Friday

July 25, 2014

July 25, 2014

Total # Posts: 166

**Math**

Find the roots by factoring. 25x squared - 30x= -9

**Mathamatics**

Solve the following trigonometry identities. a) 1-cos2(theta) = sin(theta)cos(theta)/cot(theta) b) (1-cos2(theta))(1-tan2(theta))=sin2(theta)-2sin4(theta)/1-sin2(theta) *its supposed to be cos to the power of two, sin to the power of four, etc. There is also supposed to be a t...

**Chemistry **

Could you please explain how electronegativity works and how you find the total electronegativity value of PO3 K2O H2S GIVEN: P- 2.1, O-3.5, K- 0.8, H- 2.1, and S- 2.5 Also how to you tell if the compound is ionic, polar covalent, or non polar covalent? Thank you!!!

**Chemistry **

How can you tell that CO2 has a dipole moment while O2, N2, and HCL does not?

**Chemistry**

Could you please explain how electronegativity works and how you find the total electronegativity value of PO3 K2O H2S GIVEN: P- 2.1, O-3.5, K- 0.8, H- 2.1, and S- 2.5 Also how to you tell if the compound is ionic, polar covalent, or non polar covalent? Thank you!!!

**math**

96 diveded by 3

**math trig**

If a ferris wheel with a 20.5 meter radius, how high would one car be from the loding dock at these given angles trveled by the rider?: 90 135 180 225 270 315 405 450 495 and 540?

**math trig**

If a ferris wheel has a radius of 20.5meters, how tall would a 45 degree angle be?

**Math-Calculus**

Consider two ships which are joined by a cable attached to each ship at the water line. Suppose the two ships are 200 metres apart, with the cable stretched tight and attached to a pulley which is anchored halfway between the ships at a depth of 45 metres. If one ship moves aw...

**Physics**

A 4.10 m long, 590 kg steel beam extends horizontally from the point where it has been bolted to the framework of a new building under construction. A 66.0 kg construction worker stands at the far end of the beam. What is the magnitude of the torque about the point where the b...

**math**

The perimeter of a rectangular playground is 40 yards. It is 1.5 yards longer that it is wide. What is area of playground?

**math**

The perimeter of a rectangular playground is 40 yards. It is 1.5 yards longer that it is wide. What is area of playground?

**Geography **

The G8 countries are responsible for 62% of the carbon dioxide emission into the earths atmosphere. Should I classify this as worrying or human changes

**Algebra**

I just guessed and checked for this one, but the answer is Karen will be 18, and Susan will be 27.

**science (revision)**

I have a test on electricity on Friday and I wandering if I could get a basic summary of what I should know. I'm British so I don know what grade I am but I'm 11 so aound that sort of basic level please!!! Thanks.

**Math**

A cup of coffee costs 80c less than a burger.Together they cost 220c. Use this information to form an equation and solve it. This question I can't get my head around. It's due in 2 days but I would like to get it done sooner. Thanks.

**physics**

A large water tank is 18m above the ground. Suppose a pipe with a diameter of 8cm is connected to the tank and leads down to the ground. How fast does the water rush of the piper at ground level? Assume that the tank is open to the atmosphere.

**Math**

Jen and Heather went to lunch. When the bill came, Jen discovered that she only had $8. Luckily, Heather had enough money to pay the other part, 3/5 of the bill. How much did Heather pay? How much was the total bill? I'm having a hard time understanding the steps in gettin...

**physics**

wave speed: the violin is a four stringed instrument tuned so that the ratio of the frequencies of adjacent strings is 3:2. (This is the ratio when taken as high frequency to lower frequency.) If the diameter of E string (the highest frequency) on a violin is 0.25 mm, find the...

**physics (SOS!)**

a cylinder that is 20 cm tall is filled with water. If a hole is made in the side of the cylinder, 5cm below the top level, how far from the base of the cylinder will the stream land? Assume that the cylinder is large enough so that the level of the water in the cylinder does ...

**physics**

A block of wood will sink 10 cm in freshwater. How far will it sink in seawater. The specific gravity of seawater is 1.025. I'm confused as to how to approach to problem

**physics**

why is work done during the rise= mgh directly?

**physics**

(a) a spherically shaped buoy is made from wood, which has a specific gravity of 0.6. find the acceleration of the buoy when released from rest at the bottom of a freshwater lake. (b) if the buoy starts out 10 m below the surface of the water, determine the height above the wa...

**chemistry**

If 4.83 mL of an unknown gas effuses through a hole in a plate in the same time it takes 9.23 mL of argon, Ar, to effuse through the same hole under the same conditions, what is the molecular weight of the unknown gas?

**chemistry**

A sample of natural gas is 85.2% methane, CH4, and 14.8% ethane, C2H6, by mass. What is the density of this gas mixture at 18.0°C and 771 mmHg? Assume ideal gas behavior.

**math**

E4EW45WE45W4

**mathematics of finance**

solve; FV=7,000;i=0.03;PMT=$400;n=?

**algebra**

what is the answer of 7h+2w-9h-8w

**social studies**

ethnic group

**chem**

.144

**Math**

A student wants to display the average monthly temperatre for one year.He chooses a line graph to display the data.Describe and correct the error made in choosing that type of display for the data.

**Math**

Which sample is more likely to be biased? Should big bend state park restrict the number of campers allowed on the grounds? a.70 randomly selected visitors to Big Bend State Park b.70 randomly selected campers at Yosemite National Park

**Math**

Should the city build a homeless shelter downtown?Which sample is more likely to be biased? a.60 randomly selected downtown resturant customers b.60 randomly selected people at the post office

**Math-Corrections**

I'm not sure ,but now i got the answer no because she(the librarian)cant prove that the kids will not like the new encyclopedia.

**Math-Corrections**

Based on the survey,the librarian predicts that about two-thirds of the students in seventh grade will not like the new encyclopedia.Is this answer reasonable? Answer i got:yes

**meanings**

Musical?

**Chemistry**

What is the complete chemical equation? Al(s) + Cu(CH3COO)2(aq) -> ?

**Math help quickly**

Use the expressions for left and right sums and the table below. right-hand sum = summation (n above and i =1 on the bottom) f(ti) * change in t = f(t1) * change in t + f(t2) * change in t + .... + f (tn) * change in t left-hand sum = summation (n above and i = 0 on the bottom...

**Calculus need help badllyyy!**

Use the expressions for left and right sums and the table below. right-hand sum = summation (n above and i =1 on the bottom) f(ti) * change in t = f(t1) * change in t + f(t2) * change in t + .... + f (tn) * change in t left-hand sum = summation (n above and i = 0 on the bottom...

**4th grade math**

what is 5/6 of 288

**4th grade math**

what is 5/6 of 288

**Chemistry**

What is the magnitude of the energy change associated with the emission of one mole of photons of light* with this wavelength? light*= 6.231×1014 Hz

**MATH**

2+2+1+1=6cm2

**Chemistry**

Determine the partial pressure of oxygen necessary to form an aqueous solution that is 7.7 x 10-4 M O2 at 25oC. The Henry's Law Constant for oxygen in water at 25oC is 1.3 x 10-3 M/atm

**Chemistry**

Find the product for the equation and then write a balanced equation. Cl2 + FeBr3 -> ?

**chemistry**

I need to convert a word problem that I was given into a balanced chemical equation and cannot figure out how i was type it. The problem is: Nitrogen and hydrogen gases react at extreme temperatures and pressures. Any help?

**math**

Puck is making a scale model of an airplane. The actual airplane is 98 feet long. The scale of the model is 1 cm : 4.7 ft. What is the length of the model? [Round to the nearest hundredth, if necessary.]

**Chemistry**

In respect to covalent bonding, what does it mean if there's an unshared or lone pair of electrons?

**Science**

A circular hatch in the hull of a submarine has a radius of 40.0 cm. The submarine is 850.0 m under water. If atmospheric pressure above the ocean is 1.01 x 105 Pa and the air pressure inside the submarine is 1.31x 105 Pa, what net force is exerted on the hatch? (ρsw = 10...

**chemistry**

A gaseous mixture containing 5 moles of H2 and 7 moles of Br2 reacts to form HBr. Write a balanced chemical equation. Which reactant is limiting? What is the theoretical yield in moles? What is the theoretical yield for this reaction in grams? How many moles of excess reactant...

**calculus**

i'm not sure how to do this. can someone help, please? thanks! consider the function f(x0 = x^2 + 2x on the interval [-2, 2] a. draw a sketch of the graph of f(x). find the average rate of change on the interval [-2, 2] and sketch this secant line. b. find an expression th...

**English**

essay "peace and stability in a globalized world" I need some help. Thanks

**Math**

Typing error fing meaning find

**Math**

How do I fing volume of a shape?

**calculus**

let f(t) = 2*pi*t + sin(2*pi*t) a) find value of t in open interval (0,2) for which the tangent line at (t, f(t)) is parallel to the line through (0,0( and (2, 4pi) b) suppose the given funtion describes the position of a particle on the x-axis for 0<= t <= 2. What is th...

**calculus**

find the centroid of the plane region bounded by the curves y = cos x, y=sinx, x=0,

**English**

I need to know what just means in the following Sentance . Do you think this is just Please help even my mom is blank Tx

**English**

I'm blank on this question From the verbs listed write a noun ending in ion Divide Explode. Collide Confess. Invade. Rotate Comprehend. Deflect I don't need all the answers I just need to know what it means Thanks

**Non verbal reasoning age 9-10**

I really hate nvr it's horrible. I'm English so we have to do this I don't know if any Americans do it but I still hate it. For anyone who docent know what it is, it's basically pictures that mean something , but get changed ur ment to circle the answer . Any a...

**Fourth grade math**

Tx fo helping

**Fourth grade math**

What's range mean?

**English**

For our homework we had to draw and label an imaginary creature, then write an essay on it . I'm completely stuck on the essay bit please he

**English**

What word is wrong in this sentence ? Darren wusai and I is a good team. Please help I need this in in about six hours time!

**English**

Wow ! I thought it wasn't that simple as of being an opposite thanks I'm saved!

**English**

Really stuck on English homework.ahhhh! What is an antonym for the following words? Subtract Extend Spectator Least Confident Exterior Please, help despretly needed by Monday !

**english**

I'm not sue but I would put who because it's a simpler word

**English check my answer**

I'd just say I'm really bad at grammar and tell your teacher , can I have some extra help please? Sweet talking into thinking you love English always works

**Social Studes**

Hhhhhheeeeeellllllppppppppp mmmmmmeeeeeee oooooooonnnnnnn this

** Math**

I am a number with the same number of tens as ones. The sum of my digits is less than 5. Is am a number greater than 15. What number am i?

**4th grade Math Help**

hi, what is the least possible number, when rounded will become 1,000,000? would it be 999,999?

**calculus**

fin derivative of the function (t+e^t)(4- sqrt t)

**calculus**

differentiate the following funcation: R(t) = (t + e^t)(4- sqrt (t))

**calculus**

f(x)= (4x^2+5)/(3-2x) find derivative using limit

**calculus**

given the function f(x) = { x^2+2 if X<=2, 3 if x=2 and 4-x if x>= 2 -> graph f(x)

**math**

how do you do 16n-9 with the specials

**Physics**

A projectile is launched beneath the straight line path it would follow if there was no gravity. How many metres does it fall below the line if it has been travelling for 1 second? 2 seconds?

**Calculus**

Write the logarithm of a single quantity: 2ln(x)+ln(4)-(1/2)ln(9)

**math (plz help)**

1. 46 seats...... 30+4+4+4+4 2. No the 8th row has 62 seats and the 7th row has 58 (30+4+4+4+4+4+4+4+4) 3.THeater B has 145 seats.... (40+25 4's) hope that helped

**chemistry.**

i've tried to di it. 1)Na2CO3 + HCl---> NaCl+NaHCO3 2)Basic as Na2CO3 is a base and amount of HCl =0 3)NaHCO3+HCl--->NaCl+CO2+H2O 4)phenolphthalein for eq pint point 1 as it will indicate change in basicity and methyl orange for secong equivalnce point as it will ind...

**chemistry.**

in the titration between Na2CO3 and HCl... 1) at the first end point what reaction is stoiciometrically complete? 2)At the start of titration where HCl=0 is the solution acidic or basic. ExPlain? 3) At the 2nd end point what reaction is stiociometrically complete? 4)Propose a ...

**chemistry urgent**

Draw major product of substitution reaction of (2R,3S)2-bromo-3-methylpentane with CH3CH2O- nucleophile

**Organic chemistry**

Draw major product of substitution reaction of (2R,3S)2-bromo-3-methylpentane with CH3CH2O- nucleophile?

**science**

anyone gonna help?

**science**

I'm in 5th grade and I need a cool, unusual science fair project. I have 3 days to do this. It has to be a question with a variable, not a demonstration. HELP!

**banyan elementary**

7x12=84

**space**

How many socks would it take to fill the space shuttle

**biology**

21% of a population is homozygous dominant, 49% are heterozygous and 29% are homozygous recessive. if the Hardy-Weinberg Law applies, what percentage of the next generation is predicted to be homozygous recessive?

**math**

How do you find the unit rate for this? The managerof Quality Dairy stores says it takes 1000 pounds of milk to make 100 pounds of cheddar cheese. Find a unit rate relating pounds of milk (m) to pounds of cheese (c). 1000 pounds of milk per 100 pounds of cheese.

**math**

find the values of x and y that solve the system of equations -3 x- 8y=19 4x+9y=-22

**physics**

crate weighs 823 N rests on plank that makes a 25 degree angle with the ground. Find components of crate's weight parallel and perpendicular to the plank

**Math**

1. -3/4*-(1 5/6)*(-7/4)= 2. -3/4*(-1 5/6)*7/4= 3. -3/4*(-1 5/6)*(-7/4)*(-2 3/8)= 4. 3/4*(- 5/6)*7/4*(-2 3/8)= 5. 3/4*1 5/6*7/4*(-2 3/8)=

**Math**

Info Sean is buying a new DVD player for 315. the store offers him an interest-free payment plan that allows him to pay in monthly installments of $25. Ques. Use n to stand for number of payments and a for the amount still owed. Write an equation for calculating a for any valu...

**Human services**

what are the pros and cons of placing children of color in a causian home?

**chemistry**

consider the following reaction: Mg(s)+ 2HCl(aq) --> MgCl2 (aq)+H2 (g) What minimum amount of 1.75 M HCl is necessary to produce 27.5 L of H2 at STP?

**Economics**

Quality Adjusted Life Years evaluates interventions in _____ rather than _____. a. dollars; years b. utility; dollars c. years; dollars d. dollars; utility

**Chemistry**

Ammonium carbonate decomposes upon heating according to the following balanced equation: (NH4)2CO3(s)-->2 NH3(g)+CO2(g)+H2O(g) Calculate the total volume of gas produced at 25 C and 1.07atm by the complete decomposition of 11.86 g of ammonium carbonate.

**Chemistry**

Ammonium carbonate decomposes upon heating according to the following balanced equation: (NH4)2CO3(s)-->2 NH3(g)+CO2(g)+H2O(g) Calculate the total volume of gas produced at 25 C and 1.07atm by the complete decomposition of 11.86 g of ammonium carbonate.

**Chemistry**

oh i think you have to convert the mm Hg to atm first

**Chemistry**

dont you just multiply .038 times the total pressure?

**Chemistry**

okay yeah i got it. thanks its 736 mmhg