Friday

October 21, 2016
Total # Posts: 2,374

**chemistry**

what is the mass of sodium nitrate (85.00g/mol) that releases 2.55L of gas at STP?

*April 5, 2013*

**Math**

I think the answer is 3/4

*April 2, 2013*

**Chemistry**

Okay, I calculated that it should be Fe^2+ that precipitates out first and the concentration of CO3^2- is 9.55x10^-10. is that correct? in regards to question b: where is K2CO3 coming from? how am I using that in the calculation?

*April 1, 2013*

**Chemistry**

I am so overwhelmed. can somebody please help me? Consider a solution that is 0.022 M in Fe^2+ and 0.014 in Mg^2+ A) if K2CO3 is to selectively precipitate one of the cations while leaving the other cation in solution, which cation will precipitate first? B) What minimum ...

*April 1, 2013*

**math **

howard has 3 m of ribbon. how many centimeters is that

*March 30, 2013*

**math**

two third of a blueberry pie is left in the refrigerator. If the leftover pie is cut in 6 equal size, which fraction of the original pie is each slice

*March 20, 2013*

**Life orientation**

Ways in which the human or enviromental problem impacts have on the community

*March 18, 2013*

**math**

i actually need the anwser my self

*March 15, 2013*

**Algebra **

you trim a large square picture so that you could fit it into a frame. you trim 3 inches from the length and 2 inches from the width. the area of the resulting picture is 56sq in what was the perimeter of the original large square picture?

*March 12, 2013*

**Chemistry**

What is the mass of gas dissolved in a solution at 150kPa if 0.35g of the gas dissolves in 2.0L of water at 30kPa?

*March 3, 2013*

**math**

rectangular prism with a volume of 72 cubic inches; sum of the 3 lengths is 13; width is half of the height; the length is one more than the width what are the dimensions of the rectangular prism

*February 27, 2013*

**math fractions**

i don't know

*February 26, 2013*

**Finance**

After visiting several automobile dealerships, Richard selects the car he wants. He likes its $18,500 price, but financing through the dealer is no bargain. He has $3,700 cash for a down payment, so he needs an $14,800 loan. In shopping at several banks for an installment loan...

*February 15, 2013*

**Finance**

Joshua borrowed $2,300 for one year and paid $138 in interest. The bank charged him an $15 service charge. If Joshua paid the $2,300 in 12 equal monthly payments, what is the APR? (Round your answer to 1 decimal place

*February 15, 2013*

**Chemistry (Stoichiometry)**

Heres a balanced equation: Na2CO3(aq)+2AgNO3 (aq) --> 2NaNO3(aq)+Ag2CO3 (s) From this equation, 10 mL of AgNO3 in this contains 34 grams of AgNO3. Calculate the grams of solid product, Ag2CO3. Part 2: 10 mL of Na2CO3 in this experiment contains 21 grams of Na2CO3. ...

*February 6, 2013*

**Logarithms**

help- e^1-5x=3 find solution to 4 decimal places. I don't know how to type it in to my calculator!

*February 5, 2013*

**vocabulary**

It won’t take long to clean, but you can’t do it. Your clothes are on the floor, and games are everywhere.

*February 5, 2013*

**physics**

use x = x0 + v0*t + 1/2*a*t^2 v = v0 + a*t where x is position, x0 is initial position, v0 is initial speed, a is acceleration/deceleration, t is time, and v is speed as a function of time a) 56 - 6.2*t^2 = 0 Solve for t, the time it takes for the speed to go to zero. The ...

*February 4, 2013*

**algebra**

aletha earns $6.40 per hour

*January 31, 2013*

**physics**

After one second, when the patrol car is at location x = 0, the student is at 45 m. The student's location as a function of time, where t=0 when the police car starts accelerating is 45 + 45*t The policeman's position is 1/2*3*t^2 Set these two equations equal to each ...

*January 30, 2013*

**Physics**

Force = mass*acceleration Since the book is at rest in your hands and not moving, the net force is 0.

*January 30, 2013*

**physics**

First, find the x and y components of all vectors: Ax = -6.2*cos(52) Ay = 6.2*sin(52) Bx = 6.6*cos(27) By = 6.6*sin(27) Cx = 2.8*cos(57) Cy = -2.8*sin(57) Dx = Ax - Bx + 3*Cx Dy = Ay - By + 3*Cy D has a magnitude of D = (Dx^2 + Dy^2)^0.5 and a direction of theta given by tan(...

*January 30, 2013*

**Physics**

v(air) = lambda*fair where lambda is the wavelength, fair is the frequency in air v(helium) = lambda*fhelium v(air)/v(helium) = f(air)/f(helium) Look up the speed of sound in air and solve for f(helium)

*January 30, 2013*

**Physics**

the fourth standing wave frequency is 4*f1, where f1 is the fundamental wave frequency. The seventy fundamental frequency is 7*f1 7*f1 - 4*f1 = 3*f1 = 144 hz f1 = 144/3

*January 30, 2013*

**Physics**

(2.5 cm)sin[(3.0 m-1)x - (27 s-1 )t] + (2.5 cm)sin[(3.0 m-1)x + (27 s-1)t] = (5cm)sin[(3.0m-1)x - (27 s-1)t]

*January 30, 2013*

**Math**

A) 12 choose 3, calculated as 12! / (3! * 9!) = 12*11*10 / (3*2)

*January 30, 2013*

**Physics**

Energy = Power*time Power = I^2*r = I*V = 1.5*1.2 5 * 10^3 = 1.5*1.2*time solve for time. Your answer will be in the SI units of seconds; divide this answer by 60 sec/min to convert the answer to minutes

*January 29, 2013*

**computer science**

You're going to have to look up the functions in the particular language you're working with to learn how to store arrays, select elements of the array, and print statements.

*January 29, 2013*

**Chemistry**

Calcium propanoate or calcium propionate has the formula Ca(C2H5COO)2 . . . try using your textbook to look up the chemical formulas for the other reactants involved in these equations. . . such as hydrogen chloride and anhydrous ethanoic acid. Then research how these ...

*January 29, 2013*

**maths**

I imagine you're supposed to solve for the missing variables. I'll do a couple so you get the idea. 1) 2a - a/5 = 2/3 adding like terms: 1.8 a = 2/3 9/5 a = 2/3 a = 10/27 2) 3(a+4)+1 = a/2 3*a + 12 + 1 = a/2 3*a + 13 = a/2 13 = -2.5a a = 13/-2.5 . . .

*January 29, 2013*

**Algebra 1- Math**

2x - y = -4 -3x + y = -9 From the first equation: y = 2x + 4 Substitute this into the second equation: -3x + 2x + 4 = -9 -x + 4 = -9 -x = -13 x = 13 Then plug this answer back into the first equation 2*13 - y = -4 26 - y = -4 -y = -30 y = 30

*January 29, 2013*

**Chemistry**

You need to calculate the equilibrium constant K, which for C would be ([H2BO3-]*[CO3 2-]) / ([HCO3-]*[HBO3 2-]) Look up the equilibrium concentrations [] of the various compounds, and solve. If K > 1, products are favored. If K is less than 1, than reactants are favored

*January 29, 2013*

**help**

First, plot the parallelogram on graphing paper. Next, calculate the length of each side using the formula for the distance between 2 points (x1, y1), (x2, y2): ((x1-x2)^2 + (y1-y2)^2)^0.5 Then calculate the slope of each line passing through these two points: slope = (y2-y1...

*January 29, 2013*

**geometry**

why don't you try getting out your compass, following each of the student's steps, and see which one yields a parallelogram PQRS?

*January 29, 2013*

**Math**

Let P be the principal invested. The amount at the end of four years will be for each scenario 1: P*(1+0.0225/2)^(4*2) 2: P*(1+0.0225/4)^(4*4) 3: P*(1.0195^4)

*January 29, 2013*

**statistics**

I. 71. The mode, by definition is the answer that appears most frequently. II. The midrange is 64, which is by definition the arithmetic mean of the largest and the smallest values in a sample or other group. The range is 55. Let H = highest score, and L = lowest score. Then...

*January 27, 2013*

**probability**

suppose that the times taken to complete an online test are normally distributed with a mean of 45 minutes and a standard deviation of 12 minutes. find the probability a. that for a randomly selected test, the time taken was more than 1 hour. b. that the mean number of minutes...

*January 21, 2013*

**science**

250 mL

*January 20, 2013*

**Physics**

The length of the telescope is 0.2 + 1.6

*January 20, 2013*

**concepts to population health**

They should use this data to identify where resources should be most efficiently concentrated/directed in order to best affect the health outcomes of the population as a whole.

*January 20, 2013*

**Physics**

y = y0 + vy0*t -1/2*g*t^2 x = x0 + vx0*t where y is the y position as a function of time, y0 is the initial y position, vy0 is the initial y velocity, g is the acceleration due to gravity (9.8 m/s^2), t is time, x is the x position as a function of time, vx0 is the initial x ...

*January 20, 2013*

**Math**

You can take any two currency exchange rates and divide them by each other to get 1: for example 1 CDN = $0.829 Dividing both sides by 1 CDN 1 CDN / 1 CDN = 1 = $0.829/1 CDN Since you can multiply anything by 1 and still get the same result (1*x = x); You can multiply by the ...

*January 20, 2013*

**Math**

What is the smallest of 3 consecutive positive integers if the product of the smaller two integers is 5 less than 5 times the largest integer? I can't remember how to start this.

*January 15, 2013*

**Math**

What is the smallest of 3 consecutive positive integers if the product of the smaller two integers is 5 less than 5 times the largest integer? I can't remember how to start this.

*January 15, 2013*

**Precalculus/Trig 5**

sin(26) = (120+15)/guywire where guy wire is the length of the guy wire

*January 14, 2013*

**statistics**

make a plot rounding to the nearest ten: (1, 630); (2, 670); (3, 740); (4,650); . . . then a plot rounding to the nearest 100: (1, 600); (2, 700); (3, 700); (4, 700) . . . c. What is the average El Nino rain (628 + 669 + 740 + . . . + 872) / 23 Is this less or greater than the...

*January 14, 2013*

**muniz**

Q = m*c*(130- -22) where m is the mass of the water, c is the specific heat of water, which you will have to look up; Make sure it matches with your units of mass and temperature

*January 14, 2013*

**economics**

If she had worked those two days, she would make +$200 Instead, she spends $180 + $198 = $378 The total opportunity cost is 378 + 200 = 578. This is how much money she'll lose by going on the trip instead of working

*January 13, 2013*

**physics**

centripetal acceleration is v^2/r The tension in the chain is m*v^2/r where v is the speed = 2*PI*r*f where f is the frequency; r is the radius; m is the mass v = 2*PI*1.2*0.432 solve for the acceleration and tension using the above equations

*January 13, 2013*

**Physics**

v = 2*PI*r/T where T is the period 2010 = 2*PI*0.15/T centripetal acceleration = v^2/r Force = m*v^2/r

*January 13, 2013*

**math**

The greatest coin is a quarter; If you choose three quarters, you only have $0.75, so $5.00 is greater.

*January 13, 2013*

**Physics**

Take components of the force: F1x = 364*cos(33) F1y = 364*sin(33) F2x = 522*cos(11) F2y = 522*sin(11) Fnetx = F1x + F2x Fnety = F1y + F2y Fnet = ((Fnetx)^2 + (Fnety)^2)^0.5 at an angle theta given by tan(theta) = Fnety/Fnetx where Fnet = m*a = 3050*a Solve for a, the acceleration

*January 13, 2013*

**Chemistry**

lamda * f = c where c is the speed of light = 3*10^8 m/s; f is the frequency; lambda is the wavelength.

*January 13, 2013*

**Machanics**

vf - vi = 5*10^6 - 2*10^6 = 3*10^6 where vf is the final speed and vi is the initial speed. Assuming a constant deceleration, the electron passes through 2.1 multiply 4cm = 8.4 cm of paper. 8.4 = 1/2*a*t^2 deltav = 3*10^6 = a*t where a is the acceleration, t is the time. You ...

*January 13, 2013*

**Physics**

525 - 413

*January 13, 2013*

**Physics**

You are not going to die. You just might not get the right answer.

*January 13, 2013*

**physics**

Use conservation of momentum. In the x direction: 0.02*5.5 = 0.02*vA*cos(65) + 0.04*vB*cos(37) In the y direction: 0 = 0.02*vA*sin(65) - 0.02*vB*sin(37) You should be able to use algebra to solve for these equations, since you have two equations with 2 unknowns; vA is the ...

*January 13, 2013*

**physics**

F(q2) = ke*q1*q2/(r12)^2 + ke*q3*q2/(r23)^2 = 0 or q1*q2/(r12)^2 = q3*q2/(r23)^2 q*-2q/(r12)^2 = 3q*-2q/(r23)^2 -2*q^2/(r12)^2 = -6q^2/(r23)^2 or 1/(r12)^2 = 3/(r23)^2 where r12 is the distance between charge 1 and 2; r23 is the distance bewteen charge 2 and 3. For symmetry ...

*January 13, 2013*

**Physics**

deltaL = a*L*deltaT where deltaL is the change in length, a s the linear expansion coefficient, L0 is it's initial length, deltaT is the final temperature deltaL = 10^-5*178*(-35 - 39)

*January 9, 2013*

**math**

N = (1 + E)^12 -1 where N is the nominal interest rate per year; and E is the effective monthly interest rate per year. For Ally Bank, (N+1)^10 = 1.25 Use this equation to solve for N: N+1 = log10(1.25) N = log10(1.25) - 1 Then use the first equation to find E

*January 8, 2013*

**math (calculate speed)**

m*g*h = 1/2*m*v^2 where m is the mass; g is the acceleration due to gravity; v is the speed. At the top of his dive, the swimmers energy is entirely potential energy = m*g*h; When he enters the pool, the potential energy is converted to kinetic energy: 1/2*m*v^2 v = = (2*g*h)^0.5

*January 8, 2013*

**Math**

-3*y + 2*x = -12 multiply both sides by a negative 1: 3*y - 2*x = 12 3*y = 12 + 2*x y = 2/3x + 4 This is an equation of a line with slope 2/3; y intercept = 4; Graph this equation; the graph of this line is the solution to this equation

*January 8, 2013*

**Physics, waves**

v = (T/mu)^0.5 where v is the speed, T is the tension, and mu is the linear density v = lamda*f ; lambda = 2*L for the fundamental mode, where f is the frequency, and lambda is the wavelength f = (1/(2*L))*(T/mu)^0.5 1.61 g = 0.00161 kg mu = 0.00161/0.64 200 = (1/(2*0.64))*(T/...

*January 8, 2013*

**science, physics**

The total energy is entirely kinetic energy as the block passes through the equilibrium position E = 1/2*m*v^2 where m is the mass, and v is the velocity

*January 8, 2013*

**Physics**

9.4 cm = 0.094 m x = -0.094*cos(w*t) v = dx/dt = 0.094*sin(w*t) where w = (k/m)^0.5 x is the x position; v is the speed; w is the angular velocity; k is the spring constant; m is the mass at t = 0.24 s, v = 0.094*sin(((2080/0.46)^0.5)*0.24)

*January 8, 2013*

**math**

Her expectation of winning is 1%. The fair value is $200/100 = $2.00

*January 8, 2013*

**maths**

Let the rate at which A works be a; the rate at which B works be b; the rate at which C work be c: (a + b)*12 = 1 (b + c)*15 = 1 a = 2*c gives b + a/2 = 1/15 b = 1/15 - a/2 Substituting into the first equation: (a + 1/15 - a/2)*12 = 1 a/2 + 1/15 = 1/12 a/2 = 1/12 - 1/15 = (15-...

*January 8, 2013*

**algebra**

Plot the points (140, 1.4); (150, 1.25); (170, 0.93); (175, 0.78); (205, 0.43) on your graphing calculator; Use your calculator manual to find out how to fit this data to a straight line (linear model), and then a quadratic equation (quadratic model) Look at the results; which...

*January 8, 2013*

**Physics**

The velocity of the passenger is (50-3) = 47 m/s East

*January 7, 2013*

**Social Studies**

Summarize the major factors that allowed the Incas to conquer and rule their large empire. Some suggest that, in many ways, the Incas were like the Romans or other Pre-Columbian American Civilizations. Evaluate whether they were more similar or different, and why. Make sure to...

*January 6, 2013*

**calculus**

solve the following logarithmic equation. Be sure to reject any value of x that is not in the domain of orginal expression. then in the solution set round to two decimals places. Inx=8 I get e^8 But am having a hard time with rounding two decimal places. Can someone help?

*January 1, 2013*

**calculus**

Thanks for telling me how to actually write it here.

*December 31, 2012*

**calculus**

solve the following exponential equation. exact answers only 1-8x 3x ¨i =e *I know that I did not post this correctly but I do not know how to put the 1-8x above the pie symbol and 3x above the e.

*December 31, 2012*

**calculus-can someone please help me with this ques**

I have two questions if someone can PLEASE help. 1.solve the equation in the real number system. x^4+11x^3+24x^2-23x+35=0 **Please show work** 2.Use the remainder theorem to find the remainder. When f(x)is divided by x-3. Then use the factor theorem to determine whether x-3 is...

*December 30, 2012*

**math**

Using the best-fit line below for prediction, answer the following questions: a) What would you predict the price of Product X in volume of 150 to be (approximately)? b) What would you predict the price of Product X in volume of 100 to be (approximately)?

*December 29, 2012*

**Physics **

What is the frictional force between the tires of a 2000 kg car and an asphalt road if the coefficient of friction is 1.2?

*December 20, 2012*

**Physics**

If the coefficient of kinetic friction between a 36 kg crate and the floor is 0.31, what horizontal force is required to move the crate at a constant velocity (so that FNET=0.0 N) across the floor?

*December 20, 2012*

**Physics **

What is the frictional force between the tires of a 2000 kg car and an asphalt road if the coefficient of friction is 1.2?

*December 20, 2012*

**Physics**

Look up the density of saltwater and the density of fresh water. The ship will sit higher in the liquid with greater density. The density of the water displaced times the volume of the water displaced is equal to the weight of the ship. A fluid with a greater density will ...

*December 18, 2012*

**maths**

Let the new point be (x1, y1, z1) Then, using the distance formula: ((x1-1)^2 + (y1-3)^2 + (z1-3)^2)^0.5 = 5 (x1-1)^2 + (y1-3)^2 + (z1-3)^2 = 25 Put all units in terms of one variable. I'm choosing x1 first: x1+2/3 = y1+1/2; y1 = x1 + 2/3 - 1/2 = x1 + 1/6 x1 + 2/3 = z1-3/2...

*December 18, 2012*

**math**

For the square with area 25 yd^2, x^2 = 25; x = 5; where x is the length of a side of the square. The perimeter of this square is 5*4 = 20 For the square with area 5 yd^2, y^2 = 5; y = 5^0.5; where y is the length of the side of this square. The perimeter of this square is 4*(...

*December 18, 2012*

**chemistry**

pH = -log[H+] pOH = -log[OH-] and pH = pOH = 14 pOH = -log(0.01) = 2 2 + pH = 14; pH = 12

*December 18, 2012*

**C++**

This is a perfect opportunity for you to develop the skill of reading your textbook and finding the necessary information. You will probably need to find functions that read and search data, separate data into components, and store data. Find these functions, and read through ...

*December 18, 2012*

**science**

Available is a 5 M/liter solution. You need 100 mL of a 0.91 M solution. In units of moles, you need 0.91 mol/liter * 0.1 liter = 0.091 moles of HNO3 0.091 moles / (5moles/liter) = 0.0182 liters of the 5 M solution. Take 0.0182 liters of the 5 M solution, and dilute to 100 mL...

*December 17, 2012*

**Calculus**

V = 4/3*PI*r^3 dV/dt = 12 = 4*PI*r^2*dr/dt = 4*PI*1^2*dr/dt Solve for dr/dt, the rate at which the radius is growing

*December 17, 2012*

**help math**

vboat + vcurrent = 23/3.6 vboat - vcurrent = 23/3 where vboat is the speed of the boat without a current, v is the speed of the current. The first equation models the boat traveling with the current; the second equation models the boat traveling against the current. Use ...

*December 17, 2012*

**Algebra 2**

graph the function on your graphing calculator. The domain is the set of x values for which the function is defined; the range is the set of y values. Look at the graph and determine the set.

*December 17, 2012*

**physics**

deltaQ = 0; where Q = m*C*T m is the mass, C is the specific heat, T is the temperature 608*C*(Tf-77) + 429*C*(Tf-23) = 0 Where Tf is the final temperature Solve for Tf

*December 17, 2012*

**Calculus**

The boundaries for phi are 0 to 2*PI The boundaries for theta are 0 to PI

*December 16, 2012*

**physics**

Q = m*C*(Tf-Ti) where Q is the heat, m is the mass of the substance, C is the specific heat, Tf is the final temperature; Ti is the initial temperature. deltaQ = 0 or 5*C(Tf - 10) + 1*C*(Tf - 40) = 0 divide by C: 5*(Tf-10) + (Tf-40) = 0 Solve for Tf.

*December 16, 2012*

**statistics**

a) 160 males answered the survey; and 110/160 = 68.75% preferred the current schedule. 140 females answered the survey, and only 50/140 = 35.71% preferred the current schedule, and 90/140 preferred the flex schedule b) One way of describing the preferences is that males are ...

*December 16, 2012*

**physics**

angular momentum of a hoop is m*r^2; the angular momentum of a solid cylinder is 1/2*m*r^2; the angular momentum of a solid sphere is 2/5*m*r^2; the Angular momentum of a hollow spherical shell is 2/3*m*r^2

*December 15, 2012*

**physics**

Volume of air in the balloon = V =(4/3)*PI*r^3 = (4/3)*PI*0.5^3 mass of air displaced is 1.29 * V mass of helium is 0.181*V Upward force due to pressure difference between helium and air is (1.29 - 0.181)*V Sum of forces in the y direction is 0: (1.29 - 0.181)*V - T - 0.0120...

*December 15, 2012*

**Physics**

F = -k*x where F = force, x is displacement 70.4 = -k*0.0535

*December 14, 2012*

**physics**

F*x = 1/2*m*v^2 where F is the average force, x is the distance over which the bullet is accelerated, v is the speed, m is the mass of the bullet F*0.432 = 1/2*22*907^2

*December 14, 2012*

**Physics**

Power = F*v where F is the force, v is the speed 53.3 = F * (1.32m/1.22s)

*December 14, 2012*

**Math**

Evaluate each of these answers: For example, evaluate A. (-1/2)^4 + 7*(1/2)^2 - 9*(1/2) -1 and 0^4 + 7*0^2 - 9*0 -1 If one of these answers is negative and one of these is positive, then the Intermediate Value Theorem guarantees taht the polynomial has a root in this interval...

*December 14, 2012*

**Algebra 1- Math**

a. At the start, months = 0; employees = 2. In 6 months, months = 6; employees =14 (0,2) (6,14) b and c. 2 employees/month is the slope This is how many employees the company would have to add per month to get 14 employees at the end of 6 months E = 2 + r*m where E is the ...

*December 14, 2012*

**Chemistry**

MnO4−(aq) + SO32−(aq) + H+(aq) → Mn2+(aq) + SO42−(aq) + H2O(l) in the form a*MnO4−(aq) + b*SO32−(aq) + c*H+(aq) → d*Mn2+(aq) + e*SO42−(aq) + f*H2O(l) Start by counting how many of each are on each side. I'm going to choose to...

*December 14, 2012*