# Posts by Lex

Total # Posts: 91

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

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

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?

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?

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!!

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...

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?

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

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..

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 ( )

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

chemistry
477848.3?

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)

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

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

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

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

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)

Organic Chemistry
-1.85

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

AP world history help
I. there was no painful initiation rite

Science Help Plzz
Thanks morgan!!

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 ...

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.

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

Algebra 1B
You both are Wong smh

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

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.

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)

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).

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%

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?

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?

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

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

Physics

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...

math 115
C(x)=450x+5000, R(x)=-3x^2+900x for 20<x<150 where x>=20

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

Physics

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

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...

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.

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

math
5/9

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

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

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 ...

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.

deutsch
schwarm heisst gruppe

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 :)

health
it's b

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

health
Hell yeah son!

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

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

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.

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 ...

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

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 ...

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?

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.

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.

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?

Physics
1.728J

RIDDLE
Mara because the letter i is not there-Lex

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

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?

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

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

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

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

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

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

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?

physics
Which type of wave would be beneficial to a surfer?

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

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?

spanish

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

College Algebra
14 billion

us history
How were the governors of the Pennsylvania colony chosen?

chemistry
no that's not right

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

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

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

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.

math
wwhat is the answer to x+7y=14

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 ...

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!

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...