Wednesday

July 23, 2014

July 23, 2014

Total # Posts: 84

**c++**

how do you pass only part of an Array through a function? I thought it was something like function(Array, 5); but it's not working...

**diffeq**

how do i find the bifurcation for this: d^x/dt^2 = -.3 x - (x - 1)/((x - 1)^2 + a^2)^(3/2) - (x + 1)/((x + 1)^2 + a^2)^(3/2) we've tried using mathematica but it just runs forever...

**diffeq**

Let P(t) represent the population of a non-native species introduced to a new area for the purposes of harvesting. Suppose we intially introduce P0 = 100 indicidcuals and suppose the population grows exponentially with growth-rate coefficient k=2 if there is no harvesting (for...

**diffeq**

Suppose a species of fish in a particular lake has a population that is modeled by the logistic population model with growth rate k, carrying capacity N, and time t measured in years. Suppose the growth-rate parameter k=.3 and the carrying capacity N=2500. Suppose P(0)=2500. (...

**chemistry**

the rate law is R=k[Fe3+][I-]^2

**chemistry**

suggest a mechanism for 2Fe(3+) + 3I- -> 2Fe(2+) + (I3)-

**physics**

a very light rigid rod with a length of .500m extends straight out from one end of a meterstick. the meterstick is suspended from a pivot at the far end of the rod and is set into oscillation. determine the period of oscillation (hint: use the parallel-axis theorem) i can'...

**physics**

A car moves with speed v on a horizontal circular track of radius R. The height of the car's center of mass is h, and the separation between the inner and outer wheels is d. The road is dry, and the car does not skid. Find the maximum speed the car can have without overtur...

**chem lab**

If a sample tube was smudged with a fingerprint when inserted into a spectrometer, what affect would this have on the value of A (absorbance) when you read it? explain.

**stats**

Consider an infinite population with 25% of the elements having the value 1, 25% the value 2, 25% the value 3, and 25% the value 4. If X is the value of a randomly selected item, then X is a discrete random variable whose possible values are 1, 2, 3, and 4. (a) Find the popula...

**physics**

A bicycle has wheels 67.3 cm in diameter and pedal cranks 17.5 cm long. The cyclist pedals at a steady cadence of 76.0 rev/min. The chain engages with a front sprocket 15.2 cm in diameter and a rear sprocket 7.00 cm in diameter. Calculate: a) the speed of a link of the chain r...

**chem**

The solubility product of Mg(OH)2 is 1.2 x 10^-11. What minimum OH- concentration must be attained (for example, by adding NaOH) to decrease the Mg concentration in a solution of Mg(NO3)2 to less than 1.0 x 10^-10 M (molar)?

**chem**

which is the least stable isomer of C4H8: methyl cyclopropane or cyclobutane and why?

**chemistry**

which is more stable: methyl cyclopropane or cyclobutane and why?

**chem**

ever mind...i got it.

**chem**

The solubility of KNO3 is 155 g per 100 g of water at 75 degrees celcius and 38.0 g at 25 degrees celcius. What mass (in grams) of KNO3 will crystallize out of solution if exactly 100 g of its saturated solution at 75 degrees celcius is cooled to 25 degrees celcius. i found th...

**chem**

A hemoglobin molecule (molar mass =65000 g) can bind up to 4 oxygen molecules. In a certain experiment a .085-L solutoin containing 6.0 g of deoxyhemoglobin was reacted with excess of oxygen in a constant-pressure calorimeter of negligible heat capacity. calculate the enthalpy...

**chemistry**

The fuel value of hamburger is 3.6kcal/g. If a man eats 1 pound of hamburger for lunch and if none of the energy is stored in his body, estimate the amount of water that would have to be lost in perspiration to keep his body temperature constant. (the heat of vaporization of w...

**chemistry**

What hybrid orbitals are used by nitrogen atoms in the following specis: (a)NH3 (b)H2N-NH2 (c)NO3- I got sp^2 for (a), but I'm not sure about the other two.

**stats**

I have to do an observational study for an AP statistics course. Does anyone have any good ideas?

**quantum physics**

After a .800-nm x-ray photon scatters from a free electron, the electron recoils with a speed equal to 1.20 x 10^6 m/s. (a) What was the Compton Shift in the photon's wavelength? (b) Through what angle was the photon scattered? I got an answer for (a), but when i use it to...

**physics**

never mind. i got it.

**physics**

A construction worker uses a steep tape to measure the length of an aluminum support column. If the measured length is 18.700 m when the temperature is 21.2 degrees celcius, what is the measured length when the temperature rises to 29.4 degrees celcius. I found the increased l...

**statistics**

What is an example of two events that are neither disjoint nor independent? (I have no idea how that would even work)

**english**

is it underfunded or under funded?

**Physics**

use v^2=Vo^2 + 2*a*x

**gov't**

Does anybody know a site that rates the education systems of countries? I know Britain's number one...

**Calculus**

that one's arcsin. factor it into: 4*integral(1/sqrt(16-(t^2+2t+1)))dt so, 4*integral(1/sqrt(4^2+(t+1)^2))dt divide everything in the sqrt by 4^2 and bring it out as 1/4, 4/4*integral(1/sqrt(1+((t+1)/4)^s))dt) now it's in arcsin form (remember u and du) so your answer ...

**Calculus**

Actually, it's arctan. 3/10*integral(1/((x-1)^2+1))dx =3/10arctan(x-1) + C

**Calculus**

try factoring the bottom and using the triangle rule

**physics**

What are examples of when friction can increase an objects Kinetic Energy?

**physics**

for a free throw in basketball,find an equation for the final angle to go into the hoop in terms of y and x to the hoop and the initial angle. I can't seem to get an equation with only those variables. I always get stuck with others like time and velocity. how do i do this?

**calc**

Find m and b so that y=mx+b is a solution to the differential equation dy/dx=1/2x+y-1

**Calc**

Find the velocity of a satellite orbiting above the equator of the earth in geosynchronous orbit (Period=24 hours) in km/hr. The earth's mass M=5.974x10^(24)kg and radius R=6,731 km. G=6.673x10^(-11) m^3/(kg*s^2) Use v=(G*M/R)^(1/2) I plugged everything in and changed the ...

**Geometry**

The area of a trapezoid is H*(b1+b2)/2. 128=32*(5+x)/2 128=16(5+x) 8=5+x 8-5=x x=3 inches

**math/physics**

Help! I have no idea how to do this. The earth's orbit is nearly circular with a radius R=93x10^6 miles (the eccentricity is e=.017). Find the rate at which the earth's radial vector sweeps out area in units of ft^2/s. What is the magnitude of the vector J=rxr` for the...

**Geometry**

Complimentary angles add up to 90*. so 90-8=82 and 82/2 (b/c there's 2 x's) is 41. so the two angles are 41 and 49, the smaller one being 41*.

**works cited page**

I am doing a works cited page in MLA format. If I have two articles that are from the same website, just different places, do I document it as one source or two different ones?

**english**

I need to write 2 process essays. Any good ideas? I know there's so many things I can do, but it's hard to come up with a good one.

**Algebra II**

1st#=x-2 2nd#=x 1/2(x-2)+x=41 x-2+2x=82 3x=84 x=28

**French**

So actually the order of the words doesn't really matter in French?

**French**

I am not sure about the ordering of the words. Are the following correct? Do you speak French? Vous parlez francaise? I speak a little French. Je parle francais comme ci comme ca. My mom speaks french too. Ma mere parle francais aussi.

**French for Mischa**

Is this sentence correct? She has 3 male cousins and 4 female cousins. Elle a trois cousins et quatre cousines.

**French for Mischa**

We didn't need a french name for class, but Miche sounds nice. And thanks for doing this, I really appreciate it.

**French for Mischa**

Personally, I really like the sound of the language. And I always wanted to go to France, maybe travel or even for work. I am just really interested in French culture. I would love to know some of your 75 good reasons to learn french.

**French**

Wow, that's amazing!

**French**

I figured I rather do the accents by hand. lol Yeah, I am pretty sure where the accent goes. I was just wondering, how many languages do you know? You seem to know quite a lot.

**French**

Based on all the questions I've asked. I believe there are no mistakes in these sentences? -J'aime la musique japonaise. -J'ai un frere, il a vingt sept ans. -Elle a vingt ans. -Elle est jeune, elle est jolie. (Should I use jolie or belle?) -Elle aime la danse, le ...

**French**

When I say I have one brother and he is 27 years old, do I say J'ai un le fr¨¨re or J'ai un fr¨¨re Il a vingt sept ans.

**French**

Thanks, actually i just start learning french two weeks ago. I have a question from before, you said that the adjective modifies the noun in number (singular/plural) and gender (masculine/feminine) and has nothing to do with the subject. -la musique goes with française ...

**French**

I have to fill out this chart, I want to know did i do it correctly, thanks. Etre: Tu es Aimer: Tu aimes Habiter: tu habites s'appeler: tu s'appelles Parler: Tu parles

**French, for Mischa**

Thanks, SraJMcGin.

**Marketing**

no, i guess all kinds of pet food.

**French**

I have a PC and Windows

**French**

I remember that accent mark, I just don't know how to type it in. =) Thanks again.

**French**

And also, if a male says that he likes French music, so we also use francaise as in J'aime la musique francaise?

**French**

o...so there's nothing like le musique or le danse. I just have to remember the nouns, I get it now, thanks. And my textbook is called initial 1.

**French**

Thanks. I have another question. This sentence comes straight out of my textbook. Il aime la danse, la musique. Il is he, so why would it not be le danse, le musique?

**French**

I know that for a male to say that he is french, we use francais, and for a female, we use francaise. But when a female says that she speaks french, do we use francaise as in Je parle francaise? And when a female says that she likes French music, do we use francaise as in J...

**Algebra**

18-12x

**math**

What are you trying to do?

**Graph constraints**

Suppose that there is a model with two constraints 1) 120x1+160x2 <=(less than or equal to)450 2) 3x1+10x2 <= 25 and there is a third constraint called min. requirement, orginally this constraint is: 37x1+65x2 >= (greater than or equal to)120 I have to find all values...

**Graphs**

Suppose there's a model with 2 constraints originally. Now that another constraint is added. Which of the following are possible: 1) feasible region shrinks 2) feasible region stays the same 3) feasible region expands and Which of the following are possible: 1) optimal val...

**english**

I need a title for a narrative about my fear of snakes and the time one got loose in our classroom. Any witty ideas?

**pre-algebra**

a(a-c)=23 a-c=23/a c=a-23/a

**history/poetry**

Can anyone help me interpret this poem/prayer? What does it reveal about Mesopotamian religious beliefs and practices? Thanks!! May the wrath of the heart of my god be pacified! May the god who is unknown to me be pacified! May the goddess who is unknown to me be pacified! May...

**math**

(5x-20)(x+3) -(x^2-9)(x^2+9) Then are you sure the third one is written right? 18a^2b- is a to the 2b or is b something else

**english**

I'm suppose to figure out what the leg is a metaphor for in the following story. I can't figure it out. Any suggestions?! Letter from Gaza by Ghassan Kanafani Dear Mustafa, I have now received your letter, in which you tell me that you've done everything necessary ...

**calc- please help**

given x=2cos(t)+t*sin(t) and y=2sin(t)-t*cost(t), with t:[pi, 2pi] find all critical values. (4 answers)

**calc 2**

given x=2cos(t)+t*sin(t) and y=2sin(t)-t*cost(t), with t:[pi, 2pi] find all critical values. by finding dy/dx and setting it equal to zero, i only find one value, t=6.121, within that domain. that gives you x=.987. I'm suppose to get three other answers. How do i do this?!

**calc**

let y=2x-8. What is the minimum value of the product xy? I'm not really sure how to do this... I tried taking x*(2x-8), and the min is 0. but then i wanted to see if it was the same when solving for x, and i got a min of -8. How do i do this problem? thanks, but i found wh...

**physics**

I need to find the centripetal acceleration of my clothes dryer. How would I go about doing it... Would the tangential speed just be 2pi*R*number of rotations/time, or how would I find that? Put a shoe in the dryer. Count the number of times the shoe tumbles in a minute (that ...

**calc/physics**

A force of 250 N is required to stretch a spring 5m from rest. Using Hooke's law, F=kx, how much work, in joules, is required to stretch the spring 7m from rest? The energy required scales with x^2. Multiply 250 J by (7/5)^2.

**physics**

An electron and a proton are each placed at rest in an external uniform electric field of magnitude 520 N/C. Calculate the speed of each particle after 48 ns. None of the equations I have seem to help me. What can I use to solve this problem? I figured it out, but thanks anyway.

**physics**

Three point charges, q1, q2, and q3, lie along the x-axis at x=0, x=3 cm, and x=5 cm, respectively. Calculate the magnitude and direction of the electric force on each of the three points when q1=+6.0 muC, q2=+1.5 muC, and q3=-2.0 muC. I would add the forces. Watch direction. ...

**Calc AB**

What is the area of the region in the first quadrant enclosed by the graph of y=e^(x^2/4) and the line y=0.5? When I graphed the two functions they don't even connect so the answer would be infinity. What am I doing wrong> Integrate y=e^(x^2/4) from x=0 to the point whe...

**Calc**

Does 1/ln(x+1) converge or diverge? I've tried the nth term test, limit comparison test, and integral test. All I get is inconclusive. The other tests I have (geometric series, p-series, telescoping series, alternating series, and root tests) don't apply. What can I us...

**physics**

A bird perched on a swing the sits 8 cm below a bar has a mass of 52 g, and the base of the swing has a mass of 153 g. The swing and bird are originally at rest, and then the bird takes of horizontally at 2 m/s. How high will the base of the swing rise above its original level...

**Calculus**

Boats A and B leave the same place at the same time. Boat A heads due North at 12 km/hr. Boat B heads due East at 18 km/hr. After 2.5 hours, how fast is the distance between the boats increasing? You are looking at a right-angled triangle, let S be the distance between them Th...

**Calc**

The radius of a sphere is increasing at a rate proportional to its radius. If the radius is 4 initially, and the radius is 10 after two seconds, what will the radius be after three seconds? dR/dt = c R Integrating this differential equation gives you ln R/Ro = c t R/Ro = e^(ct...

**Math**

x/3=2 x=2*3 x=6 x/6=3 x=3*6 x=18 How would I get the missing number? ?/3 = 2 ?/6 = 3 What number divided by 3 will equal 2. Multiply 3 times two for the answer. Same for ?/6=3. what do u divide by to get 2 what u divide by to get 3

**Physics**

A worker pushes a 1500 N crate with a horizontal force of 345 N a distance of 24 m. Assume the coefficient of kinetic friction between the crate and the floor is .220. How much work is done by the floor on the crate? -M*g*(mu,k)*X Mg = 1500 N mu,k = 0.220 X = 24 m It is negati...

**Physics**

A student pulls on a rope attached to a box of books with a mass of 35.0 kg and moves the box up a ramp at 12 degrees with the horizontal. If the box starts from rest at the bottom of the ramp and is pulled at an angle 25.0 degrees with respect to the inclince and with a 185 N...

**calculus**

The volume of a solid is given by V=pi x^2(lnx)^2. what is the approximate change in the volume when x is increased from 2.718 to 3.000? dv= PI 2x(lnx)^2 dx + Pix^2 *2lnx * 1/x reduce that. For x, use 2.718 dx= 3-2.718 check my thinking.

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