# Posts by Dan

Total # Posts: 1,211

**Physics**

A sensitive gravimeter at a mountain observatory finds that the free-fall acceleration is 7.0×10−3 less than that at sea level. What is the observatory's altitude?

**Physics**

A 300 ball swings in a vertical circle at the end of a 1.2-m-long string. When the ball is at the bottom of the circle, the tension in the string is 13 . What is the speed of the ball at that point?

**biology**

what can be a represent as a necleus in a room. and WHY

**SraJMcJin**

Hello, I was wondering if you could read my essay and tell me what you think i could do to improve on it. The problem is, I do not want to put it on the internet, so is there a way I can email you my essay?

**algebra**

(4c+2)+(5c) = 92 9c + 2 = 92 9c = 90 c = 10 So there are 10 chairs in each row Alexi set up a total of 42 chairs including the extra 2. Martin set up a total of 50 chairs. 42-(2*4) + 50-(2*5) = ?? 92 - 18 = ???

**English+Essay**

Also whats a good way to end your paragraphs? do i just restate what i wrote?

**English+Essay**

If I start the introductory paragraph to: As a candidate for National Honor Society membership, I believe that I exemplify the high standards expected of its members. Would I need to add on more to it to make it a little bit longer? I was thinking about adding this to it: I ...

**English+Essay**

I have to write an essay, but I have no idea how to start it. It says that my essay has to be MLA formatted, and only 3/4 to 1 page long. 2 page is the longest it can be and must be double placed. Using MLA format, there's is no way for me a write a proper essay with that ...

**math**

There are two machines that produce aluminum cans. The newer machine can produce 7200 cans in 200 minutes. It takes the older machine 300 minutes to produce that many cans. If the two machines work together, how long will it take them to produce 7200 cans? i did 200x+300x = ...

**math**

The length of a rectangle is four times its width. If the perimeter of the rectangle is 50cm. find its area. how do i set this up?

**math**

Justin's gas tank is 1/4 full. After he buys 9 gallons of gas, it is 5/8 full. How many gallons can Justin's tank hold? How would i set that up?

**math**

1. Jina purchased a prepaid phone card for $15. Long distance calls cost 11 cents a minute using this card. Jina used her card only once to make a long distance call. If the remaining credit on her card is $11.04 , how many minutes did her call last? I got 3.96 minutes is that...

**social studies**

a big one. as one might expect whensomeone moves into you bnackyard with tyechnology youve never seen

**AP English**

well, first, God is someone to be afraid of, although loves and thanked too, for pouring his wrath for sinners on His son who died willingly, saving and covereing the sins of anyone who beleives in Him... (this is because Lincoln was a christian..) other than that, its really ...

**math**

ur answer is odd numbers welcome for noing da answer(:!!!!! WELCOME EVERYONE!!!!!

**math**

yay :p thanks

**math**

(4)^2(8) - 12 (16)(8) - 12 128 - 12 = 116 ??

**math**

can you check if answer is right? a^2b -c when a=4 b=8 and c=12

**Math**

typo # 4 answer = -5,9

**Math**

Hello I did my math homework, but I need someone to check if I did it right or not. 1. A = z>=4 B = z<7 Write A or B and A and B using interval notation Answer: A or B = (-infinity, infinity) A and B = [4,7) 2. Write the algebraic expression for the following: 8 is less ...

**physics**

I can't fully understand Fermat's principle of least time (the modern version)

**math**

Identify the conic section whose equation is given: x2 + 10x + y2 + 12y = 60

**math**

what's a point of inflection

**Geometry**

n/a

**chemistry**

I only need help with step 3 We are trying to figure out the charge on Nickel. So we performed titrations. First, 0.6215 g sample of nickle metal was dissovled in 100.0ml of Fe^3+.(acid based) Then, 15.00 ml sample of this solution was taken and titrated. If it took 26.48ml of...

**chemistry**

Heres the simplified version: I need to convert Ni to moles: I have a 0.6215 g sample of Ni that was dissolved in 100.00ml of Fe 3+. Then, 15.00 ml of the sample was taken and titrated. It took 26.48 ml of .0200M Cr2072- to titrate the solution. ] I did the following to find ...

**chemistry**

hi, Im not sure how to explain this well but here goes. Im doing a oxidization/reduction reaction to determine the charge of an element. charge is n formula n=a/b Problem: 0.6215 g sample of nickle metal was dissovled in 100.0ml of fe 3+ Note for the formulas: I put all the ...

**chemistry**

nope not yet

**chemistry**

what are some source errors in my experiment? determine absolute zero. We attached a capillary to a ruler with a thermometer. placed it in water and heated. I recorded and my partner did the readings. source errors: -partner didn't stir the water before he took the ...

**chemistry**

here this might help 4 C3H5(NO3)3(l) → 12 CO2(g) + 10 H2O(g) + 6 N2(g) + O2(g) I must have copied it wrong into the browser. sorry...

**chemistry**

it was given so we don't have to. I think the teacher is just trying to show us how to use the mole ratios to get partial pressures

**chemistry**

the formula is given 4c3h4(no5)3 --->12co2(g) +10h20(g)+6n2(g)+02(g)

**chemistry**

ok heres my question, nitrogylcerin decomposes: 4c3h4(no5)3 --->12co2(g) +10h20(g)+6n2(g)+02(g) whats is the max pressure that a 10.0L container will be able to withstand if 5.00 Nitroglycerin decomposes at temp of 1250c mm of nitroglycerin =227 g/m i got 2.00atm b) what ...

**chemistry**

A mixture of hydrogen peroxide, H2O2, and hydrazine, N2H4, can be used as a rocket propellant. The reaction is: 7 H2O2(g) + N2H4(l) ® 2 HNO3(aq) + 8 H2O(l) a) How many moles of H2O2 react with 0.477 mol N2H4? [1] ___________ b) How many grams of HNO3 can be produced in a ...

**chemistry**

thanks looks like im on track

**chemistry**

question 3: Calculate the density of COCl2, a poisonous gas at 27.0oC and 733 Torr. [3] i got 3.87 g/v

**chemistry**

woops i mesed up here's my answer A .120 b 1.51%

**chemistry**

A 10.0 mL sample of 3.00 M KOH(aq) is transferred to a 250.0 ml volumetric flask and diluted to the mark. It was found that 38.5 ml of this diluted solution was needed to react the stoichimetric point in a titration of 10.0 mL of a phosphoric acid, H3PO4, solution. The ...

**Foundation of Financial Management**

Afirm's cost of financing, in an overall sense, is equal to it's? A: Weighted average cost of capital. B: Required yield that investorrs seek for various kinds of securities. C: Required rate of return that investors seek for various kinds of securities. D: All of the ...

**chemistry**

Does this mean no one is able to or no one has had a chance to answer it?

**chemistry**

I need to balance hydrolysis equations for the following salts,copper(II) nitrate, sodium tetraborate, sodium bromide, calcium sulfite, potassium sulfate,potassium chloride, sodium acetate, and ammonium bromide.

**history**

the answer's b totally

**German**

"My mum has black hair and dark brown eyes. She is very tall. She is very caring but can be quite mean sometimes. Meine Mutti hat schwarze Haare und dunkel braune Augen. Sie ist sehr hoch. Sie ist sehr fürsorglich, aber sie kann manchmal recht bedeuten. My sister is ...

**Math**

The bus fare in a city is $1.75. People who use the bus have the options of purchasing a monthly coupon for $29.00. With the coupon book, the fare is reduced to $0.75. Determine the number of times in a month the bus must be used so that the total monthly cost without the ...

**Math Grade 12**

H=7 -8 cos (2 pi t/3) seems correct, I didn't check your math though. If H is the height of the initial point after t seconds, simply set t = 5.5 seconds and solve for H. H = 7 - 8 cos(2pi*5.5/3)

**Health**

Boyfriends/girlfriends come and go. Abstinence is a one shot deal. Also, someone that is pressuring you to do something you don't want to do probably isn't a good person to be going out with.

**Math**

Assigning each letter of the alphabet the numerical values of its position in the alphabet (a=1, b=2, c=3, etc) find a familiar first name witha product of letter values that is equal to 100,000.

**Chemistry-help**

Fe+S=FeS

**chemistry**

4.20atm

**Physics**

What Net Force is necessary to give a 2.0 kg mass initially at rest an acceleration of 5.0 m/s^2? Is the answer 10. N?

**math**

F=Gm^2/r^2 G=? The answers are: Fr^2/m^2 sqrt(F)m/r sqrt(F)r/m

**math**

E=hf-w w=? The answers are: -E/hf E+hf hf-E

**Math**

E=hf-w w=? My answer was E/hf but I think this is wrong.

**math**

F=Gm^2/r^2 G=? My answer is Fm^2/r^2. Is this right?

**Pre-Cal**

Find f X g 3 sqrt of x+1 X x^3+1

**Spanish**

i sint know man. its up 2 u\

**Math**

use the functions f(x)=x+4 and g(x)=2x-5 to find the specified functions. (g X f)^-1 Would the answer be x+1 over 2?

**Math**

Use the functions f(x)=1/8x-3 and g(x)=x^3 to find the indicated value or function. (g^-1 X f^-1)(-3)

**Math(Please help)**

Use the functions f(x)=1/8x-3 and g(x)=x^3 to find the indicated value or function. (g^-1 X f^-1)(-3)

**Pre-cal**

Compare the graph of the function with the graph of f(x)=|x| y=|-x|

**trig**

how do i get the degree for (tan+1)(tanx-2)=0 in the interval of 0 is less that or equal to x and x is less then or equal to 360

**Pre-Cal**

What is the domain of f/g? f(x)= x over x+1, g(x)=x^3 I have no idea how to figure this out!

**Math**

Find the domain and range of the functon: f(x)=1/2 |x-2|

**Marine Science**

Organisms on a rocky shore compete for all of the following except? 1) Affection 2) Nutrients 3) Space 4) Light I think the answer might be light but im not sure.

**6th grade_Science/Math**

Imagine there is a large boulder on the edge of a shoreline. If a wave period is 15 s long. how many times is the boulder hit in a year? Thank you

**math**

The weights (in pounds) of a sample of five boxes being sent by UPS are: 12, 6, 7, 3, and 10. a. Compute the range. b. Compute the mean deviation. c. Compute the standard deviation.

**Biology**

What cell structure/organelle would be especially common in i)cells lining the respiratory passages? ii)white blood cells that engulf and detroy invading bacteria iii)enzyme (protein) secreting cells of the pancreas

**Physics**

Which would be more effective in breaking a rope: 2 people pulling a rope tug-of-war style, or 2 people pulling the same end of the rope with the other end tied to the wall?

**math**

according to some students what is the true purpose of homework

**spanish**

I need help.. i need to make 4 sentences.. With... (Miro) (Miramos) El, la, al, a la empleado video carpeta profesora I don't care how u make them i just need help..

**Physics**

A 0.250 kilogram box has a speed of 2m/s when it is 1.2 meters from a second mass. It is sliding on a table with a coefficient of friction of 0.20. The box collides and sticks to a 0.5kg box that sits on the end of the table, causing the boxes to fall. How fast are the boxes ...

**Calculus**

Show that y= x + sinx-pi satisfies the initial value problem dy/dx=1 + cos x, y(pi)= 0 i don't understand how to do this problem. i don't know where to begin.

**college**

What is the probability that 4 rolls of fair die will show three 4's? the answer is 0.015, but I don't know how to get it.

**4th grade**

temperature - noun

**probability**

What is the probability that 4 rolls of fair die will show three 4's? the answer is 0.015, but I don't know how to get it.

**probability**

What is the probability that 4 rolls of fair die will show three 4's? the answer is 0.015, but I don't know how to get it.

**Math**

3 choices x 5 choices = 15

**CALC**

find the following derivatives: f(x) = (2x+5)/(x^2-3) f'(x)= (2)*(x^2 -3)-(2x+5)*2x/(x^2-3)^2 is that correct??? f(x)= (lnx)(cos x) f'(x)= 1/x*-sinx or do i have to use the product rule?? thank you.

**calculus**

find the following derivatives: f(x) = (2x+5)/(x^2-3) f'(x)= (2)*(x^2 -3)-(2x+5)*2x/(x^2-3)^2 is that correct??? f(x)= (lnx)(cos x) f'(x)= 1/x*-sinx or do i have to use the product rule?? thank you.

**calc**

t 2 4 6 8 10 12 v(t) 44 42 41 40 37 35 the velocity in the table is decreasing 2 </= x </= 12. Using n=5 subdivisions, approximate the total distance traveled for: a) an upper estimate b) a lower estimate i'm not quite sure what the question is asking. i don't ...

**Calculus**

t 2 4 6 8 10 12 v(t) 44 42 41 40 37 35 the velocity in the table is decreasing 2 </= x </= 12. Using n=5 subdivisions, approximate the total distance traveled for: a) an upper estimate b) a lower estimate i'm not quite sure what the question is asking. i don't ...

**math**

im not 1 of the pros at answering the questions but i think i can help. y=4/9x-7/9. i got this cuz it has to be y=mx+b. when u move the 9y to the other side of the = it becomes negative and the same goes for the 4x. then you have to divide the -4x and the 7 by the -9. the x ...

**Physics**

A spring with spring constant k=100 (N/m) is at its equilibrium length. a) How much elastic potential energy is stored in the spring? b) The same spring is stretched so that it is 6.0 cm longer than its equilibrium length. How much elastic potential energy is stored in the ...

**4thgrade math**

it would be 9 because the number after the point (decimal) is less than 5.

**math**

While shopping for an air conditioner, Adam Bryer consulted the following table giving a machines BTUs and the square footage that it would cool. Ft^2(x) BTUs(y) 150 5000 175 5500 215 6000 250 6500 280 7000 310 7500 350 8000 370 8500 420 9000 450 9500 a. Find the equation for ...

**calculus**

what is the derivative of 1/x??

**calc**

i got -1/x^2 but i don't think that is correct.

**calc**

what is the derivative of 1/x??

**Calc**

When you cough, your windpipe contacts. The speed v, with which air comes depends on the radius,r, of your windpipe. If R is the rest radius of your windpipe, then for r </= R the speed is given by: v=2(R-r)r^2 i got the derivative: v'=4rR-6r what do i do next??

**chemistry**

How do you express the number 6 as two significant figures?

**Chemistry**

If the column of water in the water bormeter rose to a height of 35 feet, what would the atmospheric pressure be in mm Hg?

**Math**

Fluffy, Spot and Champ combined dog years is 91. Spot is 14 years older than Fluffy, Champ is6 years older than Fluffy. Write and equation and solve how old Fluffy is? Thanks

**6th grade**

Thank you. Dan

**6th grade**

The left and right - hand margins on a sheet of paper are both 1.25 inches wide. The total width of the sheet t of paper is 8.5 inches. Write and solve an equation to find the width of the text area that lies betwen the margins.

**chemistry**

84.86

**10th grade Literature**

2. "THEY" are the humans of Earth. The implication is that astronomers on Mars noticed the nuclear destruction of planet earth. This poem was likely written before we knew that there was no intelligent life on mars. It's meant to convey a sense of irony that ...

**Math**

Two different isosceles triangles with perimeter 4a+b? Is this a right angle isosceles triangle?

**American Government**

How did the Founders expect to promote civic virtue in a country as large and diverse as the United States?

**chemistry**

A balloon filled with helium has a volume of 30.0 L at a pressure of 100 kPa and a temperature of 15 degrees C. What will the volume of the balloon be if the temperature is increased to 80 degrees C and the pressure remains constant?

**chemistry**

What is Dalton's law of partial pressures? Explain how this law relates to the fact that mountain climbers must carry tanks of oxygen when scaling high peaks.