Posts by anonymous

Total # Posts: 114,110

Chemistry
So if it is the reverse of equation 2. You would have to take ?H°1 - ?H°2?

Chemistry
What is the process to calculate ?H° for the reaction? O2(g) + 2NO(g) --> N2O4(g) O2(g) + 2NO(g) --> 2NO2(g) ?H°1 N2O4(g) --> 2NO2(g) ?H°2 a) ?H°1 + ?H°2 b) ?H°1 - ?H°2 c) ?H°2 - ?H°1 d) ?H°1 - 2?H°2 I know according to Hess...

PHYSICS
1.How does a flip work? pretend your on a trampoline and jump vertically. How can you jump up in the air and flip.Where is the force coming from to give you a torque? 2.Do you add up linear momentum and rotational momentum for a net momentum? Like energy?

Math
Nine less than the product of 23 and Gail's age

Chemistry
According to kinetic-molecular theory, particles of an ideal gas a) are motionless b) have zero masses c) attract each other d) have negligible volumes

Chemistry
Determine the starting mass of each reactant if 46.3 of K3PO4 is produced and 92.8 of H3PO4 remains unreacted. 3KOH + H3PO4 ----> K3PO4 + 3H2O

Chemistry
Determine the starting mass of each reactant if 46.3 of K3PO4 is produced and 92.8 of H3PO4 remains unreacted. 3KOH + H3PO4 ----> K3PO4 + 3H2O

trig ratios'
Consider one guy wire. Let x be the height at which the guy wire is attached to the tree. sin58 = x/10 x = 10sin58 ft Tree height = 10sin58 + 2 = ____ ft

physics
A tube that is open on both ends is 4 meters long. Assuming that the speed of sound is 340m/s, find the following: a) What is the wavelength of the fundamental standing wave (the first harmonic) b) What is the frequency of the fundamental wave? c) What is the frequency of the ...

physics
A string is vibrated with a wave that has a wavelength of 6 meters. How long is 1 loop of the standing wave?

physics
A ship is anchored in a bay. The echo of the ship's foghorn, reflected from an iceberg, is heard 5.0 seconds after the horn is sounded. The temperature of the air is -10.0 degrees Celsius. How many meters away is the iceberg? Show your work.

physics
What frequency would a listener hear if a train moves away from the listener at 180 km/hr? The frequency of the horn is 3500 Hz, and the air temperature is 19.0 degrees Celsius. Show work, and include 3 significant figures.

physics
You push back and forth on a 5 m high flagpole and make it sway back and forth. When you push it with a frequency of 2 Hz you get it into its fundamental standing wave. a) How fast do the waves travel through the flagpole? b) What frequency would you have to apply to get it ...

Maths
Cylinder A is eight time as tall as cylinder B, but the diameter of cylinder B is four times the diameter of the cylinder A. Which cylinder has larger volume? How many times as large ?

algebra
Remove the parentheses from the following expression, and combine like terms: 3(ax + b2 â€“ c) + 2

Biophysics
Consider the flow of blood through a large horizontal artery with 1.0 mm of diameter. The artery has a smooth reduction to an artery 0.5 mm in diameter. If the pressure of the blood in the larger artery is 8.00 x 104 Pa and the pressure in the smaller artery is 6.00 x104 Pa, ...

Algebra
Can you please help me on this question for Algebra: Write the word that the number 32/33 represents. From this word, take out the opposite of the word that means you get three strikes in baseball. Now unscramble the remaining letters to get what 12 is to 108 or 7 is to 49. ...

Science
A cyclist speed up at a constant rate from rest to 8m/s to 6s. Find the acceleration of the cyclist

Maths
I mean its like a rectangular prism but with squares as the base

Maths
There are no typos but a square prism is a rectangular prism

Physics
I'm trying to find the relationship between electric field strength and distance from point charge as an equation. I found the equation cd = E/(c*c). c is the factor by which the distance changes and E is the field strength. Is the equation good enough?

trigonometry
Rewrite 4sin(x)-5cos(x) as Asin(x+phi)

Chemistry
How much heat is absorbed when a 35.0 g aluminum block increases in temperature from 23°C to 33°C? Specific heat of Al: 0.900 J*g-1*°C-1 q=ms?T q=(35.0 g)(.900)(33°C - 23°C) q= 315 J? Just making sure there isn't anything that I am missing.

Chemistry
Which response presents ions in order of increasing atomic radius? a) smallest Cl-, K+, Na+ largest b) smallest Cl-, Na+, K+ largest c) smallest K+, Na+, Cl- largest d) smallest Na+, K+, Cl- largest I would assume the answer would be D since the electrons are more tightly ...

Chemistry
What volume of 0.200 M K2C2O4 is required to completely react with 30.0 mL of 0.100 M Fe(NO3)3? 2Fe(NO3)3 + 3K2C2O4 --> Fe2(C2O4)3 + 6KNO3

Chemistry
Which electron transition in a hydrogen atom will emit a photon with the longest wavelength? n = 2 to n = 1 n = 3 to n = 1 n = 1 to n = 2 n = 1 to n = 3 I would assume it would be a short electron transition since energy and wavelength are inversely related. But I am a little ...

dascxasx

English
a sense of fear gushed throughout my body does it make sense?

math
well first of all: 1/3 log (ab)^3 = (1/3)(3) log (ab) = log (ab) now log (ab) = log a + log b (that is how your slide rule works) (you do not have a slide rule?) (google slide rule :) so what we have here is x+y

physics
Radiant emittance is R=?T? The solar radiation power is N=RS?=?T?4?(r?)², where S? is the Sun surface, and r? is the Sun radius. The power radiated by the Sun falls on the inner surface, which radius is equal to the distance from the Sun to the Earth - r?. This area is ...

Chemistry
Which element is oxidized and which element is reduced in this redox reaction? CO2(g) + H2(g) --> 2CO2(g) + H2O(g) Is Oxygen oxidized and hydrogen reduced?

Chemistry
What is the net ionic equation form the reaction between Na2S(aq) and Pb(HCO3)2(aq)? Just wanting to make sure this correct: 2Na+(aq) + S2-(aq) + Pb2+(aq) + 2HCO3-(aq) --> 2Na+(aq) + 2HCO3-(aq) + PbS(s)

Chemistry
What mass of NO2 is formed by the complete reaction of 2 mol O3 with excess NO in the reaction? O3 + NO --> O2 + NO2 I know the molar mass of O3 is 48 g/mol and NO2 46 g/mol a) 23.0 g b) 46.0 g c) 92.0 g d) 96.0 g

Chemistry
What is the empirical formula for a compound of sodium and oxygen that contains 59% by mass? I am guessing it would be NaO because the molar mass of Na is 22.99 g/mol and 22.99 g/mol Na / 22.99 + 16 is approx 59%. Just wanted to make sure that is correct.

Chemistry
Okay, that makes since. The % amount of hydrogen in water is going to stay the same no matter how many grams of water you have.

Chemistry
Would it be 5.560%?

Chemistry
A 10.000 g sample of water contains 11.19% H by mass. What would by the %H in a 20.000 g sample of water? I got 22.38%, would that be correct?

Chemistry
Which compound has the highest lattice energy? a) CaO b) LiF c) MgO d) NaF I am guessing B because Lithium has the lowest energy level?

Chemistry
An unknown metal, m, forms an ionic compound with the formula, M2S3. Which formula represents the compound formed by the metal with oxygen? a) MO b) MO2 c) MO3 d) M2O3

Chemistry
HI is formed from the overlap of a hydrogen 1s orbital with an iodine 3p orbital? is that correct? I am having trouble with the iodine orbital, thank you.

Calculus
Consider the differential equation dy/dx = 2x - y. Let y = f(x) be the particular solution to the differential equation with the initial condition f(2) = 3. Does f have a relative min, relative max, or neither at x = 2? Since we're trying to find a max/min I don't ...

Chemistry
Total area = 5.0 x 101 x 2.10 m^2 =_____m^2 Total solar power falling on heliostats = 1420 W/m^2 x _____ m^2 = ______W 26700 W * 100 / ______W = ______% efficiency.

Math
I added from a and b 3+2=5 and the 4 was left then added =4=9. I really didn't know what I was doing your right I just didn't know =4 was left it was just a guess

Math
That's all information they gave me.

Math
So the answer would be 31 -13 _____ 18

Math (integrals) (Substitution)
=- ? (4-u)sqrt(u) du =- ? (4-u)u^(1/2) du ***= -4?u^.5du + ?u^1.5 du ***= -4(u^1.5/1.5) + u^2.5/2.5 + c ***= -(8/3)u^(3/2) + (2/5)u^(5/2)+c we disagree about sign of second term =- ? 4u^(1/2) - u^(3/2) du =-4? u^(1/2) - u^(3/2) du =-4((2/3)u^(3/2) - (2/5)u^(5/2)) =-4((2/3)(4-x...

typo
VOLTAGE = I R sin wt

physics
7.75 * 1.414 If current = I sin wt and current = I R sin wt then power = I^2 R sin^2 wt average of sin^2 = (1/2) so average power = (1/2)I^2 R = Irms^2 R so I^2 = 2 Irms^2 and as we said to start I = sqrt(2) Irms = 1.414 Irms

physics
The rms output in a circuit is 7.75 A. What is the maximum current?

Math
time on bus = (5/60)hr = (5/60)(60) = 5 minutes so he walked for 20 inutes 20 minutes (1 hour/60 min) = (1/3)hr 2 km/(1/3)hr = 6 km/hr

Math
Yumi walked 2 km to a bus stop to catch the bust to school. The bus arrived straight away and averaged 60km/h for the 5km trip. Yumi's total travelling time was 25 minutes. at what average speed did Yumi walk to the bus stop? The answer is 6, but the only thing I could ...

Physics
An electron moves to the left with a velocity of 3.2 x 10^5 m/s and has a magnetic force of 5.6 x 10^-17 N exerted on it. What is the magnitude of the magnitude field? Assume the charge has a value of 1.60 x 10^-19 C.

Social Studies
How do nearby businesses with similar products usually compete? (1 point) A. offering deals and low prices B. changing to different product types C. lowering the level of service to save costs D. establishing a minimum price for everyone to use

geometry
Lateral area does not include the base, so we want the total area of just the four triangles that make up the other faces. These triangles are isosceles and congruent to one another, since this square pyramid is regular. Draw one of these isosceles triangles and label it with ...

algebra
Let n be the number of nickels. Let q be the number of quarters. n + q = 34 0.05n + 0.25q = 3.90 Solve the above system of equations for n and q.

Chemistry
9.54 for this one?

Chemistry
The resulting pH of a solution when 100 mL of 0.877 M NH3 is mixed with 100 mL of 0.481 M HBr is ___. For NH3, Kb = 1.8 × 10?5.

Chemistry
Does 4.7 sound correct?

Chemistry
A solution that is prepared by mixing 20.0 mL of 0.32 M HC2H3O2 with 20.0 mL of 0.36 M NaC2H3O2 would have a pH of ___. For HC2H3O2, Ka = 1.8 x 10-5.

Social Studies
I NEED HELP QUICK!!!! what effect did John Hay's open door policy letters have on the imperial powers of Britain France Germany Russia and Japan? 1. it provoked the imperial powers to declare war on the United States. 2. it caused the imperial powers to restrict trade in ...

Social Studies
what effect did John Hay's open door policy letters have on the inperial powers of Britain France Germany Russia and Japan?

language arts
Can someone help me with unit 3 lesson 19 different perspective test plz

Math
Im sorry for bombarding you guys with questions. I've only needed help with 3 of 40 so far.. Anyways, moving on! 3! = 3 * 2 * 1 4! = 4 * 3 * 2 * 1 5! = 5 * 4 * 3 * 2 * 1 30! = 2^x * N where N is odd. What is the value of x? I have no idea where to start, but reading the ...

Math
1/3 * 2/4 * 3/5 * 4/6 * 5/7 *... ... ... * 98/100 = ? Is there a specific way on how to calculate this?

La
1. B

Math
Yeah, my bad. Thanks a lot!

Math
Dedi has a rectangular pool in his backyard. The surface area of the pool in 30m^2 and the width is 5m. There are 4 lights, equally spaced along each of the longer sides of the pool, including a light at each corner. What is the shortest distance between two lights? I tried ...

english
A successful academic argument depends upon

Math
Is it #1

math
Verify: tan^2a=cot^2a-cot^2acsc^2a

Math
Verify: tan^2a=sec^2a tan^2a-1

Statistics
50 apples from an orchard are randomly selected. A mean apple diameter of 2.22 inches is calculated with a margin of error for a 95% confidence interval of ±0.13. What is the interval estimate of the population mean? 1.99 < ? < 2.23 2.09 < ? < 2.35 2.09 <...

Calculus
A particle's position along the x-axis is given by x(t) = t^4/24 - t^3/2 + 2t^2 - 1. What is the maximum acceleration on the interval 0 <= t <= 4? I found the acceleration to be (t^2 - 6t + 8)/2 and the derivative of the acceleration to be t - 3. I thought the ...

Calculus
A differentiable function called f(x) achieves its maximum when x=0. Which of the following must then be true? 1. The function p(x) = xf(x) has a critical point when x = 0. 2. The function m(x) = (f(x))^2 has its maximum at x = 0. 3. The function j(x) = f(x^2) has its maximum ...

Algebra 2
I'm so sorry!! I actaully meant f(x)=2sin(x/2)-1

Algebra 2
What effect does changing the function f(x)=2sin(x2)?1 to the function g(x)=2sin(x)?5 have on the graph of f(x)? The graph is stretched vertically by a factor of 2 and shifted right 4 units . The graph is compressed vertically by a factor of 2 and shifted left 4 units . The ...

EXAM TOMORROW
Building new,stable houses and shops

history
Barry allan is correct and yes he spelled his name wrong if he did mean the flash but that doesent matter is is correct

Math
Divide (-6m^9 - 6m^8-16m^6) / 2m^3 I get -3m^12 -3m^11 - 8M^9 NOT A CHOICE ON PAPER could it be -3m^9 -3m^8 -8m^6

physics
the half life of radium is 1600 years of 100 grams of radium existing now 25 grams will remain after how many years

Math
950,000*.10 = 95,000 950,000-95,000 = 855,000 (1yr) 855,000*.10 = 85,500 855,000-85,500 = 769,500 (2yr) Repeat the process until reach 5 yrs.

social
How did social controls shape Japanese identity and citizenship?

Geometry
Find the area. The figure is not drawn to scale. 6.9 4cm

english
1. is writing 2. we playing 3. is 4.otherwise 5none of these 6. none of these 7. does 8. would 9. monkeys 10. wives 11. have watched 12. played 13. loves 14. meets 15 inputted 16 given 17 sisters-in-law 18 furnitures 19 mary's and jane's 20 its

english
1. is writing 2. we playing 3. is 4.otherwise 5none of these 6. none of these 7. does 8. would 9. monkeys 10. wives 11. have watched 12. played 13. loves 14. meets 15 inputted 16 given 17 sisters-in-law 18 furnitures 19 mary's and jane's 20 its

How does the aggregate expenditure multiplier change given a decrease in marginal propensity to import and marginal propensity to consume?

Economics
Explain how each will impact the size of autonomous expenditure multiplier, other variables constant. (a) Decrease in marginal propensity to consume (b) Decrease in marginal propensity to import

Chemistry
A copper electrode weighs 35.42 g before the electrolysis of a CuSO4(aq) solution and weighs 36.69 g after the electrolysis has run for 20.0 min. What was the amperage (Amps) of the current used? this is the equation that i used is it correct (1.27g Cu x 1 mol Cu x 2 mol e- x ...

geometetry
Given: KLMN is a trapezoid, m?K = 90°, LM = 9, KN = 18, MN = 15 Find: Area of KLMN LM and KN are parallel

statistics
Suppose that diastolic blood pressure readings of adult males have a bell-shaped distribution with a mean of 84 84 mmHg and a standard deviation of 9 9 mmHg. Using the empirical rule, what percentage of adult males have diastolic blood pressure readings that are greater than ...

Geometry
Given: KLMN is a trapezoid, KL = MN, m?LKM=m?MKN, LM:KN = 8:9 , Perimeter KLMN = 132 LM and KN are parallel Find: The length of the legs. I reposted this question because the last time was not vary clear, and I got 49 but it is wrong

Music
What is the note called that has 4 beats?

geometry
P stands for the perimeter, and LM and KN are parallel. angle one is LKM and angle 2 is MKN

geometry
Given: KLMN is a trapezoid, KL = MN, m?1=m?2, LM:KN = 8:9 , PKLMN = 132 Find: The length of the legs. I got 49, but it was wrong

bio
salt does it have more free enrgy when dissolved in water

Work
i am primarily cream in color but speckled in grey. round is not my shape, nor is square. i am a loner in my environment. if i could speak, the stories i would tell.

English
What two word are the most opposite in meaning hanker grovel hurtle and patronize

Chemistry
A system has an initial energy of 117 joules. The energy equation includes --40.1 J of heat and -20.3 J of work. What is the final energy? Was heat added to the system or to the environment? Was work done by the system or to the system? Be sure to show all of your work and ...