Thursday

July 31, 2014

July 31, 2014

Total # Posts: 404

**chemistry**

how would you separate a mixture of NaCl, Fe pellets and water

**Chemistry**

Complete the electron dot structure below to show how beryllium flouride (BeF2) is formed. F F Be+ -> Be F F

**Chemistry**

What is the coordination number of the ions in a face-centered cubic crystal? In a simple cubic crystal?

**Chemistry**

Write the symbol and electron configuration for each ion and name the noble gas with the same configuration. a. nitride _________________________ b. oxide ___________________________ c. sulfide _________________________ d. bromide _________________________

**Chemistry**

How many electrons will each element gain in forming an ion? a. Nitrogen ______ b. Oxygen ________ c. Sulfur _______ d. bromine _______

**Chemistry**

Why do beryllium and flouine combine in a 1:2 ratio?

**Chemistry**

Complete the electron dot structure below to show how beryllium flouride (BeF2) is formed. F F Be+ -> Be F F

**Precalc/Trig Word Problem**

From the top of a 200-ft lighthouse, the angle of depression to a ship in the ocean is 23 degrees. How far is the ship from the base of the lighthouse?

**Word Problem**

In a certain individual the resting diastolic pressure at time t is given by B(t)= 80+7sin((pi)(t)/(12)) where t is measured in hours since midnight and B(t) in mmHg (millimeters of mercury). Find this person's pressure at 6:00 am, 10:30 am, noon, and 8:00 pm.

**Precalculus/Trig 6**

Find the exact value of the following trigonometric functions: sin(13pi), cos(14pi), tan(15pi)

**Precalculus/Trig 5**

Find the exact value of thet following trigonometric functions: tan(5pi/6) tan(7pi/6) tan(11pi/6)

**Precalculus/Trig 3**

The degree measure of an angle theta is 40 degrees. What is the radian Measure of theta? at what point P does the terminal ray intersect the unit circle (what is the ordered paid P(____, ___)?

**Precalc/Trig 2**

The point P lies in the 4th quadrant and is located on a circle of radius 2. Find the missing coordinate for P. (___, (negative square root of 3)).

**Precalc/Trig 1**

What equation would you use to show that the point ((square root of 11)/(6), (5/6))is on the unit circle?

**math**

65 men 75 women are enfolled in calculus. There are 30 business majors, 40 biology majors, 50 computer science majors, and 20 mathematics majors. No person has a double. If a single calculus student is chosen, find the probability that that the student is not a mathematics major

**Physics**

A ball is thrown downward at 12.3 m/s. How much time does it take for it to reach the ground, 182.6 m below?

**Physics**

A student drops a rock off a bridge. The rock has a mass of 5.81 kg. If the bridge is 48.7 m high, how much time does it take it to reach the water below?

**Math**

What compound polygon has 28cm and area 48 cm

**Precalculus SOH CAH **

how are the following relations true? S(theta + pi/2) = C(theta) and C(theta + pi/2) = -S(theta)?

**math**

You do 14500 times .09 then you add that to 14500 to get year 1 then repeat that till you get 22309.51.or something close to that.

**Derivatives (check answer)**

Let y=x^5 - pi^5. Find dy/dx My answer is 5x^4 because pi^5 becomes 0? Am I correct?

**Algebra (Please check)**

Number 1 I know is D

**Algebra (Please check)**

PLEASE CHECK MY ANSWERS (: I just want to make sure I am doing this correctly __________________________________ Graph the system of constraints and find the value of x and y that maximize the objective function. Constraints: x ≥ 0 y ≥ 0 y ≤ (1)/(5) x + 2 5 &...

**Algebra (Need help desperately)**

Thanks :D I'm 90% sure number 1 is D, but do a good way how I could do 2 or 3? If you dont mind explaining to me?

**Precalculus **

he distance between 2 points (x1,Y1) and (x2,y2) is given by d = square root (x1-x2)^2 + (y1-y2)^2 a - pick 2 arbitrary points in 3 dimensions, (x1, y1, and Z1) and (x2,y2,z2) and plot these points. Not that there are 90 degrees between the xy, xz, and yz axes. b- using your s...

**Precalculus**

The distance between 2 points (z1,Y1) and (x2,y2) is given by d = square root (x1-x2)+ (y1-y2)^2) a - pick 2 arbitrary points in 3 dimensions, (x1, y1, and Z1) and (x2,y2,z2) and plot these points. Not that there are 0- degrees between the xy, xz, and yz axes. b- using your sk...

**Calculus (Check)**

This seems to easy. Check please. Find. Lim (x^2)-4 x->2 e I substitute in 2 (2^2)-4 e gives me 4-4 e So my answer is e^0 or 1.

**Calculus with Analytical geometry**

I'm stumped on this one. lim |x-1|sin(1/x-1) x->1

**Calculus**

Thank you, I see where I made my error now. X^2 over x^2 becomes 1. I cancelled them out.

**Calculus **

Check my work please? Determine if f(x)= (x^2-3x+2)/(1+x^2) has a horizontal asymptotes. If so, give the equation. So I took x^2 and divided everything by it. (x^2/x^2)-(3x/x^2)+(2/x^2) / (1/x^2)+(x^2/x^2) Cancelled out some x's and have -(3/x)+(2/x^2) / (1/x^2) Now as x a...

**Precalculus**

how are the following relations true? S(theta + pi/2) = C(theta) and C(theta + pi/2) = -S(theta)?

**Precalculus**

Find the distance along an arc on the surface of the earth that subtends a central angle of 1 minute. (1 minute = 1/60 degree) This is a nautical mile. Note that the radius of the Earth is 3960 miles and there are 1760 yards in a mile. Express your answer in both miles and yards.

**Chem I**

Ammonia is composed of H and N in a ratio of 9.33g N to 2.00g H. If 4.56g N combine completely with H to form ammonia, how many grams of ammonia would be formed? How do you calculate this?

**Chemistry**

Calculate the mole fraction of glucose (C6H12O6) in a solution which contains 15g of glucose in 100 g of H2O.

**Chemistry**

For the reaction IO3– + 5I– + 6H+ 3I2 + 3H2O the rate of disappearance of I– at a particular time and concentration is 2.8 x 10-3 M s-1. What is the rate of appearance of I2 in molarity per second?

**Chemistry**

A buffer is prepared by transferring equal concentrations of the components of the conjugate pair, C6H5COOH and C6H5COONa, into a beaker. What is the approximate pH of the buffer? (Ka = 6.5 10–5) a) 2.81 b) 4.19 c) 7.00 d) 9.81 e) 11.19

**Chemistry**

how does a formula of Iron(III) and ethylenediamine, assuming a coordination number of 6 look and what is it's name and written transition metal formula

**Chemistry**

how does a fomula of Iron(III) and ethylenediamine, assuming a coordination number of 6 look and what is it's name?

**Chemistry**

Ammonia is a stronger ligand than is the chloride ion. What does this statement mean?

**Math**

A square is made up of section A and section B. Section A is 500 sq. ft. and section B is 750 sq. ft. What percent of the square is section A?

**chemistry**

Calculate the solubility of Cacl2 in g/L based on the experiement. Given 650g of CaCl2 added to 1.0L and allowed to dissolve as much as possible. While the remaining solid CaCl2 is filtered out of the solution and found to have a mass of 5.509g. What is the solublity of CaCl2

**trig**

y=92.5 x=157.9 x+y=250.4ft

**trig**

y=92.5 x=157.9 x+y=250.4ft

**ALG 2 (exponents)**

Write log'2' 8 = 3 in exponential form?

**Algebra 2**

How would I find the sum of the geometric series given? 1/5 - 1/25 + 1/125

**Math**

You need to line the inside of a tank that is 6 ft. diameter and 40 ft. high. You are going to line only the sides with the lining. How many sq. ft. are needed?

**Chemistry**

How much heat is either ______(absorbed or given off) when 91.45g of HI decomposes to H2 and I2 at 25 degrees C? What goes in the blank and how much heat? Thanks!

**Algebra 2 (Geometric Series)**

Write (2x+3y)^3 in expanded form I need a little help as far as how I would begin working this problem out.

**Algebra 2 **

Find the inverse of the following function: f(x) = 3x + 12 I don't think I worked this problem off correctly...I am suppose to find the inverse of the function Is this the correct way to work this problem? y= 3x + 12 x= 3y + 12 3y = x - 12 f-1(x) = x - 12/3

**Algebra 2 (Quadratic Equations)**

Is the point (-3, -2) a solution of the intersection of the following set of quadratic equations: Y < -X^2 X^2 + Y^2 < 16 I'm not sure how to actually work this problem out. Can anyone help me with this problem please.

**Geometric Series (Algebra 2)**

Thank you Damon, that helped alot...

**Geometric Series (Algebra 2)**

I need some assistance or a formula when trying to find the first term of geometric series please! I don't understand this!!!! What is the first term of a geometric series with a summation of 289, 5 terms and a common ratio of 1/2?

**Algebra 2**

Thank you, I think I understand how to work it out now! That helped me out so much!

**Algebra 2**

What is the first term of a geometric series with a summation of 800, 4 terms and a common ratio of 3?

**Algebra 2**

What is the first term of a geometric series with a summation of 800, 4 terms and a common ratio of 3?

**government**

idk what this stuff is im doing it on germany

**government**

Using the Internet, encyclopedia, and/other reference material for research, write a 1,000-word report on feudalism in the history in one of the following countries: •France •England •Germany Include the approximate years when feudalism began and ended in that c...

**physics**

A pair of eyeglass frames are made of an epoxy plastic (coefficient of linear expansion = 1.30 10-4°C−1). At room temperature (20.0°C), the frames have circular lens holes 2.27 cm in radius. To what temperature must the frames be heated if lenses 2.28 cm in radiu...

**physics**

A hypodermic syringe contains a medicine with the density of water (figure below). The barrel of the syringe has a cross-sectional area of 2.44 10-5 m2. In the absence of a force on the plunger, the pressure everywhere is 1.00 atm. A force vector F of magnitude 1.91 N is exert...

**physics**

For safety in climbing, a mountaineer uses a nylon rope that is 65 m long and 1.1 cm in diameter. When supporting a 94-kg climber, the rope elongates 1.4 m. Find its Young's modulus.

**physical aspects of nature**

A 1,440-N crate is being pushed across a level floor at a constant speed by a force of 250 N at an angle of 20.0° below the horizontal; (a) What is the coefficient of kinetic friction between the crate and the floor? (b) If the 250-N force is instead pulling the block at a...

**Math**

A swimming pool is 40 feet long, 20 feet wide, 8 feet deep at the deep end, and 3 feet deep at the shallow end; the bottom is rectangular. If the pool is filled by pumping water into it at the rate of 40 cubic feet per minute, how fast is the water level rising when it is 3 fe...

**Economics**

Wilpen Company, a price- setting firm, produces nearly 80 percent of all tennis balls purchased in the United States. Wilpen estimates the U. S. demand for its tennis balls by using the following linear specification: where Q is the number of cans of tennis balls sold quarterl...

**chemistry**

KI+H2SO4+KIO3 Write the balanced net ionic equation.

**Algebra 2**

How did you come up with that answer, I would like to learn how to work it out.

**Physics (verification)2**

I would love for someone to please verify my solution for this problem: A former amusement park attraction consisted of a huge vertical cylinder rotating rapidly around its axis. The rotation speed should be sufficient for the people found inside to be stuck to the wall when ...

**Physics (verification)**

I would love for someone to please verify my solution for this problem: A former amusement park attraction consisted of a huge vertical cylinder rotating rapidly around its axis. The rotation speed should be sufficient for the people found inside to be stuck to the wall when t...

**physics**

my bad, drwls is right, didn't take for account that it's around the rink, so there's the centripetal acceleration to take for account

**physics**

no, because he is at a constant speed, whenever you have a constant speed there is no acceleration

**physics**

A former amusement park attraction consisted of a huge vertical cylinder rotating rapidly around its axis. The rotation speed should be sufficient for the people found inside to be stuck to the wall when the floor was removed. what should be the minimum speed of rotation for t...

**media and american culture**

Do you think the Internet has created more harm than good to artists in the music industry? Explain your answer.

**media and american culture**

Do you think the Internet has created more harm than good to artists in the music industry? Explain your answer.

**Math**

Which lines are parallel? y=-3x+1 -3x+y=5 2y=-6x+12

**Chemistry**

@DrBob22 I think you would be of more help if you actually answered the question instead of just giving the equation in all your posts.

**English**

I have retyped the paragraph with a few corrections that I felt were necessary. Along with the tension that goes on between Mr. and Mrs. Bennet, Charlotte and Mr. Collins' marriage is not all happy giddy. Charlotte is considerably old for a single woman at the time and bec...

**geometry**

The moon is the largest satelite if and only if its for the earth.

**algebra**

where do the brackets go 2 x 3 to the 3rd power + 4 to = 4374

**math**

it just says domain R. I guess all real numbers?

**math**

find all values of c such that f(x) = (x+1)/(x^2+2cx+4) has domain R

**Quantitative Methods in Business**

I'm having trouble with this word problem: Priority Mail is the U.S. Postal Service's alternative to commercial express mail companies such as FedEx. An article in The Wall Street Journal presented some interesting conclusions comparing Priority Mail shipments with the...

**math**

in the quadratic formula ax©÷+bx+c, what does the "a" stand for in ax©÷?

**4th grade math**

44th

**Algebra**

During the first part of a trip, a canoeist travels 98 miles at a certain speed. The canoeist travels 10 miles on the second part of the trip at a speed 5 mph slower. The total time for the trip is 3 hours. What was the speed on the FIRST part of the trip? What was the speed o...

**Algebra**

Aki’s Bicycle has determined that when x hundred bicycles are built, the average cost per bicycle is given by C(x)=-0.2x^2-0.1x+9.743, where C(x) is in hundreds of dollars. How many bicycles should the shop build to minimize the average cost per bicycle? They should build...

**mathm**

how do you find the absolute maximum of 2x^3+3x^2-12x-7 on interval (-3,0)

**Physics**

A ball initially moving at 0.5m/s rolls down a straight slope, accelerating at 0.25m/s^2 for 4 sec, how far does the ball travel in this time?

**british lit**

what does the Redcrosse Knight represent in The Faerie Queene?

**Math - Properties of Logarithm **

Thanks... got it...

**Math - Properties of Logarithm **

Can someone show how to this question. Loga(x+3) + Loga(x-3) = 3 I don't know if I'm typing this correctly the a is the base. So, I'm thinking, Loga((x+3)(x-3)) = 3 (x+3)(x-3) = 3^a x^2 - 9 = 3^a, x^2 = 3^a + 9 x = sqrt(3^a + 9) but now I'm stuck, I don't k...

**Math**

Solve the system of equations by graphing. Then classify the system.x+y=8x-y=-2

**english**

how do I correctly punctuate ? "Who wants dessert?," Latisha asked us as she walked into the room with a beautiful steaming apple pie. or is it correct?

**Math**

A man has 2 pennies, 3 nickels, 1 dime and 2 quarters. How many different sums of money can he make using one or more of these 8 coins?

**Math**

Circle C has radius 4 inches. Circle D had radius 9 inches. These two circles are connected. Point A,B,and E are points of tangency. Find AB. From point C to point D(which is the radius of circle C plus the raduis of circle D) it is 13 inches. From point C to point A (radius o...

**Math**

I dont understand someone help me!!

**chemistry**

Does a precipitate form if HCl and Ba(NO3)2 are mixed?

**english**

Every now and then, instead of using e-mail, mail a letter to your grandparents. We live in a fast-paced world. We feel comfortable using computers to send e-mails and Instant Message. Nana doesn’t live in that time zone. Forget all those fancy fonts and emoticons or abbr...

**chemistry**

A 375 g sample of well water is found to contain 17.0 mg of lead. How much lead (in parts per million) is in the well water? Round to the nearest tenth. Don't forget the unit.

**bca**

____ is the code of acceptable behaviors users should follow while on the Internet; that is, it is the conduct expected of individuals while online.

**9th grade math**

the triange is 31cm, side 1 and side 2 have equal lenghts, while side 3 is one centimeter shorter than twice then length of side 1, how long is each side?

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