**Statistics**

A certian company enjoyed 3.5% profits in year 1 over its revenue in Year 0. In Year 2, it enjoyed 5.75% profits over Year 1. In Year 3, it posted 1.25% profits over Year 2. What single, constant profit over this period of years would have produced the same profit? The teacher...
*May 3, 2011*

**physics**

A particular guitar string is supposed to vibrate at 192 Hz, but it is measured to actually vibrate at 212 Hz. By what percent should the tension in the string be changed to get the frequency to the correct value?
*May 1, 2011*

**Chemistry HELP!!**

A sample of nicotine weighing 0.3204 g was vaporized in a flask with a volume of 487 mL. This sample exrted pressure of 74.3 mm Hg at 20 degrees C. What is the molar mass of nicotine? I know this has to do with N=P*V/R*T. and 1 atm=760 mm Hg. Please help and show work. ...
*April 28, 2011*

**Chemistry**

so then would i take: .284 L/44 g/mol =.006 then .006*100 g/mol =.645 then take .645/1.506 = .429 ---->.429 * 100 = 42.9% is this how i would get the answer?
*April 28, 2011*

**Chemistry**

a sample of limestone and other solid materials is heated and the limestone decomposes to give calcium oxide and carbon dioxide: CaCO3 ----> CaO + CO2 a 1.506 g sample of limestone containing material produces 284 mL of CO2 at STP. what is the mass percent os CaCO3 in the ...
*April 28, 2011*

**Chemistry**

A sample of nicotine weighing 0.3204 g was vaporized in a flask with a volume of 487 mL. This sample exrted pressure of 74.3 mm Hg at 20 degrees C. What is the molar mass of nicotine? I know this has to do with N=P*V/R*T. and 1 atm=760 mm Hg. Please help and show work. ...
*April 28, 2011*

**Chemistry DrBob**

I don't understand how you get the answer. I really don't understand any of this, how do I set it up with the numbers? once i get how to do this, then i feel i will understand how to set these up from here on out. so if you could, show all your work, thanks (A). A ...
*April 27, 2011*

**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*

**chemistry**

a reaction witha 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.
*April 27, 2011*

**chemistry**

a reaction witha 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.
*April 27, 2011*

**math**

what would be the length of a shadow cast by a 50 foot high building?
*April 26, 2011*

**Physics**

Looks like your screwed
*April 14, 2011*

**Algebra 1**

How do you graph the function: y = 6x(squared) - 12x + 1 Then, how would you find the Axis of Symmetry and the Vertex? Any help is greatly appreciated
*April 14, 2011*

**calculus**

Please help. I need ( with details) how to differentiate with the chain rule f(x)=(x^2-6x+23)^3/2. I need to
*April 10, 2011*

**Com155**

So sorry. I am not good at english class thats why I am asking for help.
*April 4, 2011*

**Com155**

Sorry I wrote it wrong. The list is adjectives. I am having trouble finding the other adverb.
*April 4, 2011*

**Com155**

I think the adverbs are live, teenage, family, becoming, providing and world's. I cant figure out the other adjective.
*April 4, 2011*

**Com155**

Are they family and accidentally
*April 4, 2011*

**Com155**

Could you please help me locate the adjectives and adverbs in the below paragraph? ”Blending state of the art animation with live action, Hop is a comedy about E.B., the teenage son of the Easter Bunny. On the eve of taking over the family business, E.B. leaves for ...
*April 4, 2011*

**Chemistry**

508 cm fly
*March 28, 2011*

**MATH**

A yard stick/ruler would probably be a good choice. Measuring tape perhaps.
*March 27, 2011*

**Physics**

A particle with a mass of 2.0×10−5 kg and a charge of +2.0 microC is released in a (parallel plate) uniform horizontal electric field of 13 N/C. If the plates are 5.6 cm on each side, how much charge is on each? (in pC) From what I have so far, the formula E=(4piKQ...
*March 27, 2011*

**physics**

I think you forgot to include the actual question part...
*March 27, 2011*

**Physics**

I whole-heartedly agree!
*March 26, 2011*

**Physics**

Two charges, -2.0 micro C and -6.0 micro C, are located at (-0.65 m, 0) and (0.65 m, 0), respectively. There is a point on the x-axis between the two charges where the electric field is zero. Find the location of the point where the electric field is zero.
*March 26, 2011*

**chemistry**

Name the following compounds (with absolute configurations) and are they enantiomers, diastereomers or structure isomers or no relation at all? img34.imageshack.us/i/namethese.jpg/ i think they are disteromers and their names are 1] 1S, 2S - (2-bromo - 3,4 - dimethyl pentane) ...
*March 17, 2011*

**chemistry**

Write down the reaction between 1-pentyne and 2 molar HBr should it be 2 br or 4 br? img718.imageshack.us/i/triple2.jpg/
*March 14, 2011*

**chemistry**

i posted this already but i got the answer for someone elses question. the pka of acetone is CH3COCH3 is 19.3 which of these bases is strong enough to deprotonate acetone? a)KOH (pka of H20 = 15.7) b)Na+ -C(triplebond)CH (pka of C2H2 = 25) c)NaHCO3 (pka of H2CO3 = 6.4) d)...
*March 14, 2011*

**chemistry**

i posted this already but i got the answer for someone elses question. the pka of acetone is CH3COCH3 is 19.3 which of these bases is strong enough to deprotonate acetone? a)KOH (pka of H20 = 15.7) b)Na+ -C(triplebond)CH (pka of C2H2 = 25) c)NaHCO3 (pka of H2CO3 = 6.4) d)...
*March 12, 2011*

**Chemistry**

the pka of acetone is CH3COCH3 is 19.3 which of these bases is strong enough to deprotonate acetone? a)KOH (pka of H20 = 15.7) b)Na+ -C(triplebond)CH (pka of C2H2 = 25) c)NaHCO3 (pka of H2CO3 = 6.4) d)NaOCH3 pka of CH3OH = 15.6) i know the answer is b but why is it b? is it ...
*March 12, 2011*

**AP Chemistry**

There is an unknown amount of unlabelled monoprotic acid in an unknown amount of water titrated with a sample with a solution of NaOH of unknown molarity. After adding 10.0 mL of NaOH, the pH=5.0. The equivalence point is 32.22 mL of NaOH. What is the Ka? I have been looking ...
*March 8, 2011*

**calculus**

Determine the values of a and b for the function f (x) = ax^3 + bx^2 + 3x - 2 given that f (2) = 10 and f ′(-1) = 14. Please help, Thanks!
*March 1, 2011*

**SQL**

Explain why the following command would create an error, and what changes could be made to fix the error. SELECT V_CODE, SUM(P_QOH) FROM PRODUCT;
*March 1, 2011*

**chemistry**

you're right! sorry i guess im just tired from over studying that i saw the wrong letter!
*February 28, 2011*

**chemistry**

Degree of unsaturation why is it 5? C20H32CIN do i ignore the second C? because i did 21(2)+2=44 44-32+1-1 / 2 = 6 but i get it right with 20(2)+2=42 42-32-1+1 / 2 = 5 do i always ignore extra C's?
*February 28, 2011*

**french**

please unscramble this word.. the word is eeienhtocasr
*February 24, 2011*

**french**

thanks
*February 24, 2011*

**french**

can you unscamble eeienhtocasr
*February 24, 2011*

**math**

two thirds of 9 is 6 and one third of 18 is 6 if you draw a gragh of 9 divide it into three sections.each section is a third,two of those sections equal two thirds which is 6.now a graph of 18 divided into 3 sections each section is 6.each section represents one third. 6 is ...
*February 24, 2011*

**chemistry**

Write the major products with the correct regiochemistry and stereochemistry for 1- ethylcyclohexene and the following reagents: a) NBS, H2O, DMSO if someone could atleast direct me to a site or anything that would be great.
*February 22, 2011*

**Physics**

In the figure below, two blocks are connected over a pulley. The mass of block A is 12 kg, and the coefficient of kinetic friction between A and the incline is 0.22. Angle θ is 30°. Block A slides down the incline at constant speed. What is the mass of block B?
*February 21, 2011*

**calculus**

Consider the graph of y2 = x(4 − x)2 (see figure). Find the volumes of the solids that are generated when the loop of this graph is revolved about each of the following
*February 21, 2011*

**chemistry**

Mechanism for the reaction between 3-methyl-2-pentene and HCl. is this right? %img836.imageshack.us/i/questionk%.jpg/% * delete the percentages for the link to work, its the only way i could post a link
*February 19, 2011*

**chemistry**

Write down the correct mechanism for the reaction between 3-methyl-2-pentene and HCL?
*February 18, 2011*

**Econ**

Consider the following consumption function. C = 200 + .75(DPI), Where C is consumption, autonomous spending is 200, the MPC is .75, and DPI is disposable personal income. Using the Graph below, graph the Consumption Function. C 100 0 = Income On the Graph, label the point ...
*February 18, 2011*

**physics**

jkjkjkjkjkjkjkjkjkjkjk
*February 18, 2011*

**chemistry**

thanks, but didnt really find the answer to my question...
*February 17, 2011*