# Posts by David

Total # Posts: 2,308

Chemistry
How many grams of butane must be burned to provide the heat needed to melt a 85.0-g piece of ice (at its melting point) and bring the resulting water to a boil (with no vapourization)? Assume a constant pressure of 1 bar and use the following data: Hfo(H2O(g))=-241.83 kJ/mol, ...

Chemistry
Suppose you wanted to heat a mug of water (250 mL) from room temperature 25 C to 100 C to make a cup of tea. How much energy (in units of calories and joules) would you need from your microwave?

chemistry
If 50.0 g of Ba(CN)2 reacts to produce 12.9 g of HCN, what is the percent yield?

math
wats 460 miles and 20 gallons as a unit rate

Mathematics
Find a fraction which reduces to 3/4 when the numerator and denominator are each decreased by 1, and which reduces to 4/5 when the numerator and denominator are each increased by 1.

Mathematics
Find a fraction which reduces to 3/4 when the numerator and denominator are each decreased by 1, and which reduces to 4/5 when the numerator and denominator are each increased by 1.

Chemistry
CH4 + 2O2 -> CO2 + 2H2O When 70 grams of oxygen react with methane, how many liters of CO2 gas are produced?

PARALLELOGRAM WRITING A PROOF
Qaud KATE has vertices K(-2,1) A(0,5) T(6,7) E(4,3). Prove that KATE is a parallelogram.

English
What does the poem "America" by Maya Angelou really mean.? What is really try to say in this poem..???

English
well that's that kind of the problem because i seem to find no differences, to me they seem pretty much alike.!

English
what are some differences of the work of Walt whitman " I hear america singing" & Woody Guthrie " This land is your land"..?

English
Thank you!(:

English
wat does the song "This land is your land" by Woody Guthrie actually mean.? What is the significance of the song?

English
how can you compare and contrast Walt Whitman "I Hear America Singing" to John Mellencamp "Little Pink Houses".??

English
Thank you so much for the help, now i have a good idea of what to do now!

English
how can you compare and contrast Walt Whitman "I Hear America Singing" to John Mellencamp "Little Pink Houses".??

Social studies
What is an example of checks and balances

Physics
Is the maximum torque that a given force can exert on an object occurs when the force is applied to the axis of rotation. I think it is true because torque is always specific when it comes to the axis of rotation. Am I correct?

Physics
I would say it is true that the center of mass of an isolated system moves at a constant velocity, as long as there is a constant force applied to it. Am I correct?

geometry/calculus
Use Cavalieri's Principle to find the area of the region. In the example we see a "leaning tower" with base 'a' and height 'b'. The left side of the leaning rectangle is given by y = x^2, the right side given by y = (x - a)^2 the answer to this ...

Physics
True or False: If a sphere of mass M and radius R and a cylinder of mass M and radius R start rolling down a ramp from the same location at the same time, they both reach the bottom of the ramp at the same time.

Physics
True or False: If a cannon fires a cannonball in an easterly direction, the tendency of the cannon to move to the west is a result of the principle of conservation of energy.

Physics
True or False: If no friction forces are present the work done by a force on an object increases either its kinetic energy or its potential energy.

math-probability
betsy goes running 2 days out of 7 and james goes running 5 days out of 7. What is the probability that one of them is running on any given day.

geometry
A farmer has 30yd of fencing and wants to enclose an area beside his barn. What are the dimensions of the region of maximal area, and what is that maximal area if the region is an is isosceles triangle with its base along side of the barn. Given -> legs of length 15, x = 1/...

physic
23

chemistry
please, what is another name for double indicator titration and if the indicators are reversed is there any change in the result.

math
The ages of two children are 11 and 8years.In how many years time wil the product of their ages be 208

physics
if a tank was at 62 degrees farenhiet with a pressure of 14.7 psi. what would the presure be if the temperature rose to 178 degrees farenhiet?

math
X is a complex number. but X is not equal to 1. X^2011=1 Compute the sum X^(2n)/((x^n)-1) where n=1,2,3...2010

physics
Once a 28 kg crate is in motion on a horizontal ﬂoor, a horizontal force of 51 N keeps the crate moving with a constant velocity. The acceleration of gravity is 9.81 m/s. What is µk, the coeﬃcient of kinetic friction, between the crate and the ﬂoor

Physics
By what distance must two charges of +2 C and +10 C be separated so that the repulsive force between them is 3.70*10^10 N?

Physics
An iron ion contains 26 protons, 27 neutrons, and 23 electrons. What is the net charge of the ion?

Chemistry
help anyone?

Chemistry
the problem does not specify what the liquid is. that is part of my not understanding.

Chemistry
The osmotic pressure of a liquid at 320 K is 145 kPa. Calculate the freezing point of the solution.

Physics
If light in air is incident at 20°, at what angle is it refracted in glass?

Math
explain how you can use multdivide5 iplication to help you find 20 \\

Math
explain how you can use multiplication to help you find 20 divide by 5

chemistry
why is it necessary to make up to the 250 ml mark while during dilution?

Math problem
(a + b)/10 a = 68 b = 12 (68 + 12)/10 (80)/10 = 8

UNIVERSITY OF EDUCATION,WINNEBA
How would one use the elements of the marketing mix to advise a hairdresser?

Math
set up as a quadratic then solve for t 0=(8.98)t^2+55t-10 t=0.1767 seconds

Math
10ft

social studies
i to write a wellcome letter,wellcoming the new colonies to the United State and ease the fears

Physics
A small fish is dropped by a pelican that is rising steadily at 0.65 m/s. (Assume the positive direction is upward.) 1. After 2.5 s, what is the velocity of the fish? 2. How far below the pelican is the fish after 2.5 s?

science
what did galileo do in science that made him so famouse

physics
A mass m = 4.3 kg is attached to a vertical spring with k = 210 N/m and is set into motion. What is the frequency of the oscillation?

math
5th grade class of 16 students, one-half of the student arrived at school early, one-fourth arrived on time, and one-eighth arrived late. how many students were absent.

college algebra
use the given zero to find the remaining zeros of each function.g(x)=x^3+3x^2+25x+75;zero:-5i

math
Thanks, but that still makes no sense. If she SPENT a TOTAL of \$43 which included \$14 for socks and \$18.75 for a wallet and had \$4 LEFT, Why does the \$4 even have to be in the equation? \$43= \$14 + \$18.75 + LUNCH (X)

math
Why do you add the \$4? My daughter missed this on a homework sheet because she didn't use the \$4. Why should that even be considered?

math
Giselle spent a total of \$43 when she went shopping. She spent \$14 for socks, \$18.75 for a wallet, and bought lunch. When she got home, she had \$4 left. How much did she spend for lunch?

calculus
area of a semicircle is increasing at a constant rate. At 5 secs the area is 4pi. At 7 secs the area is 5pi. In terms of r at what rate is the radius changing?

OChem
A mixture of fluorene and benzoic acid is dissolved in diethyl ether and mixed thoroughly with an aqueous solution of NaOH. After the layers separate, what will each of the layers contain? Label the layers. Indicate the main components, not species that could be present in ...

Math
(9+8)*(7-6)*5+4*(3+2) = 105. You gotta add the parentheses first to get it to work. Remember that multiplication ALWAYS is done 1st.

Earth Science
It's not deposition ffs..

math
How can you divide m by 3 using an input and out put table?

university physics

English Literature
What pictures did the author leave in your mind? (Tell-Tale Heart)

English Literature
How do these words set the mood for the story? (The Tell-Tale Heart)

English Literature
What special words does the author use to help you see hear, smell, and/or taste things in the story- The Tell- Tale Heart by Edgar Allan Poe?

trig
To the nearest degree, determine the measure of angle X for each value of tan X a. tan X = 0.49 Just not sure how to solve these questions

ciencias
que planetas tendrian esas mismas manifestaciones

ciencias
que planetas tndrian esas mismas manifestaciones

Statistics
Given IQ~N(100, 256) find P(IQ > 115). Be certain to set your calculator to FLOAT 4 to match my answer exactly. I need to know how to figure this out on my calculator.... no one has taught me how to use my calc and I am so confused.... someone please help!

calculus
Find the points at which the following function is discontinuous.Indicate the intervals at which the function is continuous. f(x)= (x^2 if x<-1), (|x| if -1<x<=1), (3x+1 if 1<x)

6th
31,431,000 and this is the 23rd question in Saxon math course 1 😁 Hope I helped

I'm helping out my sister with her english homework and I am confused on what to do. Underline the independent clauses once and the dependent clauses twice. Circle the phrases. Our football team is proud because the team is undefeated. The part that i don't understand ...

CHEM - ASAPPP
write the equation for the reaction of fecl2 with k3[fe(cn)6]???

bio-assap
if there were two proteins samples of exactly the same concentration but one sample contained a protein having a significantly higher number of arginine and lysine residues compared to that of the other sample - would there be a difference in the amount of dye bound to each ...

math word problems
18+6=24 24-18=6 6x4=24 They both started off with 24 cards

engineering science
A ramjet is to propel an aircraft at Mach 3 at high altitude where the ambient pressure is 8.5 kPaand the ambient temperature T-node is 220 K. The turbine inlet temperature T is 2540 K. If all components of the engine are ideal - that is, frictionless - determine (a) the ...

simplify
Correct!

Math
Simplify. 4(c squared - 1) + 1/3c(3c+6)

Geometry
Write a two column proof. Given: angle STV is congruent to angle TVU, angle STU is congruent to angle UVS. Prove: Angle SVT is congruent to angle UTV.

Algebra
At noon, your family starts out .from Louisville to go to Memphis driving at 40 mi/h. Your uncle leaves Memphis to come to Louisville two hours later. He is taking the same route and driving at 60 mi/h. The two cities are 380 miles apart. At what time do the cars meet?

geometry
write a biconditional for: the moon is the largest satellite of Earth.

english
Can you explain why? I am horrible at english. You can contact me at 601-870-6672 Please someone help me understand this new english 12 stuff....

Math
Using formular express the equation. 5x2-6x-3=0

Physics
a rocket is launched at an angle of 53 degrees above the horizontal with an initial speed of 75m/s. It moves for 25 seconds along its line of motion with an overall acceleration of 25 m/s^2. What is its maximum height?

Math
Geometric Proofs.... Write a justification for each step Given: AB = EF, B is the midpoint of Line AC and E is the midpoint of Line DF. 1. B is the midpoint of Line AC and E is the midpoint of Line DF. 2. Line AB is congruent to Line BC and Line DE is congruent to Line DF 3. ...

Math
They both have the same amount of CD's. For minnie, 6 + 5 = 11 CD's For Amanda, 5 + 6 = 11 CD's So, 11 CD's = 11 CD's

Geometry
Geometric Proofs.... Write a justification for each step Given: AB = EF, B is the midpoint of Line AC and E is the midpoint of Line DF. 1. B is the midpoint of Line AC and E is the midpoint of Line DF. 2. Line AB is congruent to Line BC and Line DE is congruent to Line DF 3. ...

Chemistry
An object travels at a speed of 7500 cm/sec. How far will it travel in a day?

Geometry
The equation T = 0.03c + 0.05b relates the numbers of cans c and bottles b collected in a recycling rally to the total dollars T raised. How many cans were collected if \$147 was raised and 150 bottles were collected? Solve the equation for c and justify each step.

science
how many liters of oxygen will react with 124.5 liters of propane

SIGS FIGS
WHAT ARE SIG FIGS

Science

Physics
a worker drops a wrench from the top of a tower 90m tall. what is the velocity wgen the wrench strikes the ground?

Math
The organizers of of a walkathon get cost estimates from two printing companies to print brochures to advertise the event. The cost are given by the equations below, were C is the cost in dollars and N is the number of brochures. Company A: C = 15 + 0.10n Company B: C = 0.25n ...

Math
The organizers of of a walkathon get cost estimates from two printing companies to print brochures to advertise the event. The cost are given by the equations below, were C is the cost in dollars and N is the number of brochures. Company A: C = 15 + 0.10n Company B: C = 0.25n ...

Math Logic puzzle
A farmer has a goat, a wolf, and a cabbage. He wants to transport all three from one side of a river to the other. He has a boat, but it has only enough room for the farmer and one thing. The wolf willl eat the goat if they are left alone together, and the goat will eat the ...

math
i need to approximate profit in this equation 3. Hot Rocks Music sells CDs. If the profit can be approximated by following equation: , where x represents the number of thousands of CDs sold. Approximately, how many CDs must be sold in order for the company to make a profit?

MS. SUE HELP!
If 4.26 lb of chicken costs \$6.77, what would 3.75 lb cost? PLEASE HELP ME MS. SUE D: CAN U PLEASE EXPLAIN ME B4 GIVING ME THE ANSWER

algebra
are u a teacher?

algebra
THANK YOU SO MUCH!!!!!!!!!!!!!!!!!!!! I GET IT NOW!!!!!!!! =)

algebra
You make 20 silk flower arrangements and plan to sell them at a craft show. Each flower arrangement costs \$12 in materials, and your booth at the craft show costs \$30. If you sell the arrangements for \$24 each, how many must you sell to make at least \$100 profit?

chemistry
x = (Br-)- 0.10 how do you get the actual answer for that problem if there is no ksp for it?