Christina

This page lists questions and answers that were posted by visitors named Christina.

Questions

The following questions were asked by visitors named Christina.

A particle has a velocity of 18m/s at a certain time and 2.4s later is velocity is 30m/s in the opposite direction. What are the magnitude and direction of the particle's acceleration during the 2.4s interval? I udes a=change in velocity /change in time a...

What is litum paper made of? If you cant find anything can you try to find some websites for me? THANKS A LOT!! 8-] litmus paper traditionally is a good grade (cotton) paper, with an extract of vegetable dye from the Litmus plant. http://www.botanical.com...

Hey people! i really need some help here. im doing an assignment and i need info (sites) i need to no umm the average humidity, UV index, daylight, wind, storms, cyclones and any other things. please. oh, and i need it on townsville. so if anyone could fi...

I need to solve this problem. A teacher can grade 25 papers in 4 hours. How many papers can he grade in 6 hours?

Can anyone please read over my assignment and let me know if there are any grammar or spelling errors? CheckPoint: Modern Challenges in Immigration o Should United States government policy favor certain kinds of immigrants? o Should [citizenship] preferen...

The MorTex Company assembles garments entirely by hand even though a textile machine exists which can assemble garments faster than a human can. Workers cost $50 per day, and each additional laborer can produce 200 more units per day (the same for each ad...

Whats the difference between a scientific theory and a regular theory? A theory may be about anything but a scientific theory is designed to explain some scientific principle. Why people shop at a certain store might be an ordinary theory but why AgCl is...

3x+2y=6 -6x-3y=-6

A CD rotates at 500 (revolutions per minute) while the last song is playing, and then spins down to zero angular speed in 2.60 seconds with constant angular acceleration. The magnitude of the angular acceleration of the CD, as it spins to a stop is 20.1 r...

Tidal Energy. If we model 2 blades as thin uniform steel bars 15.0m long and .25m in diameter, at what rate (radians/second and revolutions per minute) must they spin for a turbine to store 10^6 J of energy? Keep in mind that the density of steel is 7800k...

To strengthen his arm and chest muscles, an 83.0 kg athlete 2.00 m tall is doing a series of push-ups. His center of mass is 1.15 m from the bottom of his feet, and the centers of his palms are 30.0 cm from the top of his head. Find the force that the flo...

what is the indirect object in this sentence "Chandler gave her the magazine"

A small block on a frictionless horizontal surface has a mass of 2.50×10−2 Kg. It is attached to a massless cord passing through a hole in the surface. The block is originally revolving at a distance of 0.300 m from the hole with an angular speed of 1.75...

The outstretched hands and arms of a figure skater preparing for a spin can be considered a slender rod pivoting about an axis through its center. When the skater's hands and arms are brought in and wrapped around his body to execute the spin, the hands a...

The Achilles tendon, which connects the calf muscles to the heel, is the thickest and strongest tendon in the body. In extreme activities, such as sprinting, it can be subjected to forces as high as 13.0 times a person's weight. According to one set of ex...

In the Grimms' fairy tale Rapunzel, she lets down her golden hair to a length of 20.0 yards (we'll use 20.0 m, which is not much different) so that the prince can climb up to her room. Human hair has a Young's modulus of about 490 MPa, and we can assume t...

At the time this problem was written, the price of gold was $427 per ounce, while that of platinum was $866 an ounce. The "ounce" in this case is the troy ounce, which is equal to 31.1035 g. The density of gold is 19.3 g/cm^3 and that of platinum is 21.4...

Europa, a satellite of Jupiter, appears to have an ocean beneath its icy surface. Proposals have been made to send a robotic submarine to Europa to see if there might be life there. There is no atmosphere on Europa, and we shall assume that the surface ic...

From a height of 35.0 m, a 1.25 kg bird dives (from rest) into a small fish tank containing 50.0 kg of water. What is the maximum rise in temperature of the water if the bird gives it all of its mechanical energy? (delta)T= ?? degrees C

Oxygen (O2) has a molar mass of 32.0 g/mol [.032kg/mol]. What is the root-mean-square speed of an oxygen molecule at a temperature of 310 K? Vrms=492 m/s What is its average translational kinetic energy at that speed? Kav= ?? J I am having problems with t...

You decide to use your body as a Carnot heat engine. The operating gas is in a tube with one end in your mouth (where the temperature is 37.0 C) and the other end at the surface of your skin, at 30.0 C. What is the maximum efficiency of such a heat engine...

The radius of a certain planet is 6.04x10^7 meters, and its mass is 5.19x10^26 kg. Find the density of this planet. (The volume of a sphere is given by (4/3)(pie)(r^3). Answer in units of grams/cm^3

The foot of a ladder is placed 6 feet from a wall. If the top of the ladder is 8 feet up on the wall, how long is the ladder?

How would I combine ions? like how would Sr be combined as a positve or negative ion? I DON'T GET IT!

Which of the following quadrilaterals must have diagonals that bisect each other? Rectangle Parallelogram Rhombus Isosceles Trapezoid

Given Information: Light of wavelength 631 nm passes through a diffraction grating having 485 lines/mm. Part A: What is the total number of bright spots (indicating complete constructive interference) that will occur on a large distant screen? *Answer: 7...

A 22.8 kg turntable with a radius of 47 cm is covered with a uniform layer of dry ice that has a mass of 4.08 kg. The angular speed of the turntable and dry ice is initially 0.52 rad/s, but it increases as the dry ice evaporates. What is the angular speed...

QUESTION 1: Calculate the maximum increase in photon wavelength that can occur during Compton scattering. = ??? pm QUESTION 2: What is the energy (in electron volts) of the smallest-energy x-ray photon for which Compton scattering could result in doubling...

Background: A monochromatic laser is exciting hydrogen atoms from the n=2 to state to the n=5 state. Question: What is the shortest wavelength observed? -I believe that it will be from n=5 to n=4, but I am not sure what equation to use or how to use the n...

In this function, f(x)= [2/(x-3)]+1: I know it is a rational function and the graph moves 1 unit up and 3 units right. I also see that the 2 makes the function move closer, but I don't understand why it does that in mathematical terms.

i have to mark on a map of ancient greece, where thera and thrace are can anyone help me or give me a site that would have good maps? thanks so much

what does this mean in english? and would it be true or false? sorry this is the only one i do not understand. unos temas comunes para el noticiero son como preparar platos exquisitos, como viven las estrellas de cine y como aprender a pintar.

I need help factoring 64b^2-(q+r)^2

I am thinking of a number.It is a multiple of 3 but not 6.It is greater than 25^2 but less than 30^2.The units digit is a perfect square and the sum of the other two digits is the square root of 81. What is my number? A three-dimensional model of a city h...

what number is 24% of 95. Sorry but i don't understand how to get numbers using percents. another problem im stuck with is what percent of 90 is 60

Hi can anybody help me with some websites leading to interesting facts about mt everest. For example its history,the culture,first women to climb.etc. Thank you.

Okay i stuck on a problem can anyone help? There are 14 people total.7 are girls a day.Everyone has to work for 7 days also everyone has to have 2 days off.So how many days does a girl work a week?

IF P(A)=40%,P(A OR B)=60%,P(A AND B)=30% WHAT IS P(B)

If P(a)=1/5, P(A and B)= 1/8, what is P(b/a) i don't get it is it the same way as finding p or b or is it something entirely different and how do you find it

how do you do permutations??? distinguishable ex. Sweetwater would you put the total number of the letters on top and then put what is repeated on bottom???

How does binomial monenclature relate to Genus and species? Also, what is the proper form for the scientific name of an organism?

If L is the lenth of an arc, r is the radius and degree is the angle subtended by the arc, find the angle when l=9.4cm r=4.5cm

I'm really stuck with this question can someone please help me. A bus is scheduled to stop at a certain bus stop every 45 minutes. At the end of the day, buses still stop after every 45 minutes, but because delays often occur earlier in the day, the bus i...

HELP PLEASE!! Show that Euler’s formula holds for the polyhedra called a right pentagonal prism?

I'm curious about this question can someone please help me out. what is the unit measure of a button in mg?

How would I summarize this news article

Of what value is knowledge of density to a chemist?

What is Scientific Principle?

If you were to expend 10 Joules of work to push a 1-coulomb charge against an electric field, what would be its voltage with respect to its voltage in its starting position? When released, what will be its kinetic energy if it flies past its starting posi...

how do you turn a decimal to fractions and percents? like .6 or .001 also how do you turn 2.85% into fraction and decimal?

Some drain cleaners contain a mixture of sodium hydroxide and aluminum which reacts with water as follows: 2Al(s)+2 NaOH(aq)+6H2O(l)->2Na[Al(OH)4](aq)+3H2(g) What mass of hydrogen gas can be produced when 5g Al reacts with sufficient NaOH and H2O) accordi...

Chlorine gas may be easily prepared in the lab according to the reaction: 2KMnO4(s)+ 16HCl(aq)-> 2 MnCl2(aq)+5Cl2(g)+ 8H2O(l)+ 2KCl(aq) What mass of HCl is needed to prepare 1 mole of Cl2 gas?

What is the ionic and net ionic equation for Na2CO3 + 2 HNO3 -> 2 NaNO3 + H2O + CO2 (g) This is what i have so far... Na2(aq)+CO3+H+NO3 -> Na+ NO3+ H2O(l)+CO2(g)... i don't know what to do!!!

What is the ionic and net ionic equation? Ca(HO)2(aq)+ Na2CO3(aq)-> CaCO3 -> (s)+ 2NaOH (aq) I don't understand why there are two arrows? This is what i have so far... Ca+2OH+Na2(aq)+CO3(aq)...

Another ionic and net ionic equation that i am having trouble with!!! I need the ionic and net ionic equation KOH+ HBr -> KBr+ H2O

How many liters of hydrogen at STP can be produced by the reaction of 4.15 g of zinc with hydrochloric acid: Zn + 2HCl -> ZnCl2 + H2

A 0.35 mol sample of an ideal gas is held in a vessel at 0.C and a pressure of 785 torr. What is the volume of the vessel? (R=62.36L x torr/mol x K)

Are the melting point and freezing point of a substance represented by the same number?

On a melting curve, the heat energy represented by the horizontal portion of the curve is called what?

Calculate the amount of heat (in calories) required to raise the temperature of 200g of water from 20C to 50C. The specific heat of water is 1.00 cal/g. I have done other spacific heat problems but on this one i don't know how to start...

True or false? Hydrogen bonds between water molecules are comparable in strength to hydrogen-carbon covalent bonds?

Name the following compound? FeCl3 x 6H2O

Complete and balance the following equation? __P4O6+__H2O -> ___________

When one mole of LiBr is dissolved in 1 kg of H2O, the concentration of the Br- is 1. 0.5 molal 2. 0.5 molar 3. 1.0 molal 4. 1.0 molar

Which of the following would have the lowest vapor pressure? A. 0.8 m C6H12O6 B. 0.10 m C6H12O6 C. 0.05 m C6H12O6 D. 0.15 m C6H12O6 I think it is D... is that correct? Which of the following would have the lowest boiling point? A. 0.8 m C6H12O6 B. 0.10 m...

True and False... 1. A thermodynamically favorable reaction also proceeds spontaneously. I think that it is false? 2. Doubling the concentration of a reactant always causes the reaction rate to double. 3. a reaction that has a large activation energy in t...

an exothermic reaction involves a. breaking weak bonds to form weak bonds. b. breaking weaker bonds to form stronger bonds c. breaking srtong bonds to form strong bonds. d. breaking stronger bonds to form weaker bonds. I think that it is a.

Which of the following has the greatest entropy? A.1 mole NaCl (g) at 25C B.1 mole NaCl (g) at 50C C.1 mole NaCl (l) at 50C D.1 mole NaCl (s) at 100C I know that gases have the highest entropy and the higher the temperature the higher the entropy...so i a...

Using G (measure of free energy) to determine wether the reaction 4Fe(s)+3O2(g)-> 2Fe2O3(s) is spontaneous at 25C, given that H=.393kcal and S=-0.13 kcal/(mol*K). Is the reaction more or less spontaneous at 1000C assuming that H and S remain constant with...

can you give me some facts and info bout how plate tectonics accounts for the features and processes that geoscientists observe in the earth -thank you

Hurricane Katrina dropped about four-teen inches of rain over a 48 hour period. How much rain is this in one hour ?

you can produce a sound by plucking a string or blowing in a pipe. how is this alike? how is this different?

the solubility product expression for BiS3 is Ksp= a.[Bi2^3][S3^2-]. b. [Bi^3+][S^2-]. c. [Bi^3+]^2 [S^2-]^3 d. none of these

The mineral CaF2 has a solubility of 2.1 x 10^-4 M. What is the Ksp of CaF2? a. 1.85x10^-11 b. 9.3x10^-12 c. 3.7x10^-11 d. 8.8x10^-3

How have cultural differences in Europe caused conflict?

Sally's collection of quarters and dimes contains $32.85. There are 171 coins in all. How many quarters and dimes are in Sally's collection? Can you show me the two equations you got and explain -Thanks

If a single bacteria divides in half every 20 min. how many would you have after 42 hours?

A boulder has 300 J of potential energy sitting on the edge of a cliff. What is the boulder's kinetic energy as it hits the ground?

Another question :) At the top of its drop hill, a 1,000 kg roller coaster has 200,000 J of total energy. If the top of the next hill is 13 meters, what is the kinetic energy of the roller coaster on this hill? Thanks

How does a doctor diagnose the flu? What tests are performed? What samples need to be taken?

Calculate the specific heat of a metallic element if 314 joules of energy are needed to raise a 50.0 g sample from 25 to 50 degress C ? :)

what's a sentence for glisten and tomb

i have to write a three sentences about my family, using irregular verbs and i do not know what to write or what irregular verbs are

Why is the discussion of the problem of evil important to augustine's ethic?

Describe Hobbes' account of man's action and how it fits into his ethical system.

What is insulating fiberglass?

What is sodium perborate bleach?

The Cu2+ ion can be separated from Ag+, Ca2+, and K+ in aqueous solution by 1. precipitation of Cu2+ as Cu(OH)2(s) with 6 M NaOH(aq). 2. precipitation of Ag+, Ca2+, and K+ as the carbonates. 3. None of these procedures will separate Cu2+ from the other io...

Is this a good sentence using the words: affliction: the cause of persistent pain or distress I was afflicted by grief after my cousins death. Digress: to turn aside especially from the main subject of attention or course of argument While discussing the...

Is this a good sentence using the words: Procure: to get possession of; achieve If you study hard you will procure good grades. Beguile: to lead by deception; divert The dog beguiled the thief's attention away from the cowering people towards him. Truce:...

Whats an example of product? Definition: the substances produced in a chemical reaction

What are some examples of precipitate? Definition: an insoluble solid formed in a liquid solution as a result of some chemical reactions

What would happen to the color of a dilute solution containing FeCL4 if you added concentrated HCl?

Explain why a heavy rainfall on a fruit orchard in the spring might result in a poor fruit yeild in the fall.

can i get answers to my homework ?

200. g of a nonelectrolyte is dissolved in 1.00 kg of water. the boiling point of the solution is then measured to be 101.5 degrees C. What is the molar mass of the compound? The Kb for water is 0.51 degrees Celsius/m

Calculate the boiling point elevation of a solution made from 15.0 g of a nonelectrolyte solute and 250.0 g of water. the molar mass of the solute is 50.0 g and Kb = 0.51 degrees C/m

On January 1st a savings account showed a balance of $280. How much interest will be earned by the end of the year at an annual rate of 5 1/4?

Ngata Corp. issued 12-year bonds 2 years ago at a coupon rate of 8.4 percent. The bonds make semiannual payments. If these bonds currently sell for 105 percent of par value, the YTM is ? percent

Answers

The following answers were posted by visitors named Christina.

Yes. An elements number of neutrons and electrons can change, but its number of protons will not vary. Therefore, the atoms of the same element do have the same number of protons.

How do I determine the volume of the blade so I can find the mass? I'm not quite sure what shape the figure actually is...

M=7800*[(1/4)*PI*(.25)^2*15] KE=(1/2[(1/3)M(15)2]w^2=10^6 KE=2.15... x2 (for the two blades) KE=4.31 would that be in radians or revolutions?

I can't seem to find where I've gone wrong... Volume=(1/4)PI(.25)^2*15=.736... Mass= V*7800= 5743.2... I=(1/3)M*15^2=430741.8... 10^6=(1/2)Iw^2 w=sqrt(4.64...) w=2.15... w*2[for the 2 blades]=4.309... I tried the above value and was incorrect.

I can't seem to find where I've gone wrong... Volume=(1/4)PI(.25)^2*15=.736... Mass= V*7800= 5743.2... I=(1/3)M*15^2=430741.8... 10^6=(1/2)Iw^2 w=sqrt(4.64...) w=2.15... w*2[for the 2 blades]=4.309... I tried the above value and was incorrect.

I'm on the change in KE part and this is what I get: KEf=(1/2)(2.5*10^-2)(.150*7)^2 =.01378125 KEi=(1/2)(2.5*10^-2)(.300*1.75)^2 =.0034453125 I'm not quite sure what to do with these two numbers... I subtracted KEi from KEf, but was told I had "rounding e...

I'm still getting A wrong.... F=(1.474*10^9)(7.81*10^-5)/(.25) *.0125 =5755.95 Pa

I did that and I'm still getting a wrong answer... Is it possible that my calculations are wrong somewhere else?? I'm at a loss...

I'm not getting the correct answer.. this is my work: Q=214.374/4.18 =51.286 51.286=(50)(10^3)T T=.001 Do I need to convert the T to something else? It says to have it in C, which I think it's already in...

Here is what I've done, hopefully you can identify where I've gone wrong.. =(1/2)(.032)(492)^2 =3873J

ok, that makes much more sense... then i'm assuming that:n=2 for O2 and the m is .032 ???? M=n*m =2*.032 =.064 Then (1/2)(.064)(492)^2 =7746 ??????

I am beyond lost..I've never had any chemistry and our professor assumed that we had at least a basic knowledge...is there any way you could walk me thought this?

I can't figure out what to do after this problem : what mass of SO2 is produced from the reaction between 31.5 g of S8 and 8.65g of O2? I have figured out the balanced equation but do I pick one of the givens and solve it straight out?

Thanks :) It is 30 by 44 feet :)

Okay.. whats the Pythagorean theorem again?

Okay i think i got it. a^2 + b^2 = c^2 6^2 + 8^2 = c^2 36 + 64 = c^2 sqrt of 100 = sqrt of c^2 10ft = C Is that right?

Ooh wonderful! There is another problem similar to it...I am having trouble finding the # of fringes, but I think once I get help with that I can solve for the angle!!! GIVEN: Light of wavelength 585 nm falls on a slit 6.66×10−2 mm wide. Part A: On a very...

I have solved Question 1 (=8.5 pm), but am still struggling to answer Question 2! Any help would be beyond greatly appreciated!!

I have solved Question 1(=8.5 pm), but am still struggling to answer Question 2! Any help would be beyond greatly appreciated!!

thank you for replying, but i figured it out

look it up on google but i found it on klb science interactive excercises

thank you soo much

number one means for what do you use ipods? not how long. and conjugate usar. so it would be yo uso los ipods por.... etc. 2. it means for how many hours do you study for a math exam. it would be yo estudio por cinco horas para una examen de matematicas....

Thank you so much. The sites helped me a lot.

plug in the numbers for x and y into the multiple choice and see which one works ex. y=1 and x=-3 1=2(-3)-5 does that work ...no so try it on a different choice

so it would be division then i would have to cross multiply right??? by the way thank you...Alot!

Well you see bobpursley I have this four options.. 1. 1.14mg 2. 0.014mg 3. 140mg 4. 14mg But since Milligram is about the mass of one human hair, then I'm assuming a button is 140mg am I correct?

How would I summarize this Article "Lawyers war over job tax" Lawyers on both sides of the Jeff. County occupational tax case say they have a right to $17.5 million of job revenue being held in escrow and on Wednesday tok step to gain access to the money....

Thank You so much!, GK!

DrBob222... I really don't know where to begin.. One Mole of Cl2 gas is 70.9g I have done mass to mass conversions but the mole ini the problem is giving me trouble!!!

1 mol C2H2/26.036g C2H2 x 16 mol HCl/1 mol Cl2 x 64.1gCaC2/1 mol CaC2 My answer = 583.328g HCl?

oops.... wrong problem... answer.. 16 Mol HCl/1 Mol Cl2 x 36.458g HCl/1 Mol Cl2 = 583.328g HCl

The problem is i don't know how to do it....i don't know how to separate the ions that are solubale.....

785torr(V)= 0.35mol(62.36L)(273K) answer: 7.6 L is this correct? i am not sure that the R(62.36L) is what is supposed to be there.

Iron (III) chloride?

P4O6+6H20= 4H3PO3 ?

umm... i'm not sure. are you telling me that i will?

I worked in K.... so at either temp the reaction is not spontaneous? but it is more spontaneous at 1000C?

6y=8y-7 find the value of y?

Thank you guys. This was very helpful

I have to agree with all of you. I do not understand my text book at all. Im also like all of you, am getting good grades in all my other classes and even in my Psy 265 class but I'm carrying a C+ in this class. The teacher isn't any help either.

thank u so much miss sue sorry to bother u

yours was more easier to under stand

16 divided 4 can help u find the answer 160 divided because 61/4=4 and u just add a 0 so its 40

if the answer is negative it has no real # of solutions; if it is positive it has 2 real # of solutions; if its 0 it means 1

i got a 5x-2(7x+1)=14x 5x-14x-2=14x -9x-2=14x

4(9.75h-3)=150 39h-12=150 39h=138 39h/39=138/39 3.6 when rounded

NOO PROBLEM SOO MUCH :D

i think it is : 25c sqaured-5c-45c+9 25c squared-50c+9

thank you! i think the answer is 0.00612 is the delta t

3, because the 0 don't count, they would count if the number had a decimal point at the end, but it doesn't so 3.

8000 BC-600 CE I don't know

Make the ft into ins. (12 in. in a foot) and muilitpy length *width *height.

thank you, please help me.

Oh, okay. They all had a social hierarchy, and some sort of government. The main type of ecominic income was agriculture-i think-.

One quarter is 1/4 or .25 so * .25 * 6= ? Then do the same thing you did for A and there you go (:

to get different opinions.

Okay first you have to go from miles to ft then to iniches and then to cen? right? So you put what your trying to find on top. I'm not going to do this for you so tell me, how many feet are in a mile?

K cool. first step 3 miles * 5280 ft __________________ 1 ft 1 mile. Now muilitply top times top ( 3 times 5280) and then divide it by the answer at the bottom when u muiltply. (1 times 1)

Thank you!!!!!!!! I love <3 this site.

That's wrong Muilitpy 3* 5280

483000 in what units?

With different kind of maps

Or google translate!

tyrell because you must round it up because it is over 749 it rounds up.

what does it mean by institutions? How do I describe Legalism?

divide all the points given by two then graph them and connect the points. (:

1/33 percent of 600?

GOOOGLE. EASY question for google. com

aryans is an old english language?? and guptas was an ancient Indian empire

Notes, Feelings, Diary, Storys, Essays, Thoughts, Pictures.

why can't u google it?

I don't know, mabye it's a typo. Just ignore that word.

From 8000Bc- 600 AD This is talking about the fall of Rome and greece.

The answer should be 14. Substitute "6" for every "x" and solve.

Thank you so so much And I also posted another physics question down below if you don't mind helping me out?

Thanks for your help :)

Consider: 4 children - .5 x 4 = $2 1 man - 1 x 2 = $2 32 women - 32 x 3 = $96 total = $100

thank you, okay I wasn't' sure

yes but how could it be 937.50 minutes when you will pay 100 or 55 dollars either way for 1200 or 1000 minutes. It would need to be over those minutes.

what are the 5 parts of a sphere? in order please from left to right (lightest to darkest)

The y-intercept is correct, but -5400 would not be the slope of the line. Remember that slope represents the rate of change, specifically the change in y divided by the change in x. In this case, y is the value of the automobile and x is the year. If that...

Okay, so with the first part, 5(2y+1), you distribute the 5 to BOTH parts of what is inside the parentheses, so you have 5(2y) + 5(1). That gives you 10y + 5. Now, for the second part of the equation. When you have that negative in front of that parenthes...

Actually, I am Christina. Alex is my friend, we are working on our practice essays together. :) This is question 2, the other one is question one. Thanks for the help, though!

all you do is combine them.

Is the point (-3, -2) a solution of the intersection of the following set of quadratic equations: Y < - X ^ 2 X^2 + Y^2 < 16

the ideas didn't show up

Ok thanks, so do you just find the molar mass of those 8 grams of water to find moles?

.2M of NaOH(aq)