Saturday

February 28, 2015

February 28, 2015

Total # Posts: 1,957

**Chemistry**

Can we use moles of HCl instead of B to calculate limiting reactant?
*February 27, 2015*

**Chemistry**

When 0.500 moles of boron trichloride react with 1.20 moles hydrogen gas to produce elemental boron and hydrogen chloride gas, the actual yield of boron was 66.4 % of the theoretical yield. The mass of boron obtained was _____ g. Please help I'm stuck on it.
*February 27, 2015*

**chemistry**

sodium burns in chlorine to produce sodium chloride according to the reaction: 2Na(s) + Cl2(g) = 2NaCl(s). A student is asked to predict the mass of sodium chloride produced when 71 g of sodium is placed in a container of 200 g of chorine. The container is heated until the ...
*February 23, 2015*

**S.S.**

what was "king" and the main topic of conversation in the south? politics sugarcane cotton slavery I was thinking COTTON was KING so C
*February 19, 2015*

**science**

can someone explain the life cycle of the animalia kingdom please
*February 11, 2015*

**physics**

a tsunami originating in japan has a wavelength of 10^5 m and a period of 10 mins. how long does it take to travel 8000km?
*February 11, 2015*

**Math**

The company needs at least $300,000 fire and theft insurance and at least $4,200,000 and liability for the from these plans. How many units should be purchased from H plan to minimize the cost of the premiums? What is the minimum premium?
*February 7, 2015*

**physics**

Four identical point charges (+2.51 nC) are placed at the corners of a rectangle, which measures 4.00 m by 7.00 m. If the electric potential is taken to be zero at infinity, what is the potential at the geometric center of this rectangle?
*February 6, 2015*

**Calculus 2**

wouldn't it be the integral of sqrt(1+u^2)du instead of integral u(sqrt (1+u^2)du because the du takes care of the outside u?
*February 4, 2015*

**Calculus 2**

integral of e^x(sqrt(1+e^(2x)))dx
*February 4, 2015*

**Calculus 2**

use the method of equating coefficients. integral of (x^3+5x^2+12)/((x^2)(x^2+4)) dx
*February 4, 2015*

**physics**

Air becomes conducting when the electric field strength in a region exceeds 3x106 V/m. if a spark jumps between a charged object and a grounded object when the two objects are 10 cm apart, what is the potential difference between the two objects? If a lightning strike is 4x103...
*February 2, 2015*

**Physics**

A hollow metal sphere has inner and outer radii of 20.0 cm and 30.0 cm, respectively. As shown in the figure, a solid metal sphere of radius 10.0 cm is located at the center of the hollow sphere. The electric field at a point P, a distance of 15.0 cm from the center, is found ...
*January 29, 2015*

**physics**

A +1.4-nC point charge is placed at one corner of a square (1.8 m on a side), and a -2.5-nC charge is placed on the corner diagonally opposite. What is the magnitude of the electric field at either of the other two corners?
*January 29, 2015*

**Math, Algebra**

I've done. y-(-3)=(5/2)(x-(-3)) y-(-3)=(5/2(-15/2) y=(5/2x)-(-15/2)+3 y=(5/2x)+(9/2) Is that correct?
*January 19, 2015*

**Math, Algebra**

I normally use point slope. I'm used to having to sets of points not just one.
*January 19, 2015*

**Math, Algebra**

Can someone help me figure this out for my review? Find the equation of the line that passes through (2,-3) and has a slope of (5/2)
*January 19, 2015*

**Chemistry (Error Propagation)**

Calculate, with uncertainty, and express with a reasonable number of significant figures. a) 5.4 (±0.2) – 3.7 (±0.4) = b) 6.84 (±0.04) × 0.7 (±0.04) =
*January 19, 2015*

**math**

The hire purchase price for a T.V set is made up of $4,000 deposit and 18 equal monthly installments of $1,200 each. Amos was given a discount of 20% on the hire purchase price on paying the cash for the T.V set. How much did he pay?
*January 17, 2015*

**Math **

A rectangle is 26 meters long and 18 meters wide.What is the length of the diagonal of the rectangle to the nearest meter? equation: A2 + B2= C2 I don't know where to put the numbers, but I think the answer may be 32. Thank you for any help!
*January 12, 2015*

**Chemistry (Acid-Base)**

I'm a tad confused by the question, The protonation constant for the acid HA has the value K=2*10^6. (a) what is the principal species at pH 6.00? (b) what is the principal species at pH 9.00? (c) what is the quotient [A-]/[HA] at pH 6.3 and 7.5?
*January 12, 2015*

**math**

adi, john ,and hailee plant seedlings in their neighberhood park. adi plants 40% of the total number of seedlings, john plants 45% of the total number of seedlings and hailee plants the rest of the seedlings.if hailee plants 87 seedliings how maany seedlings do they plant ...
*January 10, 2015*

**Math **

A certain infinite geometric series has first term 7 and sum 4. What is the result when the third term is divided by the second term?
*January 8, 2015*

**Geometry**

In rectangle ABCD, AC= 8x-10 and BD=2x+20. Find the length of BD
*January 3, 2015*

**Geometry**

So the answer is y= 2/3x +11 ?
*January 3, 2015*

**Geometry**

Find an equation of the line passing through the point (6,5) and perpendicular to the line whose equation is 2y+3x=6
*January 3, 2015*

**Math (PreCalculus)**

The second hand of a clock is 4 inches long. Describe the height of the tip of the second hand from the bottom of a clock. (The radius of the clock is 1 inch more than the length of the second hand.)
*December 24, 2014*

**AP Calc**

Find the value of c which satisfies Rolle’s Theorem for the function f(x)=sin(x²) on (0,√π).
*December 20, 2014*

**math**

Wanda bought a pair of jeans for 32.50. She can purchase a second pair doe 40% off the regular price. How much will she spend on two pair of jeans?
*December 19, 2014*

**Math **

Part (a): Find the sum a+(a+1)+(a+2)+.....+(a+n-1) in terms of a and n Part (b): Find all pairs of positive integers (a,n) such that n>= 2 and a+a+1)+(a+2)+....+(a+n-1)=100.
*December 15, 2014*

**Math **

Let a1,a2,......a10 be an arithmetic sequence. If a1+a3+a5+a7+a9=17 and a2+a4+a6+a8+a10=15 then find a1.
*December 15, 2014*

**Math **

Penn writes a 2013-term arithmetic sequence of positive integers, and Teller writes a different 2013-term arithmetic sequence of integers. Teller's first term is the negative of Penn's first term. Each then finds the sum of terms in his sequence. If their sums are ...
*December 15, 2014*

**Math **

Penn writes a 2013-term arithmetic sequence of positive integers, and Teller writes a different 2013-term arithmetic sequence of integers. Teller's first term is the negative of Penn's first term. Each then finds the sum of terms in his sequence. If their sums are ...
*December 14, 2014*

**Algebra **

Suppose that |a-b|+|b-c|+|c-d|+.......+|m-n|+|n-o|+............|x-y|+|y-z|+|z-a|=20. What is the maximum possible value of |a-n|?
*December 13, 2014*

**Algebra **

Suppose that |a-b|+|b-c|+|c-a|=20. What is the maximum possible value of |a-b|?
*December 13, 2014*

**Algebra: Reiny Correction **

It is the fiftieth term not the fifteenth so would it be t50=a+49d
*December 13, 2014*

**Algebra **

The second and ninth terms of an arithmetic sequence are 2 and 30 respectively. What is the fiftieth term.
*December 13, 2014*

**Algebra **

Evaluate [3.2]. It is a floor and ceiling function. Thanks.
*December 12, 2014*

**Abnormal Psychology **

I need help diagnosis this case for my abnormal psychology review. Mr. B is a 20-year-old male college student who was recently arrested for possession of marijuana, which was detected when he was stopped for un¬safe driving. He was charged with driving while intoxicated ...
*December 9, 2014*

**Chem-Diprotic Acid**

Ascorbic Acid is an organic diprotic acid, H2A, that is found in many natural materials. KA1=7.94x10^-5 and KA2=1.62x10^-12. If you start with a 0.75 M solution of H2A, what is the concentration of ALL species in the solition at ph=3.8? I have no idea how to even start this ...
*December 7, 2014*

**Math **

The quantity sqrt(45)- 2sqrt(5) +sqrt(360/2) can be expressed as sqrt(N), where N is an integer. Find N. * the whole fraction 360/2 is squarerooted.
*December 5, 2014*

**Math **

Solve for the positive value of x such that 3sqrt(x^2-4x+4)=16. The 3 is the small number next to the sqrt sign.
*December 4, 2014*

**accounts**

Diane Gobin is the founder and manager of Gobin's World. Diane has approached the local bank for a loan to expand her business. As part of the loan application, Diane was asked to prepare Financial Statements for the business. She prepared the following balance sheet and ...
*December 4, 2014*

**math**

A book store bought 160 copies of a book for $4,000. How much money will they loose if they give away 2 books. show in ratio table form. Every book costs $25 so the store would loose $50 but how do you put that in a ratio table?
*December 3, 2014*

**Physics**

A 10kg mass is located at the (1.00m)i + (2.00m)j + (2.00m)k. A 5kg mass is located at (-1.00m)i + (1.00m)j + (1.00m)k. (A) Determine the moment of inertia of this system about an axis through the origin parallel to the x-axis. (B) Determine the moment of inertia of this ...
*November 29, 2014*

**Brief Calculus**

Find the area of the indicated region. We suggest you graph the curves to check whether one is above the other or whether they cross, and that you use technology to check your answer. (Round your answer to four significant digits.) Enclosed by y = e^x, y = 2x + 1, x = −2...
*November 25, 2014*

**Brief Calculus**

Find the area of the indicated region. We suggest you graph the curves to check whether one is above the other or whether they cross, and that you use technology to check your answer. Between y = −x and y = −x^3 for x in [−1, 1]
*November 24, 2014*

**Chemistry: Sigma & Pi bonds**

How many sigma bonds and pi bonds are there in each of the following: CH2Cl2 C2H3Cl C5H6 C6N4
*November 19, 2014*

**english**

need help on writing science fiction short story?
*November 18, 2014*

**math**

I don't think my first response went thru...so reposting! Thank You Ms. Sue, for the answer to cubic inches (11/16/14). It also made me realize that I skipped the step of multiplying the dimensions by each other.
*November 18, 2014*

**algebra 1**

cube root of (-64x^8y^5) Is it -8x^2y times the cube of y^2?
*November 18, 2014*

**algebra 1**

cube root of (-64x^8y^5)
*November 18, 2014*

**GEOMETRY**

the coordinates of point T are given. The midpoint of ST is (5,-8). Find the coordinates of point S. 18) T(10,18)
*November 18, 2014*

**math**

Thank You Ms. Sue, for the answer to cubic inches. It also made me realize that I skipped the step of multiplying the dimensions by each other.
*November 16, 2014*

**math**

how many cubic inches in 7'8"L, 12'2"W, 10'1" tall? please show how you get to the answer. I added up the feet (7+12+10=29 ft) and multiplied by 12 inches (29x12=348 in), then added on the remaining inches (8+2+1=11, 348+11) to come up with an answer...
*November 16, 2014*

**Business Law**

Two brothers, Sam and Jim, were fighting over the division of their ancestral property. After ten years of legal battle, a frustrated Sam contacted a powerful politician who subjected Jim to extreme duress in order to make him sign a contract of assent in favor of Sam. When ...
*November 15, 2014*

**Physics**

A 4 kg mass and a 9 kg mass are being held at rest against a compressed spring on a frictionless surface. When the masses are released, the 4 kg mass moves to the east with a speed of 2m/s. What is the velocity of the 9 kg after the are released?
*November 12, 2014*

**question**

Mini Makers, a small manufacturer of action figures, is formulating a budget for next year's promotional activities. The company decides to budget $50,000 for promotional expenses (an amount equal to its nearest competitor's allotment.) Mini Makers is using the ____ ...
*November 10, 2014*

**Chemistry**

Thank You!
*November 10, 2014*

**Chemistry**

If a balloon containing 1000 L of gas at 50 degrees Celsius and 101.3 kPa rises to an altitude where the pressure is 27.5 kPa and the temperature is 10 degrees Celsius, its volume there is?
*November 10, 2014*

**Calculus**

Hello. I have a few questions from my study guide, that I need to know to study for my test. 1) x^(2/3)*((5/2)-(x) a) determine the ordered pairs of the local extrema of the function. Use the second derivative test. B) determine the ordered pairs of all inflection points of ...
*November 10, 2014*

**Physics**

A 4 kg mass and a 9 kg mass are being held at rest against a compressed spring on a frictionless surface. When the masses are released, the 4 kg mass moves to the east with a speed of 2m/s. What is the velocity of the 9 kg after the are released?
*November 9, 2014*

**Goverment**

If you could get the government to implement one policy what would it be? Can't be marijuana legalization.
*November 9, 2014*

**Physics**

A target lies flat on the ground 4 m from the side of a building that is 10 m tall, as shown below. The acceleration of gravity is 10 m/s2 . Air resistance is negligible. A student rolls a 4 kg ball off the horizontal roof of the building in the direction of the target. The ...
*November 7, 2014*

**Math**

Nathan is designing a box to keep his pet newt in. To make the box, he’s going to start with a solid rectangle and cut squares with sides x cm in length from each corner, as shown in the picture below. The dimensions of the of the solid rectangle are 51 cm by 45 cm. The ...
*October 30, 2014*

**Business**

1.The owners of Brownfield Machinery, brothers George and Robb, now in their late 50s, have decided to sell the business. No one else in the family is interested in taking over the business. Brownfield machinery has 11 employees and sales of $2.5 million in 2012.George and ...
*October 27, 2014*

**Business**

1. After operating for 10 years, Zipcar, earlier this year (2013), was bought for $500 million by Avis, a leader in the car rental industry. With the acquisition of Zipcar, Avis will now surpass its direct competitors, Hertz and Enterprise.The deal is expected to be finalized ...
*October 27, 2014*

**Chemistry**

what mass of precipitate will form if 1.5L of concentrated pb(clo3)2 is mixed with .55L of.190 M NaI
*October 26, 2014*

**Math**

Thanks for the help.
*October 25, 2014*

**Math**

Simplfy the following expression - 3x + 5x + y+y+y I think the answer is 8x + 3y Would I be right? Thank You
*October 25, 2014*

**statistics**

A professor is interested in determining whether assigning mandatory homework affects students’ grades. He is currently teaching two sections of the same class; in one class, he assigns mandatory homework problems, while in the second class, he just recommends homework ...
*October 24, 2014*

**statistics**

A health psychologist, who is interested in childhood obesity, thinks that there may be a relationship between daily television viewing and eating habits. Data is collected from 500 children; for each child, information is collected on the number of hours of daily television ...
*October 24, 2014*

**statistics**

Researchers investigated the effects of encoding conditions on subsequent memory for a list of words. Participants were assigned to one of three encoding conditions: 1) saw list of nouns they were asked to remember (word alone condition), 2) list of words was accompanied by a ...
*October 24, 2014*

**physics**

A 1075 kg van, stopped at a traffic light, is hit directly in the rear by a 705 kg car traveling with a velocity of +2.06 m/s. Assume that the transmission of the van is in neutral, the brakes are not being applied, and the collision is elastic. What is the final velocity of ...
*October 23, 2014*

**Math help**

Please answer this 1 question!! 1.Which could be the name of a point? A. EF B. k C. Q D. MN
*October 21, 2014*

**Chemistry**

Consider the following reaction. 2 HCl(aq) + Ba(OH)2(aq) BaCl2(aq) + 2 H2O(l) ΔH = -118 kJ Calculate the heat when 114.8 mL of 0.500 M HCl is mixed with 300.0 mL of 0.400 M Ba(OH)2. Assuming that the temperature of both solutions was initially 25.0°C and that the ...
*October 19, 2014*

**Physics**

A bullet is fired from a rifle that is held 2.5 m above the ground in a horizontal position. The initial speed of the bullet is 1450 m/s. Find: (a) the time it takes for the bullet to strike the ground and (b) the horizontal distance traveled by the bullet.
*October 17, 2014*

**Math 116**

Well, you could say: since every square is a rectangle 'because it is a quadrilateral with all four angles right angles,' therefore the area didn't change.
*October 14, 2014*

**Math**

hint exterior angle is 360, minus 120 subtract total degrees of triangle
*October 14, 2014*

**c programming**

string[] dDate = dob.Split('/'); string dDay = dDate[0]; string dMonth = dDate[1]; string dYear = dDate[2]; if (Convert.ToInt32(dDay) > 01) { if (Convert.ToInt32(dMonth) == 01 || Convert.ToInt32(dMonth) == 03 || Convert.ToInt32(dMonth) == 05 || Convert.ToInt32(...
*October 14, 2014*

**Chem**

If not all the alum dissolves in the water before adding the Ba(NO3)2 solution, what effect will this have on the sulfate percent error determination?
*October 12, 2014*

**Chemistry**

How much heat would you need to melt 20.0 L of ice that had frozen on a fruit tree.
*October 11, 2014*

**math**

2 times
*October 11, 2014*

**math physics**

you forgot gravity
*October 9, 2014*

**@someone who can show me how to do this**

*infinite
*October 9, 2014*

**@someone who can show me how to do this**

infinate if x=1, then 6(1)+y=-3 6+y=-3 move the six y=-3+(-6) y=-9 or if x=-2, then 6(-2)+y=-3 -12+y=-3 subtract the twelve and add to the other side y=-3+(--12) two neg = positive thus y=-3 + 12 y=9
*October 9, 2014*

**physics**

5ms+16=21ms initial velocity (io) the delta v(t)=(ending velocity-io)/total deceleration time = (t)f/s^2 Thus, change in velocity = a t 0-21 = (t)f/s^2 second to top = t and therefore: d = Vi t + (1/2) a t^2
*October 9, 2014*

**chemistry**

First, find out how many moles of hydrogen there are Then, use Avagadro's Constant to find out how many atoms there are.
*October 9, 2014*

**economics**

ps is the difference between the amount that producers actually receive and the minimum amount that they would have to receive in order to supply the given level of output. On a graph, ps can be shown as the area above the supply curve and below the prevailing market price.
*October 9, 2014*

**chemistry**

the actual mass (g) = Number of moles x Molar mass, or m = n x M Number of moles of solute = Concentration (mol. L) x Volume of solution (liters) -1 or n = C x V
*October 9, 2014*

**economics**

that should have been answered in your other question
*October 9, 2014*

**Chem 30 Thermodynamics**

your temperature increase -or decrease- is given by the specific heat (S) of the object. (s)pecific heat = (new temp)/mass*change in temp. or if youre crazy, calculate the actual change in temp = heat added/(mass x specific heat) and compare it to actual (known) heat capacity ...
*October 9, 2014*

**math**

Trick question...you have 9 blocks!
*October 9, 2014*

**physics**

Use the third equation of motion velocity to displacement Your initial velocity is 15m/s Your final velocity is 0m/s displacement is 0m substitute the values and solve time
*October 9, 2014*

**physics**

If you don't have laminar flow, then you need to figure Quadratic Drag, drag force is proportional to the square of velocity and to the cross-sectional area of the object. For which you'll need to id the correct Reynolds Number
*October 9, 2014*

**physics**

given laminar flow, the drag force is proportional to the radius of the sphere and to its velocity. Double the radius, double the drag force. Double the velocity, double the drag force. This is known as Stokes Drag
*October 9, 2014*

**physics**

Work=mgh
*October 9, 2014*

**pre calculus**

cscB - sinB = 1/sinB - sinB = (1 - sinB*sinB)/sinB = (1 - sin^2B)/sinB = cos^2B/sinB = cosB*(cosB/sinB) = cosB(cotB)
*October 9, 2014*

**math**

6500-2500=4000 4000/2=2000 2500+2000=4500 or 6500-2000=4500
*October 9, 2014*

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