The homework help thread...(SERIOUS)

[BandApart]

anyone good at doing related rates....if so, will post question, due in 30 minutes.


edit

A runner sprints around a circular track of radius 130 m at a constant speed of 7 m/s. The runner's friend is standing at a distance 260 m from the center of the track. How fast is the distance between the friends changing when the distance between them is 260 m? (Round to 2 decimal places.)

[whitesox3223]

whats the difference between emigration and immigration?

And does the us have net in-migration or net out?

google.com

[Davidthefat]

jesus david, stop coding this **** LOL ur 15, this is not allowed!

Its pretty damn messy, I should clean it up by putting in classes and stuff, but need to get the collision working before I can clean up the file abit

[Magsy]

Its pretty damn messy, I should clean it up by putting in classes and stuff, but need to get the collision working before I can clean up the file abit

If you organize it into classes it would make debugging it a whole lot easier. You'll be able to pinpoint which parts work etc. Also, it would make it a lot easier to read... Is that C-language btw?

[Davidthefat]

If you organize it into classes it would make debugging it a whole lot easier. You'll be able to pinpoint which parts work etc. Also, it would make it a lot easier to read... Is that C-language btw?

 //Map Collision
        
        if(bass_bb_bottom > cmap_top[(y + endY[frame])/40][x/40] && map_col[(y + endY[frame])/40][x/40] == 1)
        {
        collision = true;
        }
        
        else if(bass_bb_top < cmap_bottom[(y - endY[frame])/40][x/40] && map_col[(y - endY[frame])/40][x/40] == 1)
        {
        collision = true;
        }
        
        else if(bass_bb_right > cmap_left[y/40][(x + endX[frame])/40] && map_col[y/40][(x + endX[frame])/40] == 1)
        {
        collision = true;
        }
        
        else if(bass_bb_left < cmap_right[y/40][(x - endX[frame])/40]&& map_col[y/40][(x - endX[frame])/40] == 1)
        {
        collision = true;
        }

Finally fixed it, now time to clean it up into classes

[OldGreg21]

ok brahs I need some help on AP Calculus AB stuff. Both problems are mainly on extrema, critical numbers, derivatives, you get the idea. Here's the first one:

f(x) = X^4 - 4X^3

I know how to find f prime and double prime, but I'm not sure how to find the critical numbers of f (the original equation shown up above). Also, how do you find the inflection points? do you set whatever you got for f double prime equal to zero and solve?

Here's the second problem:

f(x) = square root of 3 times sinx + cosx

Find where f is increasing and decreasing by using f prime. Then find f double prime to determine where f is concave up and concave down.

If any of you guys can help me on this, I will love you forever (ok not like that but maybe reps involved?) Thanks!

[Snackxmachine]

ok brahs I need some help on AP Calculus AB stuff. Both problems are mainly on extrema, critical numbers, derivatives, you get the idea. Here's the first one:

f(x) = X^4 - 4X^3

I know how to find f prime and double prime, but I'm not sure how to find the critical numbers of f (the original equation shown up above). Also, how do you find the inflection points? do you set whatever you got for f double prime equal to zero and solve?

Here's the second problem:

f(x) = square root of 3 times sinx + cosx

Find where f is increasing and decreasing by using f prime. Then find f double prime to determine where f is concave up and concave down.

If any of you guys can help me on this, I will love you forever (ok not like that but maybe reps involved?) Thanks!

to find "f" prime and double prime, I believe you first do the derivative on the equation once and twice. To find the critical numbers just make both equations equal to zero and find "x"

[Mr.Roarke]

how do catalysts affect the energy required for a (chemical) reaction to take place?

reps are ready.

[goosefrabaz99]

how do catalysts affect the energy required for a (chemical) reaction to take place?

reps are ready.

catalysts help the reaction occur..in essence, they give the products a bit more push in reacting. Thus, with the use of catalysts, less energy is required for a reaction to occur.

[willieb925]

given the table, how do i find the numerical value of the marginal propensity to consume?

took me 45 mins but i got it

change in consumption/change in real gdp

[TheSoldier]

translate this into spanish, reps for life

"SENTENCES

Argentina is the 8th largest country in the world and 2nd largest in the world.

The countries that surround/boarder Argentina is Republic of Chile, Federative Republic of Brazil, Oriental Republic of Uruguay, Atlantic Ocean, Republics of Bolivia and Paraguay.

Its total area is approximately 2.7 million km².

Argentina’s land is made up of mountains, plateaus, plains, forest.

The mountains in Argentina are some of the tallest in world, including the Cerro Aconcagua which is 6,960m tall

The Cerro Aconcagua is the tallest mountain in the Western Hemisphere.

North Part of Argentina is very hot and humid in the summers, and milder in the winters

Central Part of Argentina wet and hot summers, and cool winters.

South Argentina has warm summers and cold winters.

Pampas: This is the plains west and south from Buenos Aires

Gran Chaco: The Gran Chaco regian in the northern part of the country is seasonal dry and wet.

Mesopotamia: The land between the Parana and Uruguay rivers is called Mesopotamia.

Cuyo: West-Central Argentina is covered by Andres Mountains. To the east of that is the Cuyo region. "



iinb4googletranslators

[Sit]

translate this into spanish, reps for life

"SENTENCES

Argentina is the 8th largest country in the world and 2nd largest in (SOUTHERN AMERICA).

The countries that surround/boarder Argentina (ARE: ) (THE) Republic of Chile, Federative Republic of Brazil, Oriental Republic of Uruguay, Atlantic Ocean, Republics of Bolivia and Paraguay.

Its total area is approximately 2.7 million km?ƒ‚?‚².

Argentina’s land is made up of mountains, plateaus, plains, forest.

The mountains in Argentina are some of the tallest in world, including the Cerro Aconcagua which is 6,960m tall

The Cerro Aconcagua is the tallest mountain in the Western Hemisphere.

North Part of Argentina is very hot and humid in the summers, and milder in the winters

Central Part of Argentina (HAS) wet and hot summers, and cool winters.

South Argentina has warm summers and cold winters.

Pampas: This is the plains (SOUTHWEST) from Buenos Aires

Gran Chaco: The Gran Chaco (REGION) in the northern part of the country is seasonal dry and wet.

Mesopotamia: The land between the Parana and Uruguay rivers is called Mesopotamia.

Cuyo: West-Central Argentina is covered by Andres Mountains and to the east of that is the Cuyo region. "



iinb4googletranslators

First of all i fixed most of it in english.

[alpha_rower_1]

Synthesis Reactions:

Complete the synthesis equations and balance
Mg + N2 --->
Al + F2 --->
K + O2 --->
Cd + I2 --->
Cs + P --->

In Highschool chem I found a site, I think it was something like chemmybear.com or something like that, but it had hundreds of reaction some of them might be there, it has been 3 years since I have done a lot of this stuff so my memory is a little iffy on the site name. I usually would go there and go to the answer sheet and just type in your reaction in the search on page tool, and see if the reaction pops up, if so you have your answer.

so what I got was
magnesium nitride (3Mg+N2--->Mg3N2)
the rest I leave to you

[alpha_rower_1]

All of this is wrong

i^i = e ^ (-pi/2)

For a quick proof, use what you know about basic exponential and logarithmic expansions and euler's identity. A few easy comments and modifications will make it a rigorous proof. But I'm guessing noone cares about the proof...so that's what the answer is. It is right.

could you explain that proof, because I am struggling with this e^(j*pi)+1=0
e^(j*pi)=-1===>j*pi=ln(-1)... ln(-1)=e^(j*pi/2)*pi...j*pi=e^(j*pi/2)*pi==>j=e^(j*pi/2)

so j^j would be (e^(j*pi/2))^(e^(j*pi/2)) how does this simplify to e^(-pi/2)?

do you have to use this identity? e^(j*pi*x)=cos(pi*x)+j*sin(pi*x)?

[Vodkilis]

ok brahs I need some help on AP Calculus AB stuff. Both problems are mainly on extrema, critical numbers, derivatives, you get the idea. Here's the first one:

f(x) = X^4 - 4X^3

I know how to find f prime and double prime, but I'm not sure how to find the critical numbers of f (the original equation shown up above). Also, how do you find the inflection points? do you set whatever you got for f double prime equal to zero and solve?

Here's the second problem:

f(x) = square root of 3 times sinx + cosx

Find where f is increasing and decreasing by using f prime. Then find f double prime to determine where f is concave up and concave down.

If any of you guys can help me on this, I will love you forever (ok not like that but maybe reps involved?) Thanks!

1.) F(x) = x^4 - 4x^3
F'=4x^3-12x^2 = 4x^2(x - 3)
Critical Values = 0,3
Set up a number line: <-----0-----3----->
Plug in numbers between each values to find when the first derivative is negative/positive.

X < 0, Negative
0<x<3, Negative
X>3, Positive

Minimum at x = 3

F"=12x^2 - 24x = 12x(x - 2)
Critical Values = 0, 2
Set up number line: <---0---2--->
Plug in numbers between each values again to find negative/positive.

x<0, Positive, Concave Up
0<x<2, Negative, Concave Down
X>2, Positive, Concave Up

2.) Is it (Squareroot 3)(sinx + cosx) or are they all under the square root?

[alpha_rower_1]

how do catalysts affect the energy required for a (chemical) reaction to take place?

reps are ready.

catalysts lower the activation energy. If you want to think of an exothermic reaction, you are pushing a ball up a gentle hill until you reach the top, that would be your activation energy or the energy required to start the reaction. Once the ball rolls down the hill that is the exothermic part of the reaction. The catalyst basically makes the hill "shorter" ie less energy to start the reaction rolling.

[strac]

Explain the role of phospholipids in the struture and functioning of cell membranes. (4 marks)

*reps*

[OldGreg21]

Fruit Flies phenotypes, AP Biology 2003 question 1?
This is from the AP Biology 2003

1. In fruit flies, the phenotype of eye color is determined by a certain locus. E indicates the dominant allele and e indicates the recessive allele. The cross between a male wild-type fruit fly and a female white-eye fruit fly produced the following offspring.

F1

Wild type Male =0
Wild type Female= 45
White-eyed Male= 55
White-eyed Female= 0
Brown eyed Female= 1

The wild type and white eyed individuals from the F1 generations were crossed to produce the following offspring

F2


Wild type Male =23
Wild type Female=31
White-eyed Male= 22
White-eyed Female= 24
Brown eyed Female= 0


(a) Determine the genotypes of the original parents and explain your reasoning. You may use Punnet squares to enhance your description, but the results from the Punnett squares must be discussed in your answer.

[scarboro]

Fruit Flies phenotypes, AP Biology 2003 question 1?
This is from the AP Biology 2003

1. In fruit flies, the phenotype of eye color is determined by a certain locus. E indicates the dominant allele and e indicates the recessive allele. The cross between a male wild-type fruit fly and a female white-eye fruit fly produced the following offspring.

F1

Wild type Male =0
Wild type Female= 45
White-eyed Male= 55
White-eyed Female= 0
Brown eyed Female= 1

The wild type and white eyed individuals from the F1 generations were crossed to produce the following offspring

F2


Wild type Male =23
Wild type Female=31
White-eyed Male= 22
White-eyed Female= 24
Brown eyed Female= 0


(a) Determine the genotypes of the original parents and explain your reasoning. You may use Punnet squares to enhance your description, but the results from the Punnett squares must be discussed in your answer.

Since there are no White-eyed Female, the p1 male is dominant E.
All males being white eyed XeY means the female p1 is XeXe and this is an X-inherited gene.
No white eyed females also tell us the entire f1 female is XeXE meaning the female p1 can only be XeXe.

Basically a cross between M(XEY) and F(XeXe)
The trait is only X chromosome regulated means the fathers genotype is useless to sons and not passed on.

btw wtf u 21 doin AP bro?

[F.Liu]

catalysts lower the activation energy. If you want to think of an exothermic reaction, you are pushing a ball up a gentle hill until you reach the top, that would be your activation energy or the energy required to start the reaction. Once the ball rolls down the hill that is the exothermic part of the reaction. The catalyst basically makes the hill "shorter" ie less energy to start the reaction rolling.

You are wrong.

Catalysts are substances that, when used in a reaction, provide an alternate pathway for the reaction to occur, and this alernate pathway has a lower activation energy. It may be used in the reaction but is (ideally) regenerated in the end.

A simpler way to describe it is if you know what a Maxwell Boltzmann distribution looks like (google it if not)--there is a place where the activation energy lies. Using a catalyst would cause the activation energy in that particular reaction to be shifted left, on the curve, thereby incorporating a higher fraction of particles that have a sufficient energy to react.

Also, as possibly trivial info, catalysts can be used to slow down reactions as well.

[spladle29]

anybody wanna do my art history research paper on rene magritte? didnt think so.

[yondy12]

um apparently we have to balance these equations and i have no clue how
can someone explain it to me?

1) H2O + NaF ----> HF + Na2O
2) Br2 + FeT3 ----> Fe + BrI3 ----> FeBr3 + I2

[iamme098]

um apparently we have to balance these equations and i have no clue how
can someone explain it to me?

1) H2O + NaF ----> HF + Na2O
2) Br2 + FeT3 ----> Fe + BrI3 ----> FeBr3 + I2

You wanna have the same number of each element on both sides of the equation.

So for the first one, you have 2 Hydrogens on the left but only one on the right, so adding a two in front of the HF will balance the hydrogens. But now there are 2 F's on the right and only one on the left, so you gotta balance those now too. You gotta keep playing with it until they all even out, which they will.

One thing to remember is, generally, you wanna try to balance the most complicated molecule first, then work your way down to the least complicated.

[andthenithitme]

Need to know how to do the problem already have the answer
1. How many grams are there in 1.5x10^25 molecules of CO^2
answer: 1.1x10^3
2. What volume would the CO^2 in Problem 1 occupy at STP?
answer 5.6x10^2
3. A sample of NH^3 gas occupies 75.0 liters at STP. How many molecules is this?
answer 2.02x10^24
4.What is the mass of the sample of NH^3 in problem 3?
answer: 5.69x10^3
5. How many atoms are there in 1.3x10^22 molecules of NO^2?
answer 3.9x10^22
6. Determine the volume of a 5.0g sample of O^2?
answer: 3.5
7a. How many molecules of O^2 are in the container in problem 6?
answer 9.4x10^22
7b. How many oxygen atoms are in the container in problem 6?
answer 1.9x10^23

[scarboro]

Need to know how to do the problem already have the answer
1. How many grams are there in 1.5x10^25 molecules of CO^2

5x10^25molecules/avogadros number=#mols
#mols*molar mass=grams of CO2
answer: 1.1x10^3
2. What volume would the CO^2 in Problem 1 occupy at STP?
answer 5.6x10^2
#mols*standard volume at STP per mol of gas
3. A sample of NH^3 gas occupies 75.0 liters at STP. How many molecules is this?
answer 2.02x10^24

75litres/standard volume at STP per mol of gas=#mols
#mols*avogadros number=# of molecules
4.What is the mass of the sample of NH^3 in problem 3?
answer: 5.69x10^3
#mols*molarmass= mass
5. How many atoms are there in 1.3x10^22 molecules of NO^2?
answer 3.9x10^22
since the compound is NO2, it has 3 elements therefore per molecule there are 3 atoms
so # of atoms=#of elements*molecules
=1.3x10^22 *3=3.9x10^22
6. Determine the volume of a 5.0g sample of O^2?
answer: 3.5
5g/molar mass= # of mols
#mols*standard volume at STP of one mol of gas=volume of sample

7a. How many molecules of O^2 are in the container in problem 6?
answer 9.4x10^22
#mols*avogadros number=#of molecules
7b. How many oxygen atoms are in the container in problem 6?
answer 1.9x10^23
=#of molecules *2oxygen atoms per molecule=#of oxygen atoms

standard volume of 1mol of gas at STP is 22.4 btw
also I have to comment that chemistry is gay

[TheLostSim1718]

Hey everyone, could you please help with me Morte d'Arthur? We have read the story and i have a test on the story tomorrow but you know it is written in old english. Could someone please give me a modern english translation to understand better? Thank you in advance and i will rep you.

[iamme098]

Need to know how to do the problem already have the answer
1. How many grams are there in 1.5x10^25 molecules of CO^2
answer: 1.1x10^3
2. What volume would the CO^2 in Problem 1 occupy at STP?
answer 5.6x10^2
3. A sample of NH^3 gas occupies 75.0 liters at STP. How many molecules is this?
answer 2.02x10^24
4.What is the mass of the sample of NH^3 in problem 3?
answer: 5.69x10^3
5. How many atoms are there in 1.3x10^22 molecules of NO^2?
answer 3.9x10^22
6. Determine the volume of a 5.0g sample of O^2?
answer: 3.5
7a. How many molecules of O^2 are in the container in problem 6?
answer 9.4x10^22
7b. How many oxygen atoms are in the container in problem 6?
answer 1.9x10^23

Look at my previous post in this thread about PV=nRT. That + Avogadro's number will help you with all of them.

[Airror]

site that balances chemical equations

http://www.gregthatcher.org/Chemistr...x?StartsWith=H

[TheLostSim1718]

lol @ no one helping me.

[benzz]

lol @ no one helping me.

cuz u a *******