Monday

April 21, 2014

April 21, 2014

Total # Posts: 1,940

**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

**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]

**Math**

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

**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

**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.

**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 compound...

**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 . . .

**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

**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

**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)/...

**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?

**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)

**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,...

**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...

**science**

250 mL

**Physics**

The length of the telescope is 0.2 + 1.6

**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.

**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 v...

**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 c...

**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 c...

**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.

**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.

**Precalculus/Trig 5**

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

**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...

**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

**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

**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

**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

**math**

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

**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

**Chemistry**

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

**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 h...

**Physics**

525 - 413

**Physics**

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

**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 fina...

**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 sa...

**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 sa...

**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)

**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

**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

**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

**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/...

**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

**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)

**math**

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

**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-...

**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...

**Physics**

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

**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...

**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?

**calculus**

Thanks for telling me how to actually write it here.

**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.

**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...

**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)?

**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?

**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?

**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?

**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 requ...

**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...

**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*(...

**chemistry**

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

**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 ...

**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...

**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

**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 algebr...

**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.

**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

**Calculus**

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

**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.

**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 al...

**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

**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 =...

**Physics**

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

**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

**Physics**

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

**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....

**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 numb...

**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...

**Algebra 2**

B = P*e^(Yr) where B is balance, P is principle = 1600; e is the number e; Y is the number of years; and r is the rate 0.079 Plug these numbers in and solve for the answer.

**physics**

Start the person at (0,0), and calculate the new position after each path. After path 1: (80,0) After path 2: (80, -250) After path 3: x displacement is -130*cos30; y displacement is -130*sin30 (80 - 130*cos30, -250 -130*sin30) After path 4: x displacement is -190*cos30, y dis...

**Science**

Yes

**math**

How many squares are on each side? x*y = 49 where x the number of squares for the width, and y is the number of squares for the length. 120000 = X*Y where X is the width in feet, Y is the length in feet 120000/49 = (X/x) * (Y/y) You have X/x = Y/y

**Math help give example**

Third degree means that it has one term to the power of three. One example: x^3 + x^2 + x + 1

**business**

Look up how the vehicle should be serviced -- i.e., checkup every 5000 miles? etc. Determine the best method of doing so--consider all options available, such as hiring one person to do the job, scheduling periodic checkups at a repair shop, etc.

**Math help storie problem**

let g be the price of green peppers and r be the price of red peppers. 3*g + 2*r = 3.45 4*g + 3*r = 5.00 Use algebra to solve for g and r

**calculus**

The derivative of sinh(x) is cosh(x), and the derivative of cosh(x) is sinh(x) So the nth derivative of sinh(x) is cosh(x) if n is odd; and the nth derivative of sinh(x) is sin(x) if n is even The nth derivative of cosh(x) is sinh(x) if n is odd; and the nth derivative of cosh...

**Physics**

rho1*V1 = rho2*V2 where rho1 is the density of the object; V1 is the volume of the ship; rho2 is the density of the water; V2 is the volume of the water mass of object = 0.97 106/g = 0.97 106/9.8 density of object = 0.97 106/(9.8*0.03*A) where A is the area (0.97 106/(9.8*0.03...

**geometry**

Determine the approximate midpoint of all the areas serviced, both in terms of distance, and with respect to traffic speed limits, road conditions, etc.

**College Algebra**

x*y = 480 2x + 2y = 88 solve for x and y, the width and length

**Physics**

v = v0 - 1/2*g*t^2 where v is speed as a function of time, v0 is the inital speed, and g is the acceleration due to gravity v = 24 - 4.9*t^2 = 0 Solve for t When it returns to its starting point, the time will be 2*t, using t from the first question. Calculate v at this time (...

**geometry**

tan 60 = 120/x; x = 120/tan60

**Chemistry..**

London dispersion force is a weak intermolecular force between two atoms or molecules in close proximity of each other. The force is a quantum force generated by electron repulsion between the electron clouds of two atoms or molecules as they approach each other. The London di...

**Math**

A = P *r*((1+r)^n)/((1+r)^n-1) where A = payment Amount per period P = initial Principal (loan amount) r = interest rate per period n = total number of payments or periods n = 30*12 = 360 P = 250000 4 = 0.045 A = 250000*0.045 * (1.045^360)/(1.045^360 - 1)

**Physic**

The tungsten filament emits white light, or the entire spectrum of colors of light. (look at any light bulb when its on). When the light is viewed with a spectroscope, it separates the white light into the different colors.

**math**

The formula for calculating the payment amount is shown below. A = P * ((r(1+r)^n)/(((1+r)^n)-1) Simple Amortization Calculation Formula where A = payment Amount per period P = initial Principal (loan amount) r = interest rate per period n = total number of payments or periods...

**statistics**

The probability of this combination occurring is (0.23^175) * (0.77 ^625)

**Math**

Δx/3*[f(x0)+4f(x1)+2f(x2)+4f(x3)+........+2f(xn−2)+4f(xn−1)+f(xn)] = 30/3 * (76 + 4*118 + 2*130 + 4*143 + 2*139 + 4*136 + 2*137 + 4*139 + 2*130 + 4*122 + 60)

**Chemistry**

The density of maple syrup is 1.33g/mL. a bottle of maple Syrup contains 740mL of syrup. What is the mass of maple syrup?

**geometry**

An arrow pointing to the bottom left

**math**

I think that you graph both; if you were asked to graph f>3 AND f< -2, there would be nothing to graph, because there is no intersection of the graphs. But because the selector is OR, you graph all the points for which f>3 (y > 3) or f<-2 (y<-2)

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