# Posts by Lex

Total # Posts: 90

**Chem**

How many carbon atoms are contained in each of the following number of moles: (a) 1.40 mol; (b) 5.70 mol?

*February 17, 2017*

**math **

a guy wire is 15m long. it supports a vertical television tower. the wire is fastened to the ground 9.6m out from the base of the tower a) calculate the angle formed by the guy wire and the ground b) calculate how far up the tower the guy wire attacks

*January 20, 2017*

**chem**

A sample of oxygen at 32?C occupies 340 mL. If this sample later occupies 1064 mL at 57?C and 1.2 atm, what was its original pressure?

*November 30, 2016*

**science**

Potassium-40 has a half life of 1.2 billion years and decays into the stable daughter isotope Argon-40. If you find a rock that contains 20 Potassium-40 atoms and 60 Argon-40 atoms, how old is the rock?

*October 25, 2016*

**History**

Thank you!!! That means much to me, for taking your time in your life to respond to this. I'm sure of my answers now. :) Thank you again!!

*September 29, 2016*

**History**

1. Which region was home to the Sioux? • the Eastern woodlands of North America • Southern Mexico and Central America • the Pacific Northwest of North America • the Central plains of North America 2. Which represents an Aztec adaptation to their environment...

*September 29, 2016*

**physics**

A bead slides on the frictionless wire as shown in the figure attached. If the speed of the beead is 2.0 m/s when its at A, how fast will the bead be going at point B and at point C?

*September 22, 2016*

**Math**

Ohhh okay! Thank you! I got: 84.38, so yeah that makes total sense. Thanks!!

*May 12, 2016*

**Math**

If I have $135 and I put 3/8 of it away in savings, how much do I have left to spend? I tried doing division, but I got 360 and I can't think of any other equations..

*May 12, 2016*

**Math**

-10(-11) Would this be -110 ? I know a negative times a negative should be a positive but does this change when the second number is inside the ( )

*May 2, 2016*

**CHEM**

2H2+O2=2H2O H=-484KJ Which answer best describes the transfer of heat that occurs when 1.41 mol of H2 reacts with 0.671 mol of O2? 341 kJ released 484 kJ released 341 kJ absorbed 484 kJ absorbed 325 kJ released 325 kJ absorbed

*April 13, 2016*

**chemistry**

477848.3?

*April 13, 2016*

**chemistry**

When you add 0.567 g of sodium metal to an excess of hydrochloric acid, you find that 5890 J of heat are produced. What is the enthalpy of the reaction as written below? 2Na(s)+2HCl(aq)=2NaCl(aq)+H2(g)

*April 13, 2016*

**CHEMESTRY**

Calculate how many grams of O2(g) can be produced from heating 65.8 grams of KClO3(s).

*April 13, 2016*

**science**

Combining 0.280 mol of Fe2O3 with excess carbon produced 19.4 g of Fe.

*April 13, 2016*

**chemistry**

2H2O2(l)+N2H4(l)=4H2O(g)+N2(g)

*April 13, 2016*

**chemestry**

Given the following chemical equation, determine how many grams of N2 are produced by 9.72 g of H2O2 and 6.53 g of N2H4

*April 13, 2016*

**Math**

A fraction has a value 2/3. If 4 is added to the numerator and the denominator is decreased by 2, the resulting fractions have the value 6/7. What is the original fraction? (Let x be the numerator and y be the denominator)

*November 24, 2015*

**Organic Chemistry**

-1.85

*November 8, 2015*

**Math**

Find the value of k so that each trinomial is a perfect square 49d^2-56d+k

*November 1, 2015*

**AP world history help**

I. there was no painful initiation rite

*October 24, 2015*

**Science Help Plzz**

Thanks morgan!!

*June 2, 2015*

**Algebra. Help me please!**

Andrew decides to wait until age 65 to begin receiving social security benefits. Find the present value of his estimated $26,000 per year in payment assuming 6%per year and payment until his 90th birthday. A. $265,263.20 B. $322,3667.36 C. $338,082.42 D. $281,059.48 (Please ...

*April 23, 2015*

**math**

A woman added 376 ml of liquid gasoline additive to the 17.4L of gasoline in her car's tank. Find the total amount of liquid in the tank. There are now _L of liquid in the tank.

*November 29, 2014*

**Algebra**

The answer is B. 44 quarters+40 nickels=84 coins (0.25*44)=$11 (0.05*40)=$2 11+2=$13

*November 23, 2014*

**Calculus**

A rectangular field is to be enclosed by a fence and divided into three lots by fences parallel to one of the sides. Find the dimensions of the largest field that can be enclosed with 800 feet of fencing. Help me please!!!!!!!!!!! THANK YOU

*October 18, 2014*

**math**

The bottom portion of a loading bin is cone shaped. The base radius of this part of the bin is 3.5 feet and the slant height is 6.5 feet. What is the capacity and lateral surface area of this part of the bin? Round your answer to the nearest hundredth.

*April 24, 2014*

**computer science**

a) What is the largest positive number that can be represented in 12 bits using one’s complement? Represent the number in bits and decimal as well. Assume the first bit is the sign bit. (2 marks)

*March 23, 2014*

**CS programing**

Storage: .data 2 0 ; storage for n22 .data 2 0 ; temp storage 23 .data 2 2 ; constant 2 24 .data 2 2 ; const 2 25 0 10 ;const 10 26 please can u show me the correct way to declare a constant using wombat.(CPU sim).

*March 20, 2014*

**finance**

adams enterprises noncallable bonds currently sell for $1030. they have a 15 year maturity, an annual coupon of $85, and par value of $1000. what is their yeild of maturity? a) 9.53% b) 8.15% c) 8.88% d) 8.55 % e) 7.41%

*November 2, 2013*

**Math**

Kate Alexander worked 40 hours last week. Her pay rate is $8.50 per hour. Assuming 7.65% social security withholding, how much should her employer withhold from her check for social security?

*September 10, 2013*

**Algebra 2**

There are 2 leave along 3 in of an ivy vine. there are 14 leaves along 15 in of the same vine. How many leaves are there along 6 in of the vine?

*September 8, 2013*

**analytic geometry**

The segment joining (-1,4), (2,-2) is extended three times its own length. Find the terminal points.

*July 14, 2013*

**math**

What is the portion if the base is 900 and the rate is 12 3/4?

*May 14, 2013*

**Physics**

Anyone please?

*May 11, 2013*

**Physics**

Two large, parallel, conducting plates are 20 cm apart and have charges of equal magnitude and opposite sign on their facing surfaces. An electrostatic force of 3.0 10-15 N acts on an electron placed anywhere between the two plates. (Neglect fringing.) a) Find the magnitude of...

*April 27, 2013*

**math 115**

C(x)=450x+5000, R(x)=-3x^2+900x for 20<x<150 where x>=20

*April 26, 2013*

**Physics**

I meant to say the negative sign in the equation. And Thank you very much.

*April 25, 2013*

**Physics**

So because of the negative sign in the question would the answer end up being negative?

*April 25, 2013*

**Physics**

17. Potential due to a point charge: What is the electric potential 17.0 cm from a 3.50 μC point charge?

*April 25, 2013*

**Physics**

17. A 5.6 kg toy race car moves along an x axis. The diagram below shows the force acting on the car. (The vertical axis is marked in increments of 2 N.) a) What is the momentum of the car at t = 9.0 s b) What is the car's velocity at t = 9.0 s? The graph has the following...

*April 18, 2013*

**Physics**

A 9 kg hanging weight is connected by a string over a pulley to a 5 kg block sliding on a flat table. If the coefficient of sliding friction is 0.2, find the tension in the string.

*April 15, 2013*

**math**

Thank u don't understand fractions yet sue... u r so kind

*April 10, 2013*

**math**

5/9

*April 10, 2013*

**math**

Martha sees 9 animals in the pet store..4rabbits an 5 cats...what fraction shows how many cats

*April 10, 2013*

**math**

We have four apples I eat one what fraction shows how many apples are left

*April 10, 2013*

**chemistry**

3. Based on your answer in question 2, determine the percent error of your calculated specific heat capacity value of your unknown metal using the specific heat capacities of known metals below. Metal Specific Heat Capacity Nickel 0.440 Tin 0.210 Silver 0.237 Magnesium 0.140 ...

*April 4, 2013*

**physics**

As your hand moves back and forth to generate longitudinal pulses in a spiral spring, your hand completes 3.26 back-and-forth cycles every 8.31 s. The velocity of the pulse in the spring is 1.47 cm/s.

*March 24, 2013*

**deutsch**

schwarm heisst gruppe

*March 24, 2013*

**English 1/ or literature**

What is a example of a understatement in the cask of amontillado.? I know a understatement is a form of speech which contains an expression of less strength than what would be expected. I really need help with this. Thanks :)

*January 28, 2013*

**health**

it's b

*November 2, 2012*

**chemistry**

Porassium alum is 3.9 parts per 100 parts of water. Knowing this, how many moles of potassium alum are present in 50ml?

*October 19, 2012*

**health**

Hell yeah son!

*August 11, 2012*

**chemistry**

I'm not 100% sure but try this. Heat(vap) = Delta H (gas) - Delta H (liquid). Doing that I got 42kj/mol.

*July 18, 2012*

**math**

Tom made pieces of string that were 5/6 yards long. He made 30 pieces. How many yards did he intially have?

*May 29, 2012*

**Geometry**

An isosceles triangle has area of 125 ft2. If the base is 14 ft, what is the length of each leg? Round your answer to the nearest tenth.

*May 25, 2012*

**English - Poetry**

I'm doing a Tritina style poem for my English class and I'm doing the envoy now but I'm not sure how I could use the 3 words: twinkle/twinkling, rosy, and sleepy. And it has to relate to babies and the bond between them and their mothers and emotional stuff like ...

*May 24, 2012*

**english**

Well, I'm guessing American and English are alike because Americans speak English as far as I know... Lol.

*May 24, 2012*

**English HELP.**

My topic for my pursuasive essay in English is "Dogs are Smarter than cats", I need legitimate facts about this because whenever I do research it only shows "facts" without good resources or they're just biased, from most of my google searches. I'd ...

*May 21, 2012*

**Geometry/Math again!**

The base of a prism is a regular hexagon that measures 4 cm on each side. The prism has a height of 13 cm. What is its total surface area?

*May 21, 2012*

**Geometry**

A rectangular pyramid fits exactly on top of a rectangular prism. Find the volume of the composite space figure if the prism has length 19 cm, width 2 cm, height 11 cm, and the pyramid has height 7 cm.

*May 21, 2012*

**Geometry/Math**

Calculate the volume to the nearest tenth of a 6.3-m cube with a hole 2 m in diameter drilled through it. Use 3.14 for pi.

*May 21, 2012*

**Chemistry**

What is a glucose molecule structure made up of? Is it: oxygen, hydroxl ions, hydrogen ions, and carbon bonds? I'm not good at this, is this even close to being right?

*March 22, 2012*

**Physics**

1.728J

*March 13, 2012*

**RIDDLE**

Mara because the letter i is not there-Lex

*November 24, 2011*

**math**

the expression 6 times radical 20 divided by 3 times radical 5 is equvilent to 1. 3 radical 15 2. 2 radical 15 3. 8 4. 4

*October 19, 2011*

**I'm in desperate need of h**

I'm in desperate need of help for a huge titration lab and finding the molarity. if I give you the problem could you help?

*April 29, 2011*

**College algebra**

suppose you invest 2500 and earn 4.2% annual interest, compounded quarterly. how long will it tak for your investment to double?

*March 7, 2011*

**science**

The turntable below is spinning. Which coin has a greater speed than the penny? a. the dime b. the quarter c. The penny is moving faster than both of the other coins. c. All three objects are moving at the same speed. pennyis closest to center dime in middle quarter on outer edge

*February 13, 2011*

**science**

When the electrons are aligned in the magnetic domains of two materials,what occurs- what is it called

*February 12, 2011*

**science**

true or false:: When the electrons are aligned in the magnetic domains of two materials, magnetization can occur.

*February 12, 2011*

**science**

penny is closest to center, dime is halfway,quarter is on the outer edge

*February 12, 2011*

**science**

if you place a dime penny and quarter on a spinning turntable which coin has a greater speed than the penny than the penny

*February 12, 2011*

**science**

Max turns the handle on a pencil sharpener. This turns the wheel that turns the blades. The blades sharpen the pencil. In this situation, what is the input force?

*February 12, 2011*

**physics**

Which type of wave would be beneficial to a surfer?

*February 11, 2011*

**science**

if you have a 343 J of kinetic energy at the lowest point of a pendulum's swing and at the highest point has a height of 5 m what is the pendulum's mass

*February 11, 2011*

**geometry**

Given that AB is a tangent of the circle with the center at X, AB = 12, and XD = 2.5, which is the length of DB?

*January 19, 2011*

**spanish**

what is "Nada menos que todo un hombre" about?

*December 29, 2010*

**spanish**

what does: Les piden uds mas tarea a los profesores? mean

*December 29, 2010*

**College Algebra**

14 billion

*November 17, 2010*

**us history**

How were the governors of the Pennsylvania colony chosen?

*September 27, 2010*

**chemistry**

no that's not right

*July 13, 2010*

**MATH: PROBABILITIES**

You need to use the rule of BAYES and the theorem of total probability.

*April 24, 2010*

**3rd grade**

when subtracting 288 from 506 how would thinking of 500 as 50 tens help you?

*January 19, 2010*

**algebra**

x^2+4x/5x^3+20x^2 * 10x-40/x^2-16

*October 20, 2009*

**trig**

I need help on these problems: Find the exact value of tan(23pi/6) also, Find the reference angle in radians and degrees for (34pi/18) please help walk me through these.

*October 4, 2009*

**math**

wwhat is the answer to x+7y=14

*July 26, 2009*

**Chemistry**

Bacterial digestion is an economical method of sewage treatment. The reaction 5CO2(g) + 55NH4+(aq) + 76O2(g) --bacteria--> C5H7O2N(s)[bacterial tissue] + 54NO2-(aq) + 52H2O(l) + 109H+(aq) is an intermediate step in the conversion of the nitrogen in organic compounds into ...

*August 27, 2008*

**French**

The difference between tous and tout is rather simple, and I'm afraid that you didn't get the answer you were looking for in the previous response. If not..I hope this helps: Tous is the plural of tout! And toutes is the plural of toute. Good luck!

*November 12, 2007*

**Grammar**

When learning pronoun case (subjective pronoun,objective,possessive) do I need to just memorize the list? I am having trouble identifying them. Any help please. I am in 5th grade. I recommend memorize, using homemade flash cards. It wont take long to memeorize these. Clue: Any...

*February 14, 2007*

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