Tuesday

April 21, 2015

April 21, 2015

Total # Posts: 631

**Chemistry**

2D2 + 1O2 --> 2D2O
*April 14, 2015*

**Math**

Find the radius of the circle if an arc of length 5 ft on the circle subtends a central angle of 135°. (Round your answer to two decimal places.)
*April 12, 2015*

**Chem pls!!!!!**

1) name one specific instance in which single displacement reactions can be useful. 2) zn + cucl --> cu + zncl2 in this reaction, a solid would be formed from the copper. what is the solid known as a ___________ please help me
*April 2, 2015*

**Physics **

A cart is moving at 1.01 m/s to the left has a head-on collision with a 28.5 kg cart traveling 2.04 m/s to the right. If the velocity to the first cart is 2.99 m/s to the right, what is its mass?
*March 23, 2015*

**science**

Calculate the average speed of a water molecule (with a mass of 3.0e-26 kg) on the surface of Venus (730 Kelvin).
*March 13, 2015*

**college physics**

When a thin 12.0cm iron rod moves with a constant velocity of 6.50m/s perpendicular to the rod, the induced emf across its ends is measured to be 0.300V. What is the magnitude of the magnetic field?
*March 13, 2015*

**English**

What does the following statement mean? "You can't rearrange the seats on a train"
*March 8, 2015*

**law/521**

this is what it says It's about Target's breach of data back in 2013. The whole case is about chapter 37, fiduciary duty of an officer/director. You need to write an explanation for each a about how the legal concepts the selected case can be applied within a business ...
*March 1, 2015*

**law/521**

doing paper on breach of data from target I dont understand the legal concepts that applied within a business managerial setting I know about the target part but not the rest
*March 1, 2015*

**science**

Paul threw a paper plane towards the west. The wind however caused the plane to move in a southwestern direction Which statement best describes the direction of the wind? (A) The wind is blowing f r o m the east. (B )The wind is blowing f r o m the west. (C) The w ind is ...
*February 18, 2015*

**math**

2 students are chosen at random from a group of 120 students that has 60 boys and 60 girls. What is the probability that the students are either both boys or both girls
*January 20, 2015*

**Geometry **

Does the angle-side relationship in triangles correspond with specific triangles or does it apply in all triangles?
*January 14, 2015*

**Derivative**

Evaluate the following: a) S (4x^2+3)/x^2 dx b) S 4x(x^2+3) dx Please help and show the working so that I can understand as I hv no foundation in derivative. TQ
*January 4, 2015*

**reimbursement**

New medicare payments systems and implementation of SC HI both came out to the? A. Balance budget act. B. Federal act 33-2 C. Retrospective payment system D. Health maintenance organization
*December 18, 2014*

**math**

what is the area of surface of revelution of function x= 1/3(y^2+2)^3/2 between the 1 <= y <= 2 ?
*December 17, 2014*

**Hrm/531**

Im doing a employment law complance plan and i need to know the principles and strategies that apply to the business
*December 6, 2014*

**Hrm/531**

principles and strategies for limousine service.
*December 6, 2014*

**English **

do these following sentences contain appositives? Most people, those of any age, enjoy music The core root of all the problems in the school, including uncleanliness of bathrooms and bad teachers, is the low budget given to the principal.
*November 25, 2014*

**Algebra HELP!**

Ryan is building matchstick square sequences, as shown ( first figure used 4, second figure used 7, third figure used 10, and the forth figure used 13). He used 599 matchsticks to form the last two figures in his sequences. How many matchsticks did he use in each of the last ...
*November 6, 2014*

**maths**

Calculate the amount that will be accumulated after 20 years if $1600 is invested at the beginning of every six months at 13.5% compounded semiannually
*November 3, 2014*

**Writing**

Thank You
*November 2, 2014*

**Writing**

Is "had" an example of a "to be" verb?
*November 2, 2014*

**physics**

A swimmer can swim in still water at a speed of 9.47 m/s. He intends to swim directly across a river that has a downstream current of 4.24 m/s. a) How many degrees from straight across the river should he head? Let upstream be a positive angle. Answer in units of ◦
*October 21, 2014*

**college algebra**

find the zeros of f,f(x) = 2x2 + x − 21 x= ? larger value x= ? smaller value
*October 19, 2014*

**college algeba**

Given r(x) = 6x x + 8 ,find the following. r(−1)= __ r(-3)= __ r(1/2)= __ r(0.1)=__ r(10,000)=___
*October 19, 2014*

**college algebra**

A manufacturer produces a product at a cost of $26.80 per unit. The manufacturer has a fixed cost of $500.00 per day. Each unit retails for $37.00. Let x represent the number of units produced in a 5-day period. Write the profit P as a function of x. (Hint: The profit function...
*October 19, 2014*

**college algebra**

A bus was purchased for $80,000. Assuming the bus depreciates at a rate of $6,000 per year (straight-line depreciation) for the first 10 years, write the value v of the bus as a function of the time t (measured in years) for 0 ¡Ü t ¡Ü 10. v(t)= _____
*October 19, 2014*

**Physics**

A northbound 3000 kg truck collides with an eastbound 2000 kg car. The two vehicles slide together as a single mangled object after the collision, and the direction of the slide is exactly northeast (45 degree angle between north and east). Which vehicle was going faster ...
*October 12, 2014*

**Biology**

Thank You
*October 11, 2014*

**Biology**

How can erosion effect the carbon cycle?
*October 11, 2014*

**Chemistry**

I do not know how to solve this problem. Could you show me how? You have a stock solution of 5.00M H3PO4. a.) What would be the concentration if 20.0mL of the stock solution is diluted to 250.0mL? b.) What volume of the dilute solution would you need if you needed 0.0200mol oh...
*October 7, 2014*

**chemistry**

If He(g) has an average kinetic energy of 7590 J/mol under certain conditions, what is the root mean square speed of F2(g) molecules under the same conditions?
*September 28, 2014*

**chemistry**

Hydrogen gas produced by this reaction is typically collected via water displacement, during which time the hydrogen gas becomes saturated with water vapor. If 238.4 mL of gas with a total pressure 1.27 atm was collected via water displacement at 29.4 °C, what is the ...
*September 27, 2014*

**chemistry**

Imagine there is a tank of unknown gas that contains 53.31% carbon, 35.51% oxygen, and 11.18% hydrogen by mass. At 35.0 °C and 0.470 bar, 2.0 L of the gas has a mass of 3.3 g. Using this information, answer the following questions. a.) What is the empirical formula of the ...
*September 27, 2014*

**chemistry**

A 8.50-g sample of solid AlCl3·6H2O was heated such that the water turned to steam and was driven off. Assuming ideal behavior, what volume would that steam occupy at 1.00 atm and 100.0 °C?
*September 27, 2014*

**chemistry**

Air is 78.1% nitrogen, 20.9% oxygen, and 0.934% argon by moles. What is the density of air at 22 °C and 760 torr? Assume ideal behavior.
*September 27, 2014*

**Biology**

Why does biomass decrease as we move up the biomass pyramid?
*September 27, 2014*

**science**

Is it possible that free Internet content might one day replace textbooks?
*September 13, 2014*

**physics **

A skydiver weighs 158 lb. When the skydiver reaches terminal speed, how much air drag does the skydiver experience?
*September 9, 2014*

**math**

2/5+1/10 is 5/10. But in my book it states that the answer is 7/15, without an explanation.
*August 15, 2014*

** math**

A jar contains four blues marbles and two green marbles. Without looking, two marbles are drawn from the jar. What is the probability that two marbles with the same color will be selected?
*August 15, 2014*

**Chemistry**

Orange juice clams that 200ml of their product contains 2.5 times the average daily allowance of Vitamin C. Calculate the average daily allowance of vitamin c (in mg) if the orange juice contains 0.040% (w/v) of vitamin C.
*July 28, 2014*

**math **

The product of two numbers is 35. one of the numbers is n, what expression represents the other number?
*July 9, 2014*

**science**

LIFE
*June 16, 2014*

**chem**

Three of the primary components of air are carbon dioxide, nitrogen, and oxygen. In a sample containing a mixture of only these gases at exactly one atmosphere pressure, the partial pressures of carbon dioxide and ni- trogen are given as PCO2 = 0.285 torr and PN2 = 593.297 ...
*May 30, 2014*

**chem**

A gas occupying 10 mL at standard conditions is heated to 10◦C while the pressure is reduced to 0.92114 atm. What is the new volume occupied by the gas? Answer in units of mL
*May 30, 2014*

**Chemistry**

Did I break this up correctly? NaHclO3 breaks into Na+ and HClO3-, and that further breaks into H+ and ClO3-
*May 28, 2014*

**chemistry**

Is that the right way to break down NaHClO3?
*May 28, 2014*

**chemistry**

NaHclO3 breaks into Na+ and HClO3-, and that further breaks into H+ and ClO3-, is that right?
*May 28, 2014*

**chemistry**

How did you get .99 for the molality value?
*May 27, 2014*

**chemistry**

Instead of NaCl, can I pick any other salt, as long as it has a Van't Hoff factor/ i value of 2?
*May 27, 2014*

**chemistry**

Something that will lower the freezing point of water to -3.7 degrees Celsius if one mole were placed in 1000 grams of water? To solve this I know I have to use the equation Tf= IKfm, Tf= 3.7, but how I go about the problem there if I don't know Kf or the the mole of ...
*May 27, 2014*

**chemistry**

M= mol/L, so it would be Liters x(mol/Liters), liters cancels out with liters so you are left with the amount of mols
*May 27, 2014*

**English**

Thank you, Ms. Sue! Housing is a very important issue.
*May 27, 2014*

**English**

Please Help!!! I just need some ideas to right a short essay. I've already though of allergies as one problem. Language Arts Essay: A law requiring everyone to have a pet might cause serious problems for some people. What problems do you thinks such a law could cause? In ...
*May 27, 2014*

**Chemistry**

What element(s) are more polarizable than oxygen? How can you tell? Wouldn't fluorine be most polarizable, because it is the most electronegative?
*May 26, 2014*

**Maths Probability**

5) 8
*May 20, 2014*

**math**

what is tan 3pi/4
*May 19, 2014*

**Maths Probability**

I am in need of the above soln if anybody knew solution please give answers...
*May 15, 2014*

**Algebra**

Let k(x) = -3.7e^0.8x + 8.2 Find the asymptote, y-intercept, k(-2), and k(6.25) 1. Asymptote = 2. Y - intercept = 3. k(-2) = (leave answer in terms of e) 4. k(6.25) = (leave answer in terms of e)
*May 12, 2014*

**History Re-post **

1) The essential question for the last few lessons asks "How did Canada seek to establish economic security and social justice from the period of the depression to the patriation of the Constitution? What kind of economic security did the Canadians seek? What kind of ...
*May 9, 2014*

**history **

1) The essential question for the last few lessons asks "How did Canada seek to establish economic security and social justice from the period of the depression to the patriation of the Constitution? What kind of economic security did the Canadians seek? What kind of ...
*May 9, 2014*

**statistics**

2.25
*May 9, 2014*

**Probability**

We are given the following statistics about the number of children in the families of a small village. There are 100 families: 10 families have no children, 40 families have 1 child each, 30 families have 2 children each, 10 families have 3 each, and 10 families have 4 each. ...
*May 1, 2014*

**Probability**

A single dot is placed on a very long length of yarn at the textile mill. The yarn is then cut into pieces. The lengths of the different pieces are independent, and the length of each piece is distributed according to the same PDF fX(x). Let R be the length of the piece that ...
*May 1, 2014*

**Probability**

Consider a Poisson process with rate λ. Let N be the number of arrivals in (0,t] and M be the number of arrivals in (0,t+s], where t>0,s≥0. In each part below, your answers will be algebraic expressions in terms of λ,t,s,m and/or n. Enter 'lambda' ...
*May 1, 2014*

**Probability**

All ships travel at the same speed through a wide canal. Each ship takes t days to traverse the length of the canal. Eastbound ships (i.e., ships traveling east) arrive as a Poisson process with an arrival rate of λE ships per day. Westbound ships (i.e., ships traveling ...
*April 30, 2014*

**Probability**

Can someone please answer?
*April 30, 2014*

**Probability**

In parts 1, 3, 4, and 5 below, your answers will be algebraic expressions. Enter 'lambda' for λ and 'mu' for μ. Follow standard notation. Shuttles bound for Boston depart from New York every hour on the hour (e.g., at exactly one o'clock, two o&#...
*April 30, 2014*

**Probability**

Suppose that you have two laptops, both of which you begin using at time 0. Each laptop will eventually fail, and we model each one's lifetime as exponentially distributed with the same parameter λ. The lifetimes of the two laptops are independent. One of the laptops ...
*April 30, 2014*

**Probability**

Fred is giving away samples of dog food. He makes visits door to door, but he gives a sample away (one can of dog food) only on those visits for which the door is answered and a dog is in residence. On any visit, the probability of the door being answered is 3/4, and the ...
*April 30, 2014*

**Astronomy**

12435
*April 25, 2014*

**Probability**

For any given flight, an airline tries to sell as many tickets as possible. Suppose that on average, 10% of ticket holders fail to show up, all independent of one another. Knowing this, an airline will sell more tickets than there are seats available (i.e., overbook the flight...
*April 23, 2014*

**Probability**

Let X be a continuous random variable. We know that it takes values between 0 and 3, but we do not know its distribution or its mean and variance. We are interested in estimating the mean of X, which we denote by h. We will use 1.5 as a conservative value (upper bound) for the...
*April 23, 2014*

**Probability**

For each of the following sequences, determine the value to which it converges in probability. (a) Let X1,X2,… be independent continuous random variables, each uniformly distributed between −1 and 1. Let Ui=X1+X2+⋯+Xii,i=1,2,…. What value does the ...
*April 23, 2014*

**Probability**

Let Θ be an unknown random variable that we wish to estimate. It has a prior distribution with mean 1 and variance 2. Let W be a noise term, another unknown random variable with mean 3 and variance 5. Assume that Θ and W are independent. We have two different ...
*April 20, 2014*

**Probability**

Consider a fire alarm that senses the environment constantly to figure out if there is smoke in the air and hence to conclude whether there is a fire or not. Consider a simple model for this phenomenon. Let Θ be the unknown true state of the environment: Θ=1 means ...
*April 20, 2014*

**Probability**

Manhole explosions (usually caused by gas leaks and sparks) are on the rise in your city. On any given day, the manhole cover near your house explodes with some unknown probability, which is the same across all days. We model this unknown probability of explosion as a random ...
*April 20, 2014*

**Probability**

???
*April 20, 2014*

**Probability**

Let N,X1,Y1,X2,Y2,… be independent random variables. The random variable N takes positive integer values and has mean a and variance r. The random variables Xi are independent and identically distributed with mean b and variance s, and the random variables Yi are ...
*April 20, 2014*

**Probability**

Let X be a random variable that takes non-zero values in [1,∞), with a PDF of the form fX(x)=⎧⎩⎨cx3 if x≥1, 0,otherwise. Let U be a uniform random variable on [0,2]. Assume that X and U are independent. What is the value of the constant c? c= P(X...
*April 20, 2014*

**Probability**

Let U, V, and W be independent standard normal random variables (that is, independent normal random variables, each with mean 0 and variance 1), and let X=3U+4V and Y=U+W. Give a numerical answer for each part below. You may want to refer to the standard normal table. What is ...
*April 20, 2014*

**Statistics**

1. For the following research question, specify the parameter and give the null and alternative hypotheses. "Is there a difference in the proportions of male and female college students who smoke cigarettes? 2. For the following research question, specify the parameter ...
*April 6, 2014*

**Probability**

The random variable X is uniformly distributed over the interval [θ,2θ]. The parameter θ is unknown and is modeled as the value of a continuous random variable Θ, uniformly distributed between zero and one. Given an observation x of X, find the posterior ...
*April 3, 2014*

**Probability**

c2 = 1
*April 3, 2014*

**Probability**

Let N be a geometric r.v. with mean 1/p; let A1,A2,… be a sequence of i.i.d. random variables, all independent of N, with mean 1 and variance 1; let B1,B2,… be another sequence of i.i.d. random variable, all independent of N and of A1,A2,…, also with mean 1 and ...
*April 3, 2014*

**Probability**

Let X=U+W with E[U]=m, var(U)=v, E[W]=0, and var(W)=h. Assume that U and W are independent. The LLMS estimator of U based on X is of the form U^=a+bX. Find a and b. Express your answers in terms of m, v, and h using standard notation. a=- unanswered b=- unanswered Suppose we ...
*April 3, 2014*

**Probability**

Caleb builds a particle detector and uses it to measure radiation from a remote star. On any given day, the number of particles, Y, that hit the detector is distributed according to a Poisson distribution with parameter x. The parameter x is unknown and is modeled as the value...
*April 3, 2014*

**Probability**

We have k coins. The probability of Heads is the same for each coin and is the realized value q of a random variable Q that is uniformly distributed on [0,1]. We assume that conditioned on Q=q, all coin tosses are independent. Let Ti be the number of tosses of the ith coin ...
*April 3, 2014*

**probability**

The lifetime of a type-A bulb is exponentially distributed with parameter λ. The lifetime of a type-B bulb is exponentially distributed with parameter μ, where μ>λ>0. You have a box full of lightbulbs of the same type, and you would like to know ...
*April 3, 2014*

**Probability**

Let T1,T2,…,Tn be i.i.d. observations, each drawn from a common normal distribution with mean zero. With probability 1/2 this normal distribution has variance 1, and with probability 1/2 it has variance 4. Based on the observed values t1,t2,…,tn, we use the MAP rule ...
*April 2, 2014*

**probability**

3. ?
*April 2, 2014*

**probability**

The vertical coordinate (“height") of an object in free fall is described by an equation of the form x(t)=θ0+θ1t+θ2t2, where θ0, θ1, and θ2 are some parameters and t stands for time. At certain times t1,…,tn, we make noisy ...
*April 2, 2014*

**Probability**

1. 1/3 2. 1/3 3. 2/3 4. p≤1/3: p
*April 2, 2014*

**Probability**

Let Θ be a Bernoulli random variable that indicates which one of two hypotheses is true, and let P(Θ=1)=p. Under the hypothesis Θ=0, the random variable X is uniformly distributed over the interval [0,1]. Under the alternative hypothesis Θ=1, the PDF of X ...
*April 2, 2014*

**Probability**

Alice has two coins. The probability of Heads for the first coin is 1/3, and the probability of Heads for the second is 2/3. Other than this difference, the coins are indistinguishable. Alice chooses one of the coins at random and sends it to Bob. The random selection used by ...
*April 2, 2014*

**Probability**

A defective coin minting machine produces coins whose probability of Heads is a random variable Q with PDF fQ(q)={3q2,0,if q∈[0,1],otherwise. A coin produced by this machine is tossed repeatedly, with successive tosses assumed to be independent. Let A be the event that ...
*April 2, 2014*

**Biology**

Why does an increase in light intensity cause the rate of photosynthesis to increase?
*March 26, 2014*