Wednesday

October 22, 2014

October 22, 2014

Total # Posts: 6,303

**Chem...**

1) what is the density of methane (CH4) at a temp. of 20C and a pressure of 684mm. 2) a gas has a density of 2.5g/L at a temp. of 20C and a pressure of 1.1 atm. what is its molar mass.
*April 12, 2012*

**Math**

As a fraction it is 60/100 but you probably need to simplify it so find a common factor of both, in this case the number 20, and divide both 60 and 100 by that to get the fraction of 3/5. 60% is equal to .6 because 100% equals 1.
*April 12, 2012*

**Physics**

The formula to use is c=f*lambda where c equals speed of a wave, f is frequency, and lambda is the Greek for wavelength. So to find the speed you multiply 9 by .654 and the answer should be 5.886 m/s.
*April 12, 2012*

**math**

I believe to find the sum of the exterior angles of a n-sided polygon is (n-2)*180 where n is the number of sides. So for a 50-sided polygon it should be 8640 degrees. For the interior angles it is (n-2)*180/n where again n is the number of sides.
*April 12, 2012*

**Math**

For a line to be perpendicular to another line you need to use m in the linear equation of y=mx+b and find the opposite and reciprocal of that number. In this case m is 3 so the opposite of 3 is -3 and the reciprocal is just flipping the fraction of -3/1 so it is now 1/-3. Now...
*April 12, 2012*

**Physics**

Where must an object be placed to have a magniﬁcation of 3.74 in front of a converging lens of focal length 14.1 cm? Answer in units of cm
*April 12, 2012*

**Science**

D because mechanical energy is basically kinetic energy and when that is greater than the force of gravity then it will not fall down.
*April 12, 2012*

**Physics**

Three identical small Styrofoam balls of mass 1.53 g are suspended from a ﬁxed point by three nonconducting threads, each with a length of 56.4 cm and negligible mass. At equilibrium the three balls form an equilateral triangle with sides of 31 cm. What is the common ...
*April 12, 2012*

**algebra**

For the area of a circle is πr² as you stated so all you do is set 400 equal to πr² and solve for r. 400=πr²/π 127.32=r² √127.32)= r r=11.3 Same thing for this except you use 800 instead of 400 so. 800=πr² 254.64=r²...
*April 12, 2012*

**math**

You have 7 red marbles and 5 green marbles in a bag. You select one, do not replace it then select another. Find P(red,red) and P (green,green). Write probabilites as a percent and rounded to the nearest whole percent. Find P(red,green) and P (green,red). Compare.
*April 12, 2012*

**Physics**

Three identical small Styrofoam balls of mass 1.53 g are suspended from a ﬁxed point by three nonconducting threads, each with a length of 56.4 cm and negligible mass. At equilibrium the three balls form an equilateral triangle with sides of 31 cm. What is the common ...
*April 11, 2012*

**Chemistry**

What 3 compunds can be used to prepare oxygen in the laboratory? What are the reactions for each of the three compounds?
*April 10, 2012*

**College Algebra**

Annual profit in thousands of dollars is given by the function, P(x) = -.1x^2 + 50x - 300, where x is the number of items sold , x >= 0. 1.describe the meaning of the number -.1 in the formula. 2.describe the meaning of the number -300 in the formula. 3.find the profit for ...
*April 9, 2012*

**physics**

A down jacket has a surface area of 0.82 m2 and is filled with a 3.8 cm thick layer of down, which has a thermal conductivity of 6.0 10-6 kcal/(s · m · C°). The coat is worn by a person whose skin temperature is maintained at 27° C. The outer surface of ...
*April 9, 2012*

**physics**

The sun is 1.5 1011 m from the earth. (a) Over what surface area is solar radiation spread at this distance? (b) What is the total power radiated by the sun? (The sun delivers energy to the surface of the earth at a rate of approximately 1400 W/m2.) (c) Treating the sun as a ...
*April 9, 2012*

**physics**

A pot containing 1.09 liter of water, initially at 18°C, is placed on a 1101 W electric heating element. (a) How much heat must be supplied to the water to bring it to a boil? (b) How much heat is necessary to boil all the water away? What is the minimum time required to ...
*April 9, 2012*

**Financial Math**

Suppose that you decide to lease a car. At the end of the 48-month lease period, you need to make a lump-sum payment of $5000 if you want to keep the car. You decide to save up, just in case you decide to keep the car; if you don’t keep this car, you will still have saved...
*April 9, 2012*

**physics**

A 55.0 g ice cube, initially at 0°C, is dropped into a Styrofoam cup containing 318 g of water, initially at 18.2°C. What is the final temperature of the water, if no heat is transferred to the Styrofoam or the surroundings?
*April 9, 2012*

**physics**

How much energy expressed in units of food Calories (that is, kilocalories) is required to operate a 100 W light bulb for 14.70 hours?
*April 9, 2012*

**physics**

(a) How much heat is required to raise by 12.40°C the temperature of 1.4 kg of water. (b) How much heat is required to raise by 12.40°C the temperature of 1.4 kg of iron.
*April 9, 2012*

**math**

marcie, kim and yvonne are on the same softball team. (A). During the last season . Marcie hit 3 less than twice the number of home runs that kim hit let h represent the number of home runs that kim hit . write an expression that represents the number of home runs that Marcie ...
*April 8, 2012*

**english**

1. apa 2. mla 3. apa 4. mla 5. mla 6. apa 7. apa 8. mla 9. both 10. apa are these right answers
*April 8, 2012*

**english**

Choose and Place MLA, APA, or Both in the blank. _____1. In a work with a single author, the author’s last name and initials are listed in the works cited entries. _____2. In a work with a single author, the author’s full last name and first name are listed in the ...
*April 8, 2012*

**chemistry**

@Amanda, k
*April 7, 2012*

**Statistics**

Should companies use the same confidence interval each time a confidence interval is determined or should the level change based on situations? If it changes based on situations, what type of situations might call for higher confidence levels?
*April 6, 2012*

**Chemistry :((((**

Thank you so much!!! :)))))
*April 6, 2012*

**Chemistry :((((**

explain why the bond angles found for the molecules below is as given below. Methane 109.5 Ammonia 107.5 water 104.5
*April 6, 2012*

**english**

hello?
*April 5, 2012*

**english**

alright but what structure would it be?
*April 5, 2012*

**english**

i don't know
*April 5, 2012*

**english**

i just need help on it
*April 5, 2012*

**english**

well i know its not a infinitive phase
*April 5, 2012*

**english**

its asking what grammatical structure is italicized in the sentence
*April 5, 2012*

**english**

What grammatical structure is the italicized portion of the sentence? Although her personality had not changed at all, Megan looked quite different is it: adverb clause infinitive phrase past participial phrase elliptical clause adjective clause
*April 5, 2012*

**Chemistry**

During the synthesis of Ferrocene, deprotonation of cyclopentadiene is carried out using 1,2-dimethoxyethane (DME). If the deprotonation is carried out using MeOH, will the reaction be faster or slower? Why?
*April 5, 2012*

**Physics grade 12**

A horizontal beam of alpha particles are injected with a speed of 1.3x10^5 m/s into a region with a vertical magnetic field of magnitude 0.155T. A- How long does it take for an alpha particle to move half way through a complete circle? B- If the speed of the alpha particle is ...
*April 5, 2012*

**Economics**

How might expectations of a fiscal policy being temporary weaken the effects of the policy?
*April 4, 2012*

**Economics**

How could “politics” complicate fiscal policy?
*April 4, 2012*

**Economics**

Can you please explain the problem of time lags in enacting and applying fiscal policy?
*April 4, 2012*

**computer science**

Prove that the following language is not context free: L = {a^3^n : n >= 0}
*April 4, 2012*

**Essessentials of Communication(Speech)**

I've been stuck on this question for the longest and can't find help anywhere. Instructions Read the following statement; then respond with a question, content paraphrase, feeling paraphrase, and a combination of content and feeling paraphrase. Statement from Speaker...
*April 4, 2012*

**Government**

In which type of colony did strict governors anger the colonists? A. the royal colonies B. the proprietary colonies C. the charter colonies D. the informed colonies
*April 3, 2012*

**discrete mathematics**

prove the euclid division given and int j and k>0 then one can find a unique pair (q,r) of int state j=q*k +r and 0<r<k
*April 3, 2012*

**MATH**

tree diagra probability: tree diagram with three equal parts, what is the probability, if we spin twice of getting at least one a
*April 1, 2012*

**math**

In an experiment, Marissa must select a letter card below and spin the spinner once. A B C D 1 2 3 What is the probability that Marissa's outcome will be the letter card A and the number 3 on the spinner?
*April 1, 2012*

**Mechanics (A level), Please help**

A light string of length a is attached to two points A and B on the same level and distance b apart, where b < a. A smooth ring of weight W is threaded on the string and is pulled by a horizontal force P, so that it rests in equilbrium vertically below B. Show that tension ...
*April 1, 2012*

**Pre-Calc Helppp!!!**

Use the Law of Sines to solve for all possible triangles that satisfy the given conditions. (If an answer does not exist, enter DNE. Round your answers to one decimal place. Below, enter your answers so that B1 is smaller than B2.) a = 39, c = 40, angle A = 36° angle B1...
*March 31, 2012*

**Math**

Find the Dimensions of a rectangular garden of the greatest area that can be enclosed in 40 feet of fencing.
*March 31, 2012*

**Chemistry**

Consider the cracking of gaseous ammonia at constant total pressure of 1 atm and constant temperature. Find the equilibrium gas composition at 400 degree C. Given: The Gibbs free energy for the cracking reaction 2NH3 = N2 + 3H2, DeltaGo ( delta G standard) =87,030-25.8TlnT &#...
*March 29, 2012*

**Chemistry**

Calculate the partial pressure of monatomic hydrogen in hydrogen gas at 2000 K and 1 atm pressure. Given: (i) For ½ H2 -> H, DeltaHo298=217,990 J; DeltaSo298=49.35 J/K. (ii) Assume that the heat capacity of monatomic gas to be 3/2R (iii)The heat capacity of H2 assume...
*March 29, 2012*

**Economics**

How does government intervene to move an economy out of a recession?
*March 28, 2012*

**Economics**

What does the term “recession” mean and how do we know when one occurs?
*March 28, 2012*

**Economics**

What is “Gross Domestic Product” (G.D.P.)
*March 28, 2012*

**Economics**

How might earning a college degree increase lifetime earnings and employability?
*March 28, 2012*

**Economics**

Why might an increase of the minimum wage in the United States impact unemployment rates?
*March 28, 2012*

**physics**

A sharp image is located 83.0 mm behind a 62.0 mm focal-length converging lens. Find the object distance by calculation.
*March 28, 2012*

**probability**

tommy has 7 yellows 6 green 3 blues 8 red wht it tommy probability that she will not draw a green ball
*March 27, 2012*

**Astro**

Suppose you lived on a planet with the same radius as the Earth, but it had a density 2.99 times Earth's density. Your weight would be different on this planet. Find how much you would weigh on this planet divided by your weight on Earth
*March 27, 2012*

**Physics help please!!!**

so is part a .162m
*March 27, 2012*

**Physics help please!!!**

A 2.10 kg frictionless block is attached to an ideal spring with force constant 315N/m . Initially the block has velocity -3.75m/s and displacement 0.270m . Find (a) the amplitude of the motion. (b) the maximum acceleration of the block. (c) the maximum force the spring exerts...
*March 27, 2012*

**Chemistry**

1. What is the pH of a solution whose [H3O+] is 1 X 10 -5 M? 2. What is the [H3O+] concentration of a solution with a pH of 9? 3. What is the pH of a solution whose [H3O+] concentration is 3 X 10-3 M? 4. What is the pH of a solution with a [H3O+] concentration of 1 X 10 -12 M...
*March 27, 2012*

**math**

translate to an inequality. the average speed s, was between 80 and 100 mph. translation 80 s 100
*March 27, 2012*

**Algerba 2**

how to graph 1/3 <= x <= 1/2 "<=" meaning less than or equal to.
*March 26, 2012*

**Chemistry Help!!!!**

for each of the following pairs of elements, give the correct molecular formula, explain how you arrived at this answer( you may use the Bohr model notation, or the orbital model notation, or explain linguistically) and note whether the bonding is covalent or ionic. ( I tried ...
*March 26, 2012*

**math**

15,000 down payment, 20-year mortgage loan with annual 6% interest compounded monthly. The payment is $809. Trying to figure the final selling price. I can do all the steps except for calculating P.
*March 26, 2012*

**Chemistry**

2NO(g) + H2(g) --> N2O(g) + H2O(g) + energy. 1. Assume the reaction is reversible and at equilibrium. What shifts in the equilibrium of this reaction are suggested by Le Chateliers Principle?
*March 26, 2012*

**PHYSICS**

Calculate the force required to remove a suction cup of area 2.60 cm2 from the surface to which it is stuck.
*March 26, 2012*

**physics**

A man doing a slow push-up is approximately in static equilibrium. His body is horizontal, with his weight of 755 N supported by his hands and feet, which are 1.34 m apart. One hand rests on a spring scale, which reads 270 N. If each hand bears an equal weight, how far from ...
*March 26, 2012*

**physics**

A 85.0 N weight is held in the hand. The upper arm makes an angle of 29.0° with the vertical, and the lower arm is 13.0° above the horizontal. Find the tension in the biceps tendon.
*March 26, 2012*

**p**

A newly planted tree is supported against the wind by a rope tied to a stake in the ground, as shown in the figure below. The force of the wind, though distributed over the tree, is equivalent to a single force F, as shown in the figure. Find the tension in the rope. Assume ...
*March 26, 2012*

**physics**

An artist designs a mobile of light horizontal rods connected by vertical strings and supporting various shaped weights (see figure below). Find the magnitudes w2, w3, and w4 if w1 = 4.92 units of weight. The numerical values given in the figure all have units of length.
*March 26, 2012*

**Chemistry **

85.65 grams of barium hydroxide were dissolved in 2000ml of water. 88 grams of carbon dioxide were passed through the solution producing a white precipitate. what was this white precipitate and how many grams of it were produced.
*March 26, 2012*

**science**

A merry-go-round starts from rest and accelerates uniformly over 26.0 s to a final angular velocity of 5.50 rev/min.
*March 26, 2012*

**personal finance**

14000-12000=2000
*March 25, 2012*

**M1, Physics**

Two hooks A and B are fixed to a ceiling, where AB is 2.5 m. A small object of mass 3 kg is suspended from A and B by two light inextensible strings so that it is 2 m from A and 1.3 m from B. calculate the tension in strings
*March 24, 2012*

**Pre-Calc**

A hot-air balloon is floating above a straight road. To estimate their height above the ground, the balloonists simultaneously measure the angle of depression to two consecutive mileposts on the road on the same side of the balloon. The angles of depression are found to be 24&...
*March 23, 2012*

**Pre-Calc**

Evaluate the expression without using a calculator(show work please)? (sin pi/4 cos pi/6 - sin pi/6 cos pi/4) the answer is 1/4(2-ã3)
*March 23, 2012*

**math percentiges**

If the shoes cost 80.00 and i can get 30% off how would i set that problem up?
*March 23, 2012*

**Math**

A hemisphere of radius 7 sits on a horizontal plane. A cylinder stands with its axis vertical, the center of its base at the center of the sphere, and its top circular rim touching the hemisphere. Find the radius and height of the cylinder of maximum volume. radius: height:
*March 22, 2012*

**Math**

A box has a bottom with one edge 2 times as long as the other. If the box has no top and the volume is fixed at , what dimensions minimize the surface area?
*March 22, 2012*

**algebra**

What is the sum of the first 19 terms of the series: 63 + 55 + 47 + 39 + 31 + …? I think it is 769.5 is it right?
*March 22, 2012*

**algebra**

Sara bought some 6-penny nails and some 10-penny nails at ace hardware. She bought 2 more 6-penny nails than she did 10-penny nails. She had a total of 8 nails. How many 6-penny and 10 penny nails did sara purchase?
*March 22, 2012*

**physics**

A simple Atwood's machine uses two masses, m1 and m2. Starting from rest, the speed of the two masses is 7.0 m/s at the end of 5.0 s. At that instant, the kinetic energy of the system is 100 J and each mass has moved a distance of 17.5 m. Determine the values of m1 and m2.
*March 21, 2012*

**physics**

Period: 2pi/15, or one oscillation every 15 minutes. Freq: 1/15 Equation: let d be the displacement then d = 6cos(2pi/15t)
*March 21, 2012*

**Math**

alberto has 12 quarters, 10 dimes, 10 nickels, and 20 pennies. How many different combinations of coins can he make to have $2?
*March 20, 2012*

**MATH**

WHAT IS THE BASE AREA THE BOX? L=8 IN. W=3 1/2IN AND H= 13IN.
*March 20, 2012*

**physics**

A marble cylinder that has a diameter of 42 cm and stands 1.25 m tall rests on a flat tile deck. What is the pressure exerted on the deck by the cylinder?
*March 18, 2012*

**Physics Please help!**

In each of the following cases, the mass is 7.99 kg and the radius is 7.50 cm. (a) What is the moment of inertia (kg/m2 ) of a solid cylinder rotating about an axis parallel to the symmetry axis but passing through the edge of the cylinder? (b) What is the moment of inertia (...
*March 18, 2012*

**Math(Please help)**

.0397=-39.5x x should = -.00101
*March 18, 2012*

**Math(Please help)**

is it .0015 or .015 you wrote .0015 first then .015 second. if its .0015 then its .0397 not .0262
*March 18, 2012*

**Math(Please help)**

yes
*March 18, 2012*

**Math(Please help)**

x/.025 is (1/.025)*x 1/.025=40
*March 18, 2012*

**Math(Please help)**

first put the .015 on the other side by taking it away from the other side so .0262=-40x+.5x now add the x's .0262=39.5x solve for x
*March 18, 2012*

**math**

go through each of the possibilities of getting to 11. 1+10 2+9 3+8 4+7 and so on. think of what you are looking for, twice the girls age will be four more than the boys age.
*March 17, 2012*

**Physics Please help!**

In each of the following cases, the mass is 7.99 kg and the radius is 7.50 cm. (a) What is the moment of inertia (kg/m2 ) of a solid cylinder rotating about an axis parallel to the symmetry axis but passing through the edge of the cylinder? (b) What is the moment of inertia (...
*March 17, 2012*

**trig**

In a computer simulation, a satellite orbits around Earth at a distance from the Earth's surface of 2.1 X 104 miles. The orbit is circular, and one revolution around Earth takes 10.5 days. Assuming the radius of the Earth is 3960 miles, find the linear speed (velocity) of ...
*March 17, 2012*

**Biology**

What is the role of promoter in lac operon?
*March 17, 2012*

**Physics**

Would it have been possible to make DNA a binary code?
*March 17, 2012*

**pre-calc**

Find an angle between 0 and 2ð that is coterminal with the given angle. -8pi/3 A sector of a circle has a central angle of 60°. Find the area of the sector if the radius of the circle is 3 mi.
*March 17, 2012*

**calculus**

Consider the function f(x)=3x^2 – 5x on the interval [-4,4]. Find the average slope of the function on this interval. By the mean value theorem, we know there exists at least one c in the open interval (-4,4) such that f’(c) is equal to this mean slope. For this ...
*March 16, 2012*

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