# Posts by Dan

Total # Posts: 1,181

**Math**

to identical jars are filled with equal amount of marbles. the marbles are coloured red or white. the ratio of red to white marblesis 7:1 in jar 1 and 9:1 in jar 2. if there are 90 white marbles altogether, determine the number of red marbles in jar 2.

*December 17, 2010*

**Physics**

f = ma u(k) * f(normal) = m*a u(k) *m*g=m*a u(k) *g =a a = 0.10 * 9.81m/s^2 = 0.981 m/s^2 this is defined to be a negative acceleration v = u + a*t so t = (v-u)/a and x = t * (v+u)/2 so together x = (v+u)(v-u)/2a where x = distance, v = final speed, u = initial speed, t = time...

*December 14, 2010*

**Chemistry**

How many grams of iron can be produced of 156000 calories of heat are absorbed by a large enough sample of iron III oxide

*December 12, 2010*

**Calc**

express 3ln(r)- 5ln(s)+ 7ln (t) as a single logarithm.

*December 9, 2010*

**chemistry - chromatography**

We used three different color dyes in both alcohol and water. So its the chemical makeup of each color that determines the Rf value?

*December 8, 2010*

**chemistry - chromatography**

Hello, can you tell me why different colors have different rf values

*December 8, 2010*

**Basic Electronics**

discuss your thoughts on the use of thevenin equivalent circuit.

*December 8, 2010*

**Physics**

The displacement from the equilibrium caused by a wave on a string is given by: y(x,t) = (-0.00200 m)sin[(40m^-1)x-(800s^-1)t]. What is the number of waves in 1 m?

*December 6, 2010*

**Physics**

Suppose a monatomic ideal gas is changed from state A to state D by one of the processes shown on the PV diagram. Find the total work done on the gas if it follows the constant temperature path A-C followed by the constant pressure path C-D. A = 2atm and 4L C = 1atm and 8L D...

*December 6, 2010*

**physics**

A town is planning on using the water flowing through a river at a rate of 5.0X10^6 kg/s to carry away the heat from a new power plant. Environmental studies indicate that the temperature of the river should only increase by 0.50ºC. The maximum design efficiency for this ...

*December 6, 2010*

**chemistry**

CuCl --> Cu+ & Cl- Ksp = [Cu+2] [Cl-] ========================= Cu+(aq) + 2 Cl ‾(aq) ==> CuCl2 ‾(aq) K = [CuCl2 ‾] / [Cu+2] [Cl-]^2 =============== (K) (Ksp) = [Cu+2] [Cl-] times [CuCl2 ‾] / [Cu+2] [Cl-]^2 reduces to: (K) (Ksp) = [CuCl2 ‾...

*December 4, 2010*

**chemistry**

Find out: a) How many grams of lithium are required? b) How many grams of each product can be produced?

*December 4, 2010*

**Math**

the rule is this: A prime can be written as a sum of two squares. I hope that helps

*December 4, 2010*

**com155**

ok I got it now.. thank you very much!!

*December 4, 2010*

**com155**

The role of education plays a big part in financial planning (PRESENT). It has worked a crucial part of becoming successful with your money (PRESENT PERFECT TENSE). It will help you in learning basic math skills in order to better your finances (FUTURE TENSE). The whole idea ...

*December 4, 2010*

**com155**

Okay! I hope this is it. The role of education plays a big part in financial planning (PRESENT). It has worked a crucial part of becoming successful with your money (PAST). It will help you in learning basic math skills in order to better your finances (FUTURE TENSE). The ...

*December 4, 2010*

**com155**

OK! I will try going over the site you sent me and try again.. Thanks a lot!

*December 4, 2010*

**com155**

HOW ABOUT THIS? The role of education plays a big part in financial planning (PRESENT). It has been a crucial part of becoming successful with your money (PAST PREFECT TENSE). It will help you in learning basic math skills in order to better your finances (FUTURE TENSE). The ...

*December 4, 2010*

**com155**

OH! Thank you! I did not know it said that. I am having trouble understanding it. thank you! So, does that mean I have to start all over? Did I at least get all the verbs right?

*December 4, 2010*

**com155**

Write five sentences about the role of education in successful financial planning, in which you correctly use a different verb tense in each sentence. Mark each verb used in bold and, in parentheses, identify the specific tense used The role of education plays a big part in ...

*December 4, 2010*

**English 101**

MARVELOUS 1. extraordinarily good; used especially as intensifiers 2. too improbable to admit of belief 3. being or having the character of a miracle UNCANNY of a strange nature; weird; mysterious Example That two people could be so alike was uncanny.

*December 4, 2010*

**com155**

thank you

*December 4, 2010*

**com155**

Yes! That is what I am trying to figure out.

*December 4, 2010*

**com155**

Write five sentences about the role of education in successful financial planning, in which you correctly use a different verb tense in each sentence. Mark each verb used in bold and, in parentheses, identify the specific tense used. THIS IS WHAT I WROTE: The role of education...

*December 4, 2010*

**physics**

thanks, I see where I messed up at...

*November 30, 2010*

**physics**

The Cedar Bluff express KAT bus averages 15 mph for 20 minutes, and then 32 mph for 14 minutes. What was its average speed? (mph)

*November 30, 2010*

**physics**

Suppose that you measured the moment of inertia of the system as I = 5.05 kg-m2. Assume the diameter of the pulley around which you wrap the string is d = 2.5 cm. a) suppose the system is initially spinning at angular speed ωo = 2.05 rad/s. After you drop a cube of mass ...

*November 30, 2010*

**Calculus**

i still did not understand. if u don't mind could you please explain it again and also the question asks for the intervals and the points. could you give the intervals and points for the the questions above in the questions .. Thanks a bunch :).

*November 29, 2010*

**Calculus**

Find: (a) the interval(s) on which f is increasing, (b) the interval(s) on which f is decreasing, (c) the open interval(s) on which f is concave up, (d) the open interval(s) on which f is concave down, and (e) the X-coordinate(s) of any/all inflection point(s). f(x)= (x^4) - (...

*November 29, 2010*

**calculus**

A cone of radius r centimeters and height h centimeters is lowered point first in at a rate of 1 cm/s into a tall cylinder of radius R centimeters that is partially filled with water. How fast is the water level rising at instant the cone is completely submerged?

*November 19, 2010*

**Math**

Solve: x'=x+y+2t y'=x+y-2t

*November 18, 2010*

**physics**

80cm=0.8m T=25/14=1.786...seconds v=(2pi*r)/T=2pi(0.8)/1.786...=2.815...m/s a=v^2/r=2.815...^2/0.8=9.904m/s^2, towards the centre along the radius vector of the circle

*November 16, 2010*

**math**

The first angle of a triangle is 24 more than the second. The third angle is twice the first. Find the measure of the angle of the triangle.

*November 15, 2010*

**Physics Spring**

A mass sitting on a horizontal, frictionless surface is attached to one end of a spring; the other end is fixed to a wall. 1.0 J of work is required to compress the spring by 0.12 m. If the mass is released from rest with the spring compressed, it experiences a maximum ...

*November 15, 2010*

**physics please help**

The femur is a bone in the leg whose minimum cross-sectional area is about 3.60 10-4 m2. A compressional force in excess of 6.90 104 N will fracture this bone. (a) Find the maximum stress that this bone can withstand. (b) What is the strain that exists under a maximum-stress ...

*November 14, 2010*

**Flec**

what is a prime factor? How do I find the prime factor?

*November 9, 2010*

**physics help**

i don't get this either please help me thanks.

*November 8, 2010*

**physics please help me**

i understand but how to i go about solving this that's what i need help in, if that assumption is made.

*November 7, 2010*

**physics please help me**

A 5.00 kg ball (ball 1), moving to the right at a velocity of +4.00 m/s on a frictionless table, collides head-on with a stationary 7.60 kg ball (ball 2). Find the final velocities of the balls if the collision is as specified below. (a) elastic collision ball 1 = -.825 ball 2...

*November 7, 2010*

**physics please help me**

The pole vault landing pad at an Olympic competition contains what is essentially a bag of air that compresses from its "resting" height of 1.1 m down to 0.1 m as the vaulter is slowed to a stop. (a) What is the time interval during which a vaulter who has just ...

*November 5, 2010*

**chemistry**

0.45

*November 4, 2010*

**Calculus**

P(x)= -x^3+15x^2-48x+450, x>/3 is an approximation to the total profit (in thousands of dollars) from the sale of x hundred thousand tires. find the number of hundred thousands of tires that must be sold to maximize profit.

*November 4, 2010*

**Calculus**

find the absolute extrema if they exist as well as where they occur f(x)= x-1/x^2+3x+5

*November 4, 2010*

**Calculus**

Find all extrema, inflection points, and asymptotes where applicable f(x)= 2x^3-12x^2+18x I got 0, 8 for extrema 2, 0 for I.P and I don't know how to find asymptotes

*November 4, 2010*

**Calculus**

Find the indicated absolute extremum as well as all values of x where it occurs on the specified domain f(x)= x^2e^-0.25x ; [3,10]

*November 4, 2010*

**Math please help!**

x=speed of boat in still water. assuming the problem implies 26 miles each way. to figure this out, I wrote this out in simple miles per hour terms. Example: (hours/mile)*miles + (hours/mile)*miles = hours so: (1/(x+5))*26+(1/(x-5))*26=10.6 x+5 represents the speed of the boat...

*November 3, 2010*

**chem need assistance**

Write a balanced chemical reaction to show the reaction between ammonium and a chlorite? Is this correct? 2NH3 + CLO2 + H2O ⇒ NH4Cl + NH2O2

*November 1, 2010*

**chem**

complete this reaction 2 NaNO3 + ht →

*November 1, 2010*

**chem**

Complete the reaction? IF no reaction say so H2O C4H6O3 ====> H2O c) Cu ===== > H2O d) K2O=====> e) 2 NaNO3 + ht →

*October 31, 2010*

**HELPPPPP**

so im done with everything except fro this question : A(n) 2.3 kg object moving with a speed of 8.6 m/s collides with a(n) 4 kg object moving with a velocity of 8.8 m/s in a direction39.0135◦ from the initial direction of motion mof the 2.3 kg object.What is the speed of...

*October 27, 2010*

**Chemistry**

Determine the mass of zinc sulphide,ZnS which is produced when 6.2 g of zinc and 4.5 g of sulphur are reacted. This question is really confusing me, and I'm not sure where to start. I think I have to calculate the moles of each given reactant first in which case I have: ...

*October 17, 2010*

**Chemistry**

Determine the mass of zinc sulphide,ZnS which is produced when 6.2 g of zinc and 4.5 g of sulphur are reacted.

*October 17, 2010*

**Chemistry**

I'm not understanding. what do you mean figure the moles of H2O2 in 3.4 g of water? You get the same number of moles of water? I calculated: nH2O2 = 3.4g/34.02g/mol= 0.0999412 mol Water on the other hand has 18.02 mol sorry but I'm not understanding. I think for this ...

*October 17, 2010*

**algebra**

two planes take off from an airport at the same time and head in opposite directions at 260 mph and 275 mph respectively. in how many hours will they be 1605 miles apart?

*October 16, 2010*

**chemistry**

Suppose you put 50mL of water in the can instead of 100mL and heated it to 40 degrees instead of 20 degrees. In what ways, if any, would this afect the results of the experiment? What would happen if you used 200mL of water and heated it only 10 degrees? Can you think of any ...

*October 6, 2010*

**College Physics**

A car starts from rest on a curve with a radius of 150 m and accelerates at 1.50 m/s^2. How many revolutions will the car have gone through when the magnitude of its total acceleration is 3.20 m/s^2 ?

*October 4, 2010*

**College Chem**

How many liters of carbon dioxide at 20 oC and 750 torr are produced when one gallon of toluene is burned? Convert liters to milliliters and then to grams. can you convert mil to grams?

*October 3, 2010*

**Chemistry**

1 gallon toluene = about 3,785 mL density = about 0.867 g/mL mass toluene = 3785 mL x 0.867 g/mL = 3282 grams. C7H8 + 9O2 ==> 7CO2 + 4H2O moles toluene = grams/molar mass = 3282/92 = about 36 moles. From the equation above, 1 mole C7H8 will produce 7 moles CO2; therefore, ...

*October 3, 2010*

**Chemistry**

can't convert ml to grams

*October 3, 2010*

**Chemistry**

How many liters of carbon dioxide at 20 oC and 750 torr are produced when one gallon of toluene is burned

*October 3, 2010*

**chemistry**

How much heat is released when one gram of toluene burned?

*October 3, 2010*

**Physics**

f = ma μk * f(normal) = m*a μk *m*g = m*a μk *g =a so a = μk*g this is defined to be a negative acceleration since the friction force works in the opposite direction to the movement of the puck vFinal = v0 + at so t = (vF-v0)/a d = t*(vF+v0)/2 so d = (vF+v0...

*September 29, 2010*

**German**

Actually, it is "Mein Name ist ... " or better and not as awkward (as being the correct German phrase) "Ich heiße ...".

*September 24, 2010*

**calculus**

Use the four-step process to find the slope of the tangent line to the graph of the given function at any point. (Simplify your answers completely.) f(x) = 2x^2 + 7x

*September 16, 2010*

**Astronomy and Space**

Using a telescope, which planets acn be observed from Earth in a crescent moon phase?

*September 14, 2010*

**chem2**

If you have an insulated glass of water at 25 oC containing 10 fluid oz at 25 oC, how much ice would you have to add to end up with a final temperature of 0 oC and no ice left?

*September 6, 2010*

**chem**

If this sample of dry ice were to be placed in an evacuated 1.0 L container and allowed to come to room temperature (25 oC), what would the pressure be?

*September 6, 2010*

**chem**

would you see a decrease in volume

*September 6, 2010*

**chem**

If ice were to be placed in a container at a temperature of -2 oC, with a water vapor pressure of 2 torr, you would see a decrease in the volume of solid ice over time.

*September 6, 2010*

**chem**

283.5 x .5 + 10 x 1 X (X)=0

*September 6, 2010*

**chem**

If you have an insulated glass of water at 25 oC containing 10 fluid oz at 25 oC, how much ice would you have to add to end up with a final temperature of 0 oC and no ice left?

*September 6, 2010*

**Physical Science**

.In the early 1900s, two associates of New Zealander Ernest Rutherford bombarded thin sheets of gold with positively charged subatomic particles. They found that most of the particles passed right through the sheets but some bounced back as if they had hit something solid. ...

*September 3, 2010*

**math**

You are offered two different sales jobs. The first company offers a straight commission of 4% of the sales. The second company offers a salary of $ 500 per week plus 2% of the sales. How much would you have to sell in a week in order for the straight commission to be equal to...

*August 30, 2010*

**Accounting**

HOW DO I find the net icome for this company with this information? Beginning of the year: ASSETS WERE $810,000 lIABILTES WERE:$324,000 eND OF YEAR: aSSETS WERE: $1,296,000 AND lIABILTES WERE:$540,000. cAPITAL STOCK OF $162,000 WAS ISSUSED dIVIDENDS OF $72,OOO WERE PAID

*August 29, 2010*

**accounting**

How do I find the net income for this company ,with this information? Beginning of year Total Assets were:$810,000 Total liabilites were:$324,000 End of year Total Assets were:$1,296,000 Total liabiltes were:$540,00 Capital stock of $162,000 was issued dividends of $72,000were...

*August 27, 2010*

**algebra 2**

I'm stuck on this one: factoring polynomials from algebraic expressions (and it says you can use the substitution method): 3m^2(2p^2+3)over (x^2+y)(2x-y^2) minus 6m(2p^2+3)over (y^2-x)(2x-y^2)= Do I find the GCF? I get 3m(m-2) over (x^2+y)(2x-y)(y^2-x) ????

*August 15, 2010*

**algebra 2**

I'm stuck on this one problem. The directions say: Solve the following leaving the sq. rt. in it's simplest form: sq.rt of 33+ sq.rt of 96 - sq.rt of 3 = I think it can't be simplifed---am I correct? (the directions did say that some of the problems can't be ...

*August 14, 2010*

**xacc 280**

Post one or two new concepts you learned from each of the PhxKlips

*July 31, 2010*

**Physics**

It took a stopping train 41/4min to travel between two stations 11.2km apart.The train accelerated uniformly during the first 11/4min of the journey,and decelerated uniformly to rest during the last 3/2min of the journey.The train had moved with uniform speed during the ...

*July 11, 2010*

**Mec 123**

A flywheel rotating at 5.3 revolutions per second has an angular retardation of 4/5 radian per second per minute.calculate:(i)its angular velocity after 45 seconds(ii),the number of revolutions it makes in 1 minute, and in coming to rest.

*July 10, 2010*

**math**

Show that x^2+y^2-6x+4y+2=0 and x^2+y^2+8x+2y-22=0 are orthogonal.

*July 9, 2010*

**German**

Yup. Some English here, please :) ... Would help a lot.

*June 22, 2010*

**college**

You're thinking of investing in a automation project to reduce cost of production. -Investment in Fixed Assets: $900,000 at t=0; salvage value of $300,000 at t=6; straight line deprectiation over 6 years (assume book value is 0 at t=6) -Investement in NWC: $250,000 at t=0...

*June 19, 2010*

**geometry**

A spherical water tank has a diameter of 10 feet. How much water does it hold when half full (use 3.14 for , and round to the nearest hundredth)?

*June 19, 2010*

**trig**

X=38.21

*June 7, 2010*

**Fracture Math word**

Dig

*May 11, 2010*

**Chemistry**

Is 20.0 mL of 3.0 M HF a buffer solution with an approximate pH of 3?

*May 4, 2010*

**Chemistry**

What is the molar solubility of silver sulfide, Ag2S? (Ksp for Ag2S is 6.0 x 10^51.)

*May 4, 2010*

**chemistry**

what volume would 8g of He at.951 atm and 25c occupy?

*May 2, 2010*

**algebra-is this right**

A basketball player has a vertical leap of about 36 in. If the equation d=48t^2 describes his hang time t as a function of his vertical leap d. what is his hang time? Show your work. 36=48t^2 t^2=3/4 t=(1/2)sqrt(3)seconds

*April 25, 2010*

**algebra**

Thank you for your help and reminding me there is two answers.

*April 25, 2010*

**algebra**

I was wondering if my answer is right. Let f (x)=(x+10)^2. Find x so that f(x)=72 (x+10)^2=72 x^2+20x+100=72 x^2+20x+28=0 x=(-20+-sqrt(400-112))/2 x=-10+6*sqrt(2)

*April 25, 2010*

**algrebra**

Solve by applying the quadratic Formula: all radicals should be simplified as far as possible. Show your work. a^2 -12a + 35 =0

*April 25, 2010*

**algebra**

Yes you helped me a lot. Thank you for showing me in steps how to solve this question

*April 25, 2010*

**algebra**

How do you complete the square by filling in the two blanks so as to produce a true equation. x^2 - 12x + ---- = (x - -----)^2

*April 25, 2010*

**Brain Teaser**

When Professor Sum was asked by Mr. Little how many students were in his classes, he answered, “All of them study either languages, physics, or not at all. One-half of them study languages only, one-fourth of them study French, one-seventh of them study physics only, and ...

*April 15, 2010*

**math**

Question from the Classroom: 10 A student claims that the equation Ö(-x) = 3 has no solution, since the square root of a negative number does not exist. Why is this argument wrong?

*April 13, 2010*

**math sets**

Explain whether the set {0, 1, 2} is closed with respect to addition on whole numbers.

*April 13, 2010*

**math 213 #18**

A student claims that every prime greater than 3 is a term in the arithmetic sequence whose nth term is 6n + 1 or in the arithmetic sequence whose nth term is 6n – 1. Is this true? If so why?

*April 13, 2010*

**Math 213**

Examine several newspapers and magazines and describe at least three examples of functions that appear. What is the domain and range of each function?

*April 13, 2010*