# Posts by Devin

Total # Posts: 188

**Chemistry**

Mole Ratio of Mg : Mg3N2 = 3 b: 1 mole of Mg3N2 = moleofmagnesium over 3 = 8.0mol over 3 = 2.67 mol mass of Mg3N2 = mole * molar mass = 2.67 mol * ((3* 24) + (2 * 14)) g / mol = 2.66.67 I hope that helped you out :)

**Chemistry**

Do you have any choices or is it one where you answer it with what you know?

**Gaussian Elimination Method**

Write the system of equations as an augmented matrix. Then solve for x and y. -3x-y=11 -9x-2y=34 Solution =

**Homework**

A poll was taken of 10,439 working adults aged 40-70 to determine their level of education. The participants were classified by sex and by level of education. The results are shown below. Education Level Male Female Total High School or Less 2023 3264 5287 Bachelor's ...

**Conditional Probability**

A certain virus infects one in every 400 people. A test used to detect the virus in a person is positive 90% of the time if the person has the virus and 10% of the time if the person does not have the virus. Let A be the event "the person is infected" and B be the ...

**Math Antics**

A certain disease has an incidence rate of 0.5%. If the false negative rate is 7% and the false positive rate is 2%, compute the probability that a person who tests positive actually has the disease.

**The Value of an Annuity**

What's the answer?

**The Value of an Annuity**

Can you help I don't understand. Thanks

**The Value of an Annuity**

Don't understand?

**Math**

A football is kicked into the air. Its height in meters after t seconds is given by h(t)=-4.9 (t-2.4)^2+29. A. What was the height of the football when it was kicked? B. What is the maximum height of the kick? C. How long did it take for the football to reach its maximum? D. ...

**Education education**

Yep the answer is D.

**science**

Moose and Messi are correct :)

**College Algebra**

The logistic growth function f(t)= 100,000/5000e^-t describes the number of people, f(t), who have become ill with influenza t weeks after its initial outbreak in a particular community. A) How many people became ill with the flu after the epidemic began? B) What is the ...

**Math**

Bank A pays 4.79% compounded monthly, while Bank B pays 4.8% compounded quarterly. Which bank pays more?

**Math**

A store has a $179.99 item on sale for 25% off. What is the discount on this item?

**math**

950

**Math**

County fair tickets can be ordered in advance. There is a one time processing fee of $10 per order. Individual tickets cost $3 a piece for rides and food. Write an algebraic expression to represent the total cost for a visit to the fair.

**ELA**

What effect does Father’s return have on the Sakane family? A Yuki finds it hard to adjust to having both parents tell her what to do B Yuki’s mother continues to worry about the safety of her family C Ken is relieved that his father will take over as head of the ...

**Spanish**

I think its C

**Pre-Calculus**

how do i find the vertical asymptote of x−1 / x(x-2) so far i got x-1 / x^2-2x

**Chemistry**

What is the order of the reaction for the following reaction and for each reagent given? A + 2B + C --> productions Experiment / A / B / C / rate 1 / 0.002 / 0.15 / 0.132 / 0.0057 2 / 0.002 / 0.25 / 0.132 / 0.0158 3 / 0.003 / 0.15 / 0.132 / 0.0114 4 / 0.003 / 0.15 / 0.264...

**math**

Which algebraic expression represents “the difference of 54 and a number”?

**math**

You get one spin.what is the probability of spinning a number larger than 6 out of 8.

**math**

Kim has fraction 1 over 2 cup of almonds. She uses fraction 1 over 8 cup of almonds to make a batch of pancakes

**Hanahan**

Use addition or substitution to find the value of x for this set of equations. 2x - 3y = -15 x = 4y

**Chemistry**

66.9 g of a substance X dissolves in enough water to make 0.428 L of a 0.68 M solution. Calculate the molar mass of X in g/mol.

**Chemistry**

A 0.885 M solution of sulfuric acid (H2SO4) is to be reacted with a 0.552 M solution of sodium hydroxide to make sodium sulfate and water. How many L of the H2SO4 solution will react with 0.842 L of the NaOH solution? Give your answer to 3 decimal places.

**math**

Which quadrilateral has 4 sides of equal length 2 pairs of opposite sides that are parallel and no right angles

**Economics**

what is a hype song to rap to a economics question. Like this example: search (I'm on econ) on youtube

**math**

Ty needs to cut strips of wrapping paper that are each 9 inches wide.If Ty has 2 rolls of wrapping paper that are 15 feet long, how many 9-inch strips can he cut ?

**physics**

43. A block of mass 2.00 kg rests on a ramp tilted at 25.0°. Coefficients of friction for the block/ramp: μs = 0.300, μk = 0.100. A string passing over a high quality pulley connects the block with a bucket as shown below. The bucket contains sand but a hole is ...

**Science**

ranging minerals from the hardest to the softest. Chalk, fingernail. steel screw and paper clip

**Chemistry**

When a chemist burns ammonia according to the reaction below she finds that the reaction releases heat. (It is exothermic.) 4NH3(g) + 3O2(g) 2N2(g) + 6H2O(g) The enthalpy of the reaction DH = -1267 kJ. What is the enthalpy change (in kJ) when 7 grams of ammonia are burned?

**Chemistry**

Calculate the total heat (in Joules) needed to convert 1.602 x 101 grams of ice at -1.383oC to liquid water at 8.554 x 101oC. Melting point at 1 atm 0.0oC Cwater(s) = 2.09 J/goC Cwater(l) = 4.18 J/goC delta Hofus = 6.02 kJ/mol

**physics**

A plane cruising along at 268 m/s, in straight level flight wants to drops a bomb. He is at a height of 1000m. At what distance should the pilot release the bomb in order to hit his target?

**Physics**

(a) How high a hill can a car coast up (engine disengaged) if friction is negligible and its initial speed is 96.0 km/h? (b) If, in actuality, a 750 kg car with an initial speed of 96.0 km/h is observed to coast up a hill to a height 18.0 m above its starting point, how much ...

**8th grade math**

At 2pm the temperature is 22 degrees, by 4am it is negative 7 degrees. We think the answer in the change of temperature is 29 degrees am I right?

**8th grade Math**

Ok, I came up with 29

**8th grade Math**

At 2pm the temperature is 22 degrees, by 4am it is negative 7 degrees. We think the answer in the change of temperature is 22 degrees am I right?

**Urgent--Spanish help! :(**

well i guess she told u!lol

**Algebra**

6-(-5r)=5r-3

**math**

what is the exponential form of 1000 * 1000

**Algebra**

Can anyone please show me how 3^n/6^(2n+1) becomes 1/2^n(6^(n+1))= 1/6)/12^n when you divide top and bottom by 3^n? Thank you and have a great day!

**statistics**

To find out what people think, the Gallup Poll selected a random sample of 520 women and 506 men. The pollsters showed them a list of personal attributes and asked them to indicate whether each attribute was “generally more true of men or of women”. When asked about ...

**College Chemistry**

1 L of N_2_ gas, having a pressure of 2.5 atm, is added 1 L of Ar gas, having a pressure of 3.7 atm, in a sealed, rigid flask. What is the final pressure in the flask?

**Science**

Dexter is correct

**math**

How do you solve sqrt(1-(9/x^2))? I know the answer is sqrt x^2 -9/x but I'm not sure how to get the answer on my own. If you could show steps on how to get the answer that would help me a lot!

**SCIENCE 1 QUESTION PLS HELP ASAP**

C is the answer:)

**math**

how do I figure the circumference of race track that takes 3 lap to make a mile?

**math**

78

**science**

The answer is 14 days I took the quiz.

**Science**

THIS SHII IS LAME

**math**

Jeff Iron $250 on his $5000 certificate of deposit last year. what simple interest rate did the bank pay him?

**chemistry**

A 7.56-g sample of gas is in a balloon that has a volume of 10.5 L. Under an external pressure of 1.05 atm, the balloon expands to a volume of 15.00 L. Then the gas is heated from 0.00 degree C to 25 C. If the specific heat of the gas is 0.909 J/g*C, what are work, heat, and ...

**Chemistry**

ph=10.3

**Complex Physics Problem**

A ladder can fall for two reasons. If it is set too steep and climber gets their mass to the left of the ladder's base, the ladder likely will fall over backwards. If the ladder is set at too shallow of an angle the required force of friction between the ladder and the ...

**College Level Physics**

A horse pulls a cart with a force of 145 newtons at an angle of 30 degrees above the horizontal and moves along at a speed of 2.5 m/s. How much work to the nearest kJ does the force do in 6 minutes?

**Physics 1 College Level**

A planet/moon has a mass of 77.89 × 1023 kg and a radius of 7.9 × 106 meters. What is g on the surface to the nearest hundredth of a m/s2? Once again, not really sure where to go with this. Out of the 10 problems I've only had trouble with this and one other.

**Physics 1 College Level**

Spaceship is 2.5 x 10^7 kg! Asteroid is 3.5 x 10^18 kg. Thanks! I'll try and figure it out and compare answers if you respond back!

**Physics 1 College Level**

If D = 3204 meters and d = 1247 meters in the figure, what is the magnitude of the force on the space ship to the nearest MN? Consider all three to be point masses. I'm not even sure to begin with this question. Any help will be much appreciated!

**Math**

A state lottery requires you to choose 4 cards from an ordinary deck: I heart, 1 club, 1 diamond, and 1 spade in that order from the 13 cards in each suit. If all four choices are selected by the lottery, yo win $5,000. It costs $1 to play. Find the expected payback.

**university**

n^2+n+1 = (n+1)^2 - n (n+1)^2 and n will always have the different parity, so the difference between them is always odd.

**probability**

6 male students and 3 female students sit around a round table. What is the probability that no 2 female students sit beside each other?

**MATH**

110% OF $8.50

**Calculus**

The area bounded by the curve y = 2x^2-x^3 and line y=0 is rotated around the y-axis. The volume of the resulting structure can be expressed as V = a(pi)/b, where a and b are coprime positive integers. What is the value of a + b?

**GEOmetry**

4455551 = 4x4x5x5x5x5x1=10000 the proof is not valid.

**Pre-calculus; urgent ! Please help !**

I'm taking this same class you should add me on Facebook lol Symone kaepernick

**math**

If Mark invests $8000 at 6% simple interest rate, how much money must he invest at an 8% simple interest rate in order for the interest on each investment to be $500. Assume that the amount of time for both investments is the same.

**Math**

The velocity of a body A is given by v(t) = 2t^i + t 3^j. The body starts from rest at time t = 0 and position s(0) = 2^i 10^j. At what time, t, does the body cross the X axis? What is the average velocity of the body for the time interval, t = 0 and the time that it crosses ...

**Dynamics**

The acceleration of a particle moving along a straight line is inversely proportional to its speed with the constant of porpotionality being k. The body starts from the position s = x0 ^i with initial speed v0. Determine the velocity of the particle as a function of time t. ...

**Arbor**

19

**Algebra2**

Find and simplify a) f(a), b) f(a + h) and c) F(a+h) - f(a) / h ; 1. f(x) = x^2 + 5x -10

**Calculus**

Can I simplify (x^.75)((200-3x)^.5)?

**calculus**

1/4x+(6)3/4

**Physics**

A bullet with a mass m=12.5 g and speed v=85.4 m/s is fired into a wooden block with M=113 g which is initially at rest on a horizontal surface. The bullet is embedded into the block. The block-bullet combination slides across the surface for a distance d before stopping due ...

**Successive approximations**

Find all root of ln(4-x^2)=x correct to 8 decimal places. List all successive approximations.

**Calculus**

Graph the following function. Find and state the domain, intercepts, asymptotes, intervals of increase and decrease, local extrema, concavity, and inflections points. F(x)=(x+1)/(square root(x^2+1)) I got so far... Domain: (-infinity, infinity) Intercepts: (0,1)and(-1,0) ...

**Physics**

A baseball is hit at ground level. The ball reaches its maximum height above ground level 3.2 s after being hit. Then 2.7 s after reaching its maximum height, the ball barely clears a fence that is 81.0 m from where it was hit. Assume the ground is level. (a) What maximum ...

**Physics**

A baseball is hit at ground level. The ball reaches its maximum height above ground level 3.2 s after being hit. Then 2.7 s after reaching its maximum height, the ball barely clears a fence that is 81.0 m from where it was hit. Assume the ground is level. (a) What maximum ...

**Physics**

A train at a constant 44.0 km/h moves east for 42 min, then in a direction 45.0° east of due north for 17.0 min, and then west for 51.0 min. What are the (a) magnitude (in km/h) and (b) angle (relative to north, with east of north positive and west of north negative) of ...

**Physics**

A batter hits a pitched ball when the center of the ball is 1.35 m above the ground.The ball leaves the bat at an angle of 45° with the ground. With that launch, the ball should have a horizontal range (returning to the launch level) of 106 m. (a) Does the ball clear a 8....

**Physics**

A baseball is hit at ground level. The ball reaches its maximum height above ground level 3.2 s after being hit. Then 2.7 s after reaching its maximum height, the ball barely clears a fence that is 81.0 m from where it was hit. Assume the ground is level. (a) What maximum ...

**practical english**

Which of the following sentences contains an italicized word that's used as a predicate adjective? A. Jerry looks ILL today. B. Jerry looks INTO the microscope. C. Jerry looks disdainfully at the pile of laundry D. Jerry looks at the map. Is it c?

**health**

is it d

**Physics**

How do I find Vector Resolution F = 0.300 g N, theta = 60 degrees. Do I take tan inverse (.3 sin 60/.3 cos 60)?

**College Finite**

Assume that the student has a cup with 13 writing implements: 7 pencils, 4 ball point pens, and 2 felt-tip pens. In how many ways can the selection be made if no more than one ball point pen is selected?

**chemistry**

What is the density of a substance that weighs 500g and fills a container that is 1/2 liter in size?

**college algebra**

an executive invests $29,000 some at 7% and some at 6% annual interest. if he receives an annual return of $1870, how much is invested at each rate?

**College Physics**

A person jumps from a window 34 meters high and is caught in a firefighter's net which stretches 0.6 meter. To the nearest m/s^2, what is the magnitude of the person's acceleration in the net?

**Geometry**

Company "A" sells soil at 11 cents per cubic foot. While company "B" sells it at 3 dollars per cubic yard. You need to have 20 cubic yards of soil planted. What is the better company to go with? and how much will you save?

**American History**

is it D

**Enlish III**

The graduation cermoney lasted only two hours. What part of the sentence is lasted only two hours? A) verb B) compound verb C) complete Predicate D) Complete subject

**chemistry**

A gas has a volume of 50.0 cm3 at a temperature of -73°C. What volume would the gas occupy at a temperature of -123°C if the pressure stays constant?

**Calculus**

a.) Given that f(3)=5 and f'(x)=x/((x^3)+3), find the linear approximation of f(x) at x=3. b.)If the linear approximation is used to estimate the value of f(2.9), will it be an overestimation or underestimation? Show justification

**Math**

a.) Given that f(3)=5 and f'(x)=x/((x^3)+3), find the linear approximation of f(x) at x=3. b.)If the linear approximation is used to estimate the value of f(2.9), will it be an overestimation or underestimation? Show justification.

**Math**

The stopping distance d of a car in feet is related to the speed in mph by the equation d(s)=.02s^2+1.1s Calculate the speed when your stopping distance is: 1.) 51ft 2.) 315.12ft

**Math**

A math teacher wrote x^2+bx+c=0 on the board and asked students to find the two real roots. Alice miscopied one of the coefficients and found that 1 and 4 were the roots. Andy miscopied a different coefficient and found that -2 and 3 were the roots. Determine the roots to the ...

**Math**

Find the roots of the given equation by completing the square: ax^2+bx+c=0

**algebra**

The time it takes you to go 12 miles upstream is 5/4 the time it takes you to go 14 miles downstream. If the current is 3mph, how fast do you go in still water.