# Posts by carl

Total # Posts: 298

**Calculus (math)**

A rescue cable attached to a helicopter weighs 2 lb/ft. A 190 lb man grabs the end of the rope and is pulled from the ocean into the helicopter. How much work is done by lifting the man if the helicopter is 50 ft above to water.

**Statistics**

how can I decide to reject or fail to reject the following null hypothesis? let a= 0.05,data; p=0.69, n=32, test statistic z= 0.09095 H(0);p=0.68 H(1)p>0.68

**Statistics**

how can I determine weather to reject or fail to reject the following nul hypothosis: let a= o.01, data: s= 3.1, n=55 and H(0) st dev 2.8 and H(1)< 2.8

**chem**

ln[80/100]=-k[84.2] -2.2=-k[84.2] -2.2/-84.2=k k=0.0261min^-1

**Calc**

Find the present value of $14000 due in 9 years at the given rate of interest. (a) 2%/year compounded semiannually? (b) 5%/year compounded semiannually?

**chemistry**

Calculate the increase of entropy in J/K when 8.6 mole of C 2 H 5 OH melts at (-114) o C and 1 atm. ΔH fus = 5.02 kJ/mol

**College Statistics**

probilbility summary low birth weight and smoking moms how to calculate prevanece eatios

**Organic Chemistry**

please homework help A bowl of 582 g of water is placed in a microwave oven that puts out 729 watts (J/s). How long would it take in seconds to increase the temperature of the water from 12.0oC to 46.6oC?

**Gen. Chem**

Could you help me with this homework please.. 105.0 g of water is in a Styrofoam calorimeter of negligible heat capacity. The initial T of the water is 17.1oC. After 288.2 g of an unknown compound at 77.0oC is added, the equilibrium T is 25.1oC. What is the specific heat of ...

**math**

my name is carl

**Math**

Make a tree diagram of all the possible arrangements of the word veer

**njit**

i did it but i can't find the right answer i tried several times but i cant get the result please help me out

**njit**

please life saver i am taking a quiz now can some one help me with this pleeeeeeeaaaaaaaaassssssseeee Calculate the pH of 0.175 M phosphoric acid (H3PO4, a triprotic acid). Ka1 = 7.5 x 10-3, Ka2 = 6.2 x 10-8, and Ka3 = 4.8 x 10-13.

**chem 126**

i did it i found 0.4 but wrong

**chem 126**

Phenolphthalein is a commonly used indicator that is colorless in the acidic form (pH < 8.3) and pink in the basic form (pH > 10.0). It is a weak acid with a pKa of 8.7. What is the ratio of the conjugate base concentration to the acid concentration, that is, [B-]/[HB] ...

**Improving Vocabulary Skills**

Chapter 13 the Sentence Check 2 A curtail,B devastate,C Digress,D incentive, E Incorporate,F Indispensable, G Intermittent, H Rigor, I Squander,J succumb. co

**TRIGONOMETRY HELP**

Thank You!!!

**TRIGONOMETRY HELP**

Prove that: cos²Θ - sin²Θ = 2cos²Θ - 1

**sciences**

A solution contains 0.0180 M HNO3, 0.0268 M HI, and 0.250 M formic acid, HCOOH. What is the pH?

**TRIGONOMETRY HELP**

Thank You!!!

**TRIGONOMETRY HELP**

Prove that: (tan²Θ)x(sin²Θ) = (tan²Θ)-(sin²Θ) show work

**Art History**

What may have been one cause for the relative lack of artistic production in Florence during the High Renaissance (after the death of Lorenzo), and the relative increased artistic production in Rome during this period?

**Urgent Chem Help**

A certain substance has a heat of vaporization of 55.30 kJ/mol. At what Kelvin temperature will the vapor pressure be 3.50 times higher than it was at 361 K?

**Science**

Some nitrogen atoms have seven neutrons and some have eight neutrons. These two forms of nitrogen are: a. ions of each other b. phases of each other c. isotopes of each other and how exactly do you know? My book doesn't cover this at all yet its in my homework so im not sure

**Scientific Notation**

I got all of them so far EXCEPT this one... help? Thank you! Convert the following into scientific notation: 1/137

**Math**

Compute the following special functions. Keep the correct number of significant figures. 10^5.4 Can somewhere help me with this? Is it as simple as putting it into my calculator just like that? if so, how do I know what the correct number of sig figs are since the worksheet ...

**trig/sig figs**

There are 60" in 1', 60' in 1°, and 2π radians in 360°. Convert arc-seconds into radians. KEep 6 significant figures. If someone could help and walk me through this process, it would be soooo appreciated!

**multiplying and significant figs**

Thank you so much! What about 1300 * 2.16? I know that probably also looks very simple but sig figs are confusing me, such a new concept.

**multiplying and significant figs**

Multipy and keep only the correct number of significant figures. 101.6 * 3

**astronomy/conversion**

There are 365.25 days in a year, 24 hours in a day, 60 minutes in an hour, and 60 seconds in a minute. Convert years into seconds. Show your work and keep 5 significant figures. Ok, so finding it is easy (multiply 24, 60, 60 and 365.25) but how does the significant figures ...

**Significant Figures**

I'm having a hard time with significant figures. Any help would be appreciated. The first one is 0.0000000502. I put that it has three significant figures. Is this correct? The other numbers I haven't a clue about are: 5.52 299,792,458 206,265 I get the jist of it, but...

**Pre Calc**

1. Describe the linear programming situation for this system of inequalities. x<(or equal too)1 y>(or equal too)0 3x + y<(or equal too)5 2. Describe the linear programming situation for this system of inequalities where you are asked to find the maximum value of f(x, ...

**college bookkeeping**

You would be correct in assuming A or C if the question is reffering to the transaction analysis. The question reffers to "for a period". This would mean that the question is reffering to transfering the net income to the financial statements. The only financial ...

**algebra**

90 tiles

**physics**

It takes you 7.3 min to walk with an average velocity of 1.5 m/s to the north from the bus stop to the museum entrance. How far did you walk? Answer in units of m

**physics**

a couple part in a car on moonlit evening. Find that their car is stop in the sand. The women having studied physics, ties a rope to the car's bumper and stretches it around a tree in front of a car. She then pushes with 200 newton force against the horizontal. The cars ...

**physics**

water leaves a hose at a rate of 1.5kg/s with a speed of 20m/s and is aimed at the side of a car, which stops it (splashing back is ignored). what is the force exerted by the water on the car?

**physics**

suppose the glider is initially at rest at x=0, with the spring unstretched. You then apply a constant force in the +x direction with magnitude 0.610 N to the glider. what is the glider's velocity when it has moved 0.100m?

**physics**

suppose the glider is initially at rest at x=0, with the spring unstretched. You then apply a constant force in the +x direction with magnitude 0.610 N to the glider. what is the glider's velocity when it has moved 0.100m?

**stat**

for randomly selected adults, IQ scores are normally distributed with a standard deviation of 15. the scores of 14 randomly selected college students are listed below. use a 0.10 significance level to test the claim that the standard deviation of IQ scores of college students ...

**statistic**

suppose we wish to construct a confidence interval for a population proportion p. if we sample without replacement from a relatively small population of size N, the margin or error E is modified to include the finite population correction factor as follows: E=Za/2 pq/n N-n/N-1...

**trig**

Prove: sin(x–y)sin(x+y)=sin^2(x)–sin^2(y)

**Chemistry**

Given the following equation: Na2O + H2O ---> 2 NaOH. How many grams of NaOH is produced from 1.20 x 10^2 grams of Na2O? How many grams of NaO2 are required to produce 1.60 x 10^2 grams of NaOH?

**chemistry**

A plastic container with a mass of 30 grams gains 1,140 joules of heat. If the temperature of the container increases 20°C, what is the specific heat of the plastic in the container?

**smu**

In a bumper test, three types of autos were deliberately crashed into a barrier at 5 mph, and the resulting damage (in dollars) was estimated. Five test vehicles of each type were crashed, with the results shown below. Research question: Are the mean crash damages the same for...

**SMU**

A sample of 25 concession stand purchases at the October 22 matinee of Bride of Chucky showed a mean purchase of $5.29 with a standard deviation of $3.02. For the October 26 evening showing of the same movie, for a sample of 25 purchases the mean was $5.12 with a standard ...

**Trig**

In ABC, vertex C is a right angle. Which trigonometric ratio has the same trigonometric value as Sin A? A Sin B B Cosine A C Cosine B D Tan A

**Trig**

Which trigonometric function can equal or be greater than 1.000? A Sine B Cosine C Tangent D none of the above

**Physics**

10m/s

**Chemistry (PLEASE HELP ME)**

the answer in number 1 is b

**calculus**

What is the length of the blue line labeled r in the image below? Give your answer in terms of a and b. blue line labeled r starting at the origin and ending at a point a,b b|------------| | /| | / | | / | | / | | / | | r / | | / | | / | | / | | / | | / | _|____________|a

**biology**

1/10,000,000 moles/liter

**MATH**

how do you wite an equation for the function in a problem like 4x+y=-10?

**math algerbra 1**

how do you solve for the function in a problem like 4x+y=-10?

**math**

solve the equation by factoring. 3x(x-5)=6x^2-16x

**algebra**

Does the function y = 2^x ever cross the x-axis? Explain why or why not

**algebra**

any help would be greatly appreciated :)

**algebra**

A boat can travel 114 miles upstream in the same time that it can travel 186 miles downstream. If the speed of the current is 6 miles per hour, find the speed of the boat without a current.

**statistics**

3. A researcher is interested in comparing the Christian maturity level of students who volunteer for community service versus those who do not. The researcher assumes that those who perform community service will have higher Christian maturity scores. The maturity scores tend...

**statistics**

2. A teacher wants to investigate whether there is a difference between male and female students in the amount of time they spend studying for statistics. The table below shows the amount of time students spend studying statistics each week. The amounts of time spent studying ...

**statistics**

3. A researcher is interested in whether listening to music helps or hinders test-performance. To control for differences in cognitive level, this researcher decides to use a within-participants design. He selects a random sample of participants and has them study different ...

**statistics**

2. A teacher wants to investigate whether there is a difference between male and female students in the amount of time they spend studying for statistics. The table below shows the amount of time students spend studying statistics each week. The amounts of time spent studying ...

**statistics**

1. An LU professor is interested in whether there is a difference between undergraduate students and graduate students in the amount of time spent praying each day. The professor gathers information from random samples of undergraduate and graduate students on the LU campus. ...

**statistics**

1. A researcher is interested in whether students who attend private high schools have higher average SAT Scores than students in the general population. A random sample of 90 students at a private high school is tested and and a mean SAT score of 1030 is obtained. The average...

**statistics**

6. In a study on caffeine and stress, college students indicated how many cups of coffee they drink per day and their current stress level on a scale of 1 to 10. The table shows the survey results. Using a web-calculator, obtain the appropriate correlation coefficients. Number...

**MATH**

How would you go about finding x and y?? [x-8 2 2y] [9x-16 2 6] [ 2 -7x 7] = [ 2 -7 7] [-4 y-4 2] [-4 -1 2]

**trig**

How would you go about finding x and y?? [x-8 2 2y] [9x-16 2 6] [ 2 -7x 7] = [ 2 -7 7] [-4 y-4 2] [-4 -1 2]

**Chemistry**

1How would each of the following affect the accuracy of the calculated neutralizing power of antaid (too high, too low, no effect) explain a)The actacid tablet was not cut exactly in half before weighing b)The solution mixture of reacted antacid and excess HCL spattered out of...

**I need help to unscramble these words in spanish**

oaincooEdm arAilulq incEle asertdarccteoipPr erIoscrdapm loEcernoict lpaLaeliuc mroipliEeltbe

**Math 11th Grade**

Use Demoivre's Theorem to find the fourth roots of -16. Leave the four roots in trigonometric form. How the heck do i do this?

**Math**

since they have the same y value, the line is vertical. So there is no y in the equation. The equation could be A= (any# except 0)x and that's it.

**Math**

how do i write that in terms of An? like An= (2)^n(-1)^n some thing like that? or is that right

**Math**

What is the equation for the sequence 1, 2, 1/4, 8, 1/16, 32,......

**math**

b = 20 + 1/2(t-1975) kg/person I think that's right/my guess, no promises =]

**Chemistry**

-5280 J

**Precalc**

What name is given to figures (wave) to indicate that points are attracted to only certain regions in the plane and no to others?

**Chemistry**

You are titrating 35.00 mL of a 1.20 M solution of HCOOH with a strong base. If you add 1.00 mL of a 3.60 M solution of sodium hydroxide, what is the final pH of the acid solution? The Ka for HCOOH is 1.8 X 10-4.

**Chemistry**

Thank You so much! I really appreciate the help!

**Chemistry**

What is the pH of a 0.94 M solution of HBrO that is also 0.59 M in magnesium hypobromite, the salt of it's conjugate base? The Ka for HBrO = 2.8 X 10-9.

**Physics**

image5.65.jpg

**Physics**

When a patient’s injured neck is healing, it is often desirable to prevent the weight of the head from pushing down on the neck. This can be accomplished with the system of pulleys shown in the figure. The pulleys are all small and extremely light in weight and have no ...

**math**

Venus begins a new year every 225 days. Earth begins a new year every 365 days. If both planets begin a new year on the same day, how many days will pass befor that happens again.

**math**

Venus begins a new year every 225 days. Earth begins a new year every 365 days. If both planets begin a new year on the same day, how many days will pass befor that happens again.

**math**

3-2x+4=21

**ENGLISH**

Testcles

**Math (URGENT)**

write a formula that gives you the number of regions formed when x points are placed on a circle and all possible chords are drawn. ex. 2pts has 2 regions, 3pts has 4 regions, 5pts has 17 regions

**Math**

write a formula that gives you the number of regions formed when x points are placed on a circle and all possible chords are drawn. ex. 2pts has 2 regions, 3pts has 4 regions, 5pts has 17 regions

**geometry**

The sum of the measures of the interior angles in a polygon is 540 degrees. How many sides does the polygon have?

**math**

One of your friends is heading north for the Christmas holiday and the other friend is heading south. If their destinies are 1029 miles apart and one car is traveling at 45 miles per hour and the other car is traveling at 53 miles per hour. How many hours before the two cars ...

**world lit**

Which word did not originate from those used in various occupation? 1.seasons 2.person 3.tease 4.broker

**vocabulary skills**

which greek base means eye? 1.neur 2.myel 3.phren 4.ophthalm

**vocabulary skills**

the greek combining form -pathy means: 1.abnormal discharge. 2.tumor arising in or composed of. 3.disease of. 4.treatment of.

**lit**

which word is not derived from terms used in drama? 1.chorus 2.pants 3.scene 4.size

**Physics**

1.) A lawnmower engine claims to provide 18 hp of power and 6.25 ft lb of torque. If this is true, what must be the rotational speed in RPM? 2.) The conversion of the shaft power of a wind turbine to electricity is the function of the generator. Assume it has an efficiency of ...

**Physics**

A cylinder with a valve at the bottom is filled with an ideal gas. The valve is now opened and some of the gas escapes slowly. The valve is then closed, after which the piston is observed to be at a lower position. Assume that the system is in thermal equilibrium with the ...

**greek vocab.**

which word did not originate from the word of the arts? 1. maudlin 2. martyr 3. character 4. colossal

**lit**

which word did not originate from military language? 1 pioneer 2 phrase 3 salary 4 trophy

**Chemistry**

yes Im sorry, it was for M

**Chemistry**

How do I set up my equation to determine what the pH will be when the concentration of Fe^3+ is reduced to 10^-7? The previous part of the question had me find what the pH would be for the Fe(OH)3 to precipitate at 0.20 M. which i found was 1.37

**Calculus**

A particle is moving along the curve y = 2 √{3 x + 7}. As the particle passes through the point (3, 8), its x-coordinate increases at a rate of 4 units per second. Find the rate of change of the distance from the particle to the origin at this instant.