# Posts by David

Total # Posts: 2,261

**chem**

Fish-liver oil is a good source of Vitamin A. When 0.1232 g of fish liver oil is dissolved in 500. mL of solvent, an absorbance of 0.724 is recorded. When 0.00167 g of Vitamin A is dissolved in 250. mL of solvent, an absorbance of 1.018 is recorded. Calculate the mass percent ...

**Physics**

An electron (mass m = 9.11e-31 kg) is accelerated in the uniform field E (E = 2.00e4 N/C) between two parallel charged plates. The separation of the plates is 1.10 cm. The electron is accelerated from rest near the negative plate and passes through a tiny hole in the positive ...

**Algebra**

(-6,-5/2)and(-5/2,infinity)

**chemistry**

All I know is, nitrogen in fertilizer can embed the water table and change the pH, which then becomes toxic as it reaches the Gulf (In the US). Might start with that.

**Science**

1.08x10^21 atoms in 1%(w/v) aqueous KOH 1.63x10^21 atoms in 1% (w/v) aqueous HCL I would say more particles "in" the base, than particles "in" the acid.

**Math**

Refer back to Week One Discussion and use the names and ages of yourself and the other two people you selected. Make sure one is older than you and one is younger than you. In years, how old was the older person when you were born? Write an equation that models how old in ...

**math**

-2x-15=30

**math**

2X5^1/2

**geometry**

1/2 b h=30 1/2(2x+2)(x)=30 x^2+x-30=0 (x+6)(x-5) x=-6 Does not make sense x=5 2x5 +2 =12 Base 12 height 5

**Chemistry**

Marcus is right, Josie. I don't really understand it either but he is correct.

**college algebra**

-23/40 To get answer Subtract both sides by 1/3 Multiply both sides by 3/2 Subtract 5/4 from both sides Divide by 2 D=- 23/40

**Chemistry-DrBob222**

Arrows disappeared from below added them back to the equations. ??(a) I don't understand ln(No/N)=akt Is (a) -3.77 The decomposition of IBr(g)into I2 (g) and Br2 (g) is first order in IBr with k = 0.00255/sec. (a)Starting with [IBr] = 1.50M, what will [IBr] become after 2....

**chemistry**

how many grams of ethenol do i need to burn in excess oxygen in order to recover 5.0 g of h2o in a 75% yield

**geometry**

francisco designed a triangular garden surrounded by three square gardens. the area of garden c (the largest garden) is 400 sq. ft. and the length of a side of garden b is 12 ft. find the lengths of all sides of the triangular gardens and find the areas of the gardens. draw a ...

**Com 220**

How does the author of “A Nation Apart” organize information to build his argument? He organizes the information by first presenting problems of China's economic issues. He then goes on to show you some statistics from his sources and quotes the leaders that play...

**joe has a mass of 50 kg and sally has a madphysics**

joe has a mass of 50 kg and sally has a mads of 30 kg. they sit in class with a separation of 0.5 meters. Find hhe gravitational attraction between joe and sally

**Precalc**

First divide 500 from both sides Leaving e^.3x=1.2 Take ln e^.3x=Ln1.2 .3x ln e^.3x=ln1.2 (note:ln e=1 .3x=ln 1.2 x=(ln 1.2/.3) x=.60774

**algebra**

8.775 x 10^-1

**Algebra**

c^4/a^4 I believe is the answer

**Algebra**

I am trying to solve (2*(c^4)*2*(a^6))/(2*(a^10)) but the answer I am getting is 2c^4a^4. Do you know if this is correct?

**ChemistryDrBob222**

Arrows disappeared from below added them back to the equations. ??(a) I don't understand ln(No/N)=akt The decomposition of IBr(g)into I2 (g) and Br2 (g) is first order in IBr with k = 0.00255/sec. (a)Starting with [IBr] = 1.50M, what will [IBr] become after 2.50 minutes? (...

**ChemistryDrBob222**

Arrows disappeared from below added them back to the equations. The decomposition of IBr(g)into I2 (g) and Br2 (g) is first order in IBr with k = 0.00255/sec. (a)Starting with [IBr] = 1.50M, what will [IBr] become after 2.50 minutes? (b)How long, in minutes, will it take for [...

**Algebra**

Distance formula 1=((x-0)^2 +(x^3-0)^2)^1/2 1=(x^2+x^6) 0=x^6+x^2-0 Use x=1 and x=.5 Use bisection method to continue to the nearest tenth x=.83 and y=.83^3=y=.56 The points are -.83,-.56,.56,and .83

**Algebra**

Use the bisection method or a graphing calculator to find the coordinates of the two points on the graph of that lie r = 1 unit from the origin. Give the result to the nearest hundredth, I just need a direction to go on this problem

**calculus**

Use the bisection method or a graphing calculator to find the coordinates of the two points on the graph of that lie r = 1 unit from the origin. Give the result to the nearest hundredth, I just need a direction to go on this problem

**Algebra**

y=-1/3 x+8 y-7=-1/3(x-4) y=-1/3 x +25/3

**physics**

Suppose 3 mols of neon (an ideal monatomic gas) at STP are compressed slowly and isothermally to 0.19 the original volume. The gas is then allowed to expand quickly and adiabatically back to its original volume. Find the highest temperature attained by the gas. Find the lowest...

**Algebra 1**

Answer The two even sides are 135 And the shorter side is 45

**algebra**

Distance=Rate/time 50(Time)=32(Time + 2 hours)+17 50 x t = 32t + 64 +17 50t = 32t +81 50t-32t=81 18t=81 t=4.5 Plug this in to the origional equation 50(4.5)= 225 miles to New York Check answer 32(4.5 +2)+17=225 I hope this clears up this problem for you

**Algebra**

First to find slope -8--6/(-4)-(-1) = slope 2/3 Substituting y-(-8)=2/3 (x-(-4) y=2/3x-16/3

**Pre-Algebra**

On a trip from Lousiana to Flordia, your family wants to travel at least 420 miles in 8 hours of driving. Write and solve an inequality to find what your average speed must be.

**Math Geometry**

The angle bisector of one angle of a triangle forms two angles that measure 27 degrees. The angle bisector of another angle forms two angles that measure 34 degree. What is the measure of the third angle of the triangle?

**Math Geometry**

A right triangle has one angle that measures 16 degrees. What are the measures of the other two angles?

**phoenix**

o Find a movie review in an online publication for a movie currently playing in theaters. Post the link to the review for the class and provide five examples of how the reviewer used adverbs and five examples of the use of adjectives. Has the reviewer used them effectively? ...

**Chemistry**

The decomposition of IBr(g)into I2 (g) and Br2 (g) is first order in IBr with k = 0.00255/sec. (a)Starting with [IBr] = 1.50M, what will [IBr] become after 2.50 minutes? (b)How long, in minutes, will it take for [IBr] to go from 0.500M to 0.100M? (c)What is the half-life for ...

**Chemistry**

The decomposition of IBr(g)into I2 (g) and Br2 (g) is first order in IBr with k = 0.00255/sec. (a)Starting with [IBr] = 1.50M, what will [IBr] become after 2.50 minutes? (b)How long, in minutes, will it take for [IBr] to go from 0.500M to 0.100M? (c)What is the half-life for ...

**Physics**

An airplane must reach a speed of 185 mi/h to take off. If the runway is 467 m long, what is the minimum value of the acceleration that will allow the airplane to take off successfully? m/s2 I have been trying the formula vf^2=Vi^2+2AD and solving for A SO my work has been 185...

**physics**

E= 2.5 X 10^5 N/C

**Chemistry**

The decomposition of IBr(g)into I2 (g) and Br2 (g) is first order in IBr with k = 0.00255/sec. (a)Starting with [IBr] = 1.50M, what will [IBr] become after 2.50 minutes? (b)How long, in minutes, will it take for [IBr] to go from 0.500M to 0.100M? (c)What is the half-life for ...

**physics**

Two cars start from rest at the same location and at the same instant and race along a straight track. Car A accelerates at 6.6 fps2 to a speed of 90 mph and then runs at this constant speed. Car B accelerates at 4.4 fps2 to a speed of 96 mph and then runs a a constant speed...

**College Accounting**

Apr. 1 Cash $40,000.00 Capital $40,000.00 Apr. 4 Land $30,000.00 Cash $30,000.00 Apr. 8 Advertising $1,800.00 Accounts Payable $1,800.00 Apr. 11 Salaries $1,800.00 Cash $1,800.00 Apr. 13 Prepaid Insurance $1,500.00 Cash $1,500.00 Apr. 17 Drawing $1,000.00 Cash $1,000.00 Apr. ...

**physics**

A certain spring stretches 5.3 cm when it supports a mass of 0.65 kg . If the elastic limit is not reached, how far will it stretch when it supports a mass of 10 kg ? Answer in cm

**Physics**

Some enterprising physics students working on a catapult decide to have a water balloon fight in the school hallway. The ceiling is of height 3.2 m, and the balloons are launched at a velocity of 12 m/s. The acceleration of gravity is 9.8 m/s2 . At what angle must they be ...

**physics**

Some enterprising physics students working on a catapult decide to have a water balloon fight in the school hallway. The ceiling is of height 3.2 m, and the balloons are launched at a velocity of 12 m/s. The acceleration of gravity is 9.8 m/s2 . At what angle must they be ...

**Physics**

A certain spring stretches 5.3 cm when it supports a mass of 0.65 kg . If the elastic limit is not reached, how far will it stretch when it supports a mass of 10 kg ?Answer in units of cm

**physics**

You place a box weighing 302.1 N on an in- clined plane that makes a 35.6 angle with the horizontal. Compute the component of the gravita- tional force acting down the inclined plane. Answer in units of N.

**Algebra**

Hi. I am having some problems with substitution method and i just can't seem to get these right. I have 1. 2x - 3y = -1 with y = x-1 2. -4x + y = 6 with -5x- y = 21 and finally, 3. -5x + y =-3 with 3x -8y = 24

**Algebra**

Hi. I am having some problems with substitution method and i just can't seem to get these right. I have 1. 2x - 3y = -1 with y = x-1 2. -4x + y = 6 with -5x- y = 21 and finally, 3. -5x + y =-3 with 3x -8y = 24

**math**

a christmas tree is 34 feet tall. it casts a shadow 24 feet long. toms christmas tree is standing beside the tree at rockefeller center and is 5 feet 8 inches tall. how long of a shadow would toms tree cast?

**psychology**

the paralysis was the unconscious way of dealing with his impulse (id) to hit his father?

**4th grade**

Nick had 1 3/4 gallon of milk. How many pints of milk does Nick have.

**algebra**

the solution to the system of equations y= 2x and y = -x + 3 is a)2,1 b)(-1,2) c)2,-1) d)(1,2)

**algebra**

thank you gabby!!!!!!!!!!!!

**algebra**

the solutions to the system of equations y= 2x and y =-x + 3 is a)2,1 b)(-1,2) c)2,-1) d)(1,2)

**12th grade**

one type of probability used everyday is: a)experienced probability b)scientific probability c)frequency of occurence d)none of the above

**math**

when you put something in parenthesis like C(25,8) what does that mean or how do you solve it?

**Math**

Suppose you are managing 25 employees, and you need to form three teams to work on three different projects. Assume that all employees will work on exactly one team. Also, each employee has the same qualifications/skills, so any employee can serve on any team. The number of ...

**Algebra**

x = 0.5 4x = 2 4(0.5) = y - 1 +1 on both sides... y = 3! Thanks!

**Algebra**

I know but wouldn't you have to go through confusing fractions and multiply by fractions to get a whole number of x? I am trying to follow the teachers directions which do not include fractions.......

**Algebra**

Slove each system by substitution. 4x = y - 1 6x - 2y = -3 I have already attempted this problem and couldn't figure out what I should do. I came out with 4x + 1 = 3x + 1.5 I think this looks right because our teacher told us that for this specific problem that we should ...

**physics**

Ffg

**physics**

1.) A vertical spring with a spring constant of 450 N/m is mounted on the floor. From directly above the spring, which is unstrained, a 0.30 kg block is dropped from rest. It collides with and sticks to the spring, which is compressed 2.5 cm in bringing the block to a ...

**physics**

A string has a linear density of 8.5*10^-3 kg and is under the tension of 280 N. The string is 1.8 m long, is fixed at both ends, and vibrating in the standing wave pattern. What is the speed, length, and frequency?

**physics**

1.) The average sound intensity inside a busy neighborhood restaurant is 3.*10^-5 W/M^2. How much energy goes into each ear (area = 2.1 * 10^-2 m^2) during a one hour meal? 2.) A member of an aircraft maintenance crew wears protective earplugs that reduce the sound intensity ...

**physics**

The length of a simple pendulum is 0.79m and the mass of the particle at the end of the cable is 0.24 kg. The pendulum is pulled away from its equilibrium position by an angle of 8.5 degrees and released from rest. Assume that friction can be neglected and that the resulting ...

**physics**

1.) A vertical spring with a spring constant of 450 N/m is mounted on the floor. From directly above the spring, which is unstrained, a 0.30 kg block is dropped from rest. It collides with and sticks to the spring, which is compressed 2.5 cm in bringing the block to a ...

**algebra**

Find the mean for each set of data. Round to the nearest tenth if necessary. 12, 20, 8, 15, 16, 14, 7, 5, 11, 8, 14 a. 11.8 b. 13.2 c. 9.9 d. 10.4 My answer a)11.8

**Calculus**

prove that out of the rectangles under the curve = e raised to the power of -xsquared on the x axis and upper vertices on the curve, the one has the largest area the two upper vertices of which are exactly at the points of inflection of the curve.

**engineering science**

The power in a resistor RLOAD of 10 Ω when connected to a 100 volt supply is measured using a voltmeter and ammeter. There are two possible ways of connecting the meters as shown in FIGURE 2. The resistances RA and RV represent the internal resistances of the ammeter and ...

**trigonometry**

equation of circle passing through P(10,3), Q(11,8), and R(7,14).

**Math**

7

**math**

what is a slope intercept?

**chemistry**

in outo engine whith no pollusion controls, about 5% of the fuel(assume 100%actane c8H18)is unburned .calculate the mass and volume ratio of Co to C8H18 in exhaust gas? 2C8H18+17O2 =16CO+18H2O

**Chemistry**

Which of the following electron configurations is not consistent with Hund's rule? 1) 1s^2 2s^2 2p^2 3s^1 2) 1s^2 2s^2 2p^6 3s^2 3p^5 3) 1s^2 2s^2 2p^6 3s^3 3p^6 4) 1s^2 2s^2 2px^2 2py^1

**Chemistry**

Which of the following electron configurations is not consistent with Hund's rule? 1) 1s^2 2s^2 2p^2 3s^1 2) 1s^2 2s^2 2p^6 3s^2 3p^5 3) 1s^2 2s^2 2p^6 3s^3 3p^6 4) 1s^2 2s^2 2px^2 2py^1

**Physics**

An aluminum cylinder with a density of 2.70 g/cm3 has a volume of 3.8 ¡¿ 10-5 m3. If the cylinder is suspended from a scale and immersed in an unknown fluid, the scale reads 0.581 N? What is the specific gravity of the fluid?

**college chemistry**

Being that FeO has a metal in it and a pretty strong bonding force, I would say Iron(II)Oxide. CO2 is low, H2O is 0 degrees Celsius, and sugar is relatively low as well.

**geometry**

francisco designed a triangular garden surrounded by three square gardens. the area of garden c (the largest garden) is 400 sq. ft. and the length of a side of garden b is 12 ft. find the lengths of all sides of the triangular gardens and find the areas of the gardens. draw a ...

**physics**

wow. that was simple. thank you.. i should read the question more carefully next time :D

**physics**

A 52 g mountain climber, start from rest, climbs a vertical distance of 730 m. At top, she is again at rest. In the process, her body generates 4.1*10^6 J of energy via metabolic processes. Her body acts like a heat engine with efficiency ( W/Q_h.) W is the magnitude of work ...

**science**

. What must happen in order for a sound wave to form? A. An electric current must flow. B. A certain frequency must be reached. C. Matter must vibrate. D. Volume must be absorbed.

**Algebra**

This is about direct variation. The area a painter can paint varies directly with the amount of time he works. One morninig, he painted 204 ft² between 8 a.m. and 12:15 PM. Write a direct variation equation to describe the area y covered in x hours. The forumlua for ...

**Algebra**

This is my third question about direct variation. For this problem, tell whether each relationship is a direct variation. Explain. x | -1 | 5 | 8 | y | -1.5 | 7.5 | 12 |

**Algebra**

This is question 2 about direct variation For this problem, tell whether each relationship is a direct variation. Explain. x | 8 | 0 | -5 | y | 13 | 5 | 0 |

**Algebra**

For this problem, tell whether each relationship is a direct variation. Explain. x | -3 | -6 | -9 | y | 18 | 36 | 54 | My teacher didn't really explain direct variation very well, but i did catch that you put x over y. (Hopefully this helps)

**chemistry**

I worked it out to need 8458.6K would this seem like resonable value? thank you for you're help

**chemistry**

I think charles law is needed were pressure and mole mass is constant, temperature and volume varies. Im stuck putting it all together.

**chemistry**

how do I calculate what temperature is needed to heat 52 grams of ethane to occupy 1200ml?

**physics**

An object is solid throughout. When the object is completely submerged in ethanol alcohol., its apparent weight is 15.2 N. When completely submerged in water, its weight is 13.7 N. What is its volume? Steps please.. answer isnt really necessary

**Physics/Chemistry**

few other questions. 1.) Suppose you expend 430 kilocalories during a long walk, how many liters of ice water at 0 degrees do you need to consume in order to use up the 430 kilocalories of metabolic energy. Stomach can hold 1 liter. 2. A person eats a container of strawberry ...

**Physics**

An object is solid throughout. When the object is completely submerged in ethanol alcohol., its apparent weight is 15.2 N. When completely submerged in water, its weight is 13.7 N. What is its volume? Steps please.. answer isnt really necessary

**Physics/Chemistry**

few other questions. 1.) Suppose you expend 430 kilocalories during a long walk, how many liters of ice water at 0 degrees do you need to consume in order to use up the 430 kilocalories of metabolic energy. Stomach can hold 1 liter. 2. A person eats a container of strawberry ...

**physics**

An object is solid throughout. When the object is completely submerged in ethanol alcohol., its apparent weight is 15.2 N. When completely submerged in water, its weight is 13.7 N. What is its volume? Steps please.. answer isnt really necessary

**C++ Programming**

Where would I find a great video resource for learning Visual C++ for beginners? I'm a newbie and I'm looking in some code for a project on sourceforge that i'm interested in. however, I don't know C++ so i don't know how to contribute to this program. ...

**math**

While on his way to school, Norman saw that the cost of gasoline was $2.50 per gallon. Write a direct variation equation to describe the cost y of x gallons of gas. Then graph.

**Chemistry**

Hi there, I am doing some data calculations for my lab, but I'm having some trouble. Given: Mass of ferrous ammonium sulfate=4.0g Mass of K3[Fe(C204)3] 3H20 =4.53g 1. Using the above mass of ferrous ammonium sulfate, calculate the theoretical yield of the K3[Fe(C204)3] ...

**Quick Question**

yes.

**math**

Writing in math, how can estimating help you add two-digit numbers?

**Chemistry**

Name these compounds (^these are symbolize subscripts) 1. CoCl^3 2. CrF^6 3. AgBr 4. Fe^20^3 5. CrF^3 6. TiCl^4

**Physics help**

A 1.0 kg object is suspended from a vertical spring whose spring constant is 105 N/m. The object is pulled straight down by an additional distance of 0.25 m and released from rest. Find the speed with which the object passes through its original position on the way up.