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September 16, 2014

Posts by hannah


Total # Posts: 2,850

physics7
A 81.0-kg (179 lb) boxer has his first match in the Canal Zone (g = 9.782 m/s2) and his second match at the North Pole (g = 9.832 m/s2). (a) What is his mass in the Canal Zone? (b) What is his weight in the Canal Zone? (c) What is his mass at the North Pole? (d) What is his ...
December 11, 2011

physics6
A 64-kg boy and a 42-kg girl use an elastic rope while engaged in a tug-of-war on an icy frictionless surface. If the acceleration of the girl toward the boy is 3.5 m/s2, determine the magnitude of the acceleration of the boy toward the girl.
December 11, 2011

physics5
A race car has a mass of 707 kg. It starts from rest and travels 40 m in 4.0 s. The car is uniformly accelerated during the entire time. What net force is applied to it?
December 11, 2011

physics4
After a day of testing race cars, you decide to take your own 1540-kg car onto the test track. While moving down the track at 12 m/s, you suddenly accelerate to 27 m/s in 9 s. What is the average net force that you have applied to the car during the 9-s interval?
December 11, 2011

physics3
when a karate strike hits wooden blocks, the hand undergoes an acceleration of -6500 m/s2. Medical data indicates the mass of the forearm and hand to be about 0.7 kg. What is the force exerted on the hand by the blocks?
December 11, 2011

physics2
A 873 kg (1930 lb) dragster completed the 402.0 m (0.2498 mile) run in 4.950 s. If the car has constant acceleration, what would be its acceleration and final velocity?
December 11, 2011

physics
A 880-kg (1945 lb) dragster, starting from rest, attains a speed of 27.3 m/s (61.0 mph) in 0.60 s. (a) Find the average acceleration of the dragster during this time interval? (b) What is the size of the average force on the dragster during this time interval? (c) Assume the ...
December 11, 2011

us history
what do you think were the 15 most important events in us history between the founding of jamestown(1600's) and the end of the great depression (1930's)???
December 9, 2011

english
"big and solid as twelve pounds of mashed potatoes in an eight-pound bag" is an example of what?
December 8, 2011

Physics
Thanks but that just made me more confused.
December 7, 2011

Physics
The space shuttle has a weight 2.00 x 10^7 N. The shuttle is accelerated upward at a rate of 5.50 m/s^2. What is the mass of the shuttle? What is the thrust (force) of the combined engines? What is the magnitude of the net force applied to the space shuttle?
December 7, 2011

psychology
the effects of mood and gender on proxemics
December 6, 2011

science
Earths mass is 6 x 10^24kg and its radius is 6.38 x 10^6m (6380 km ). Use the inverse-square law to show that in space-shuttle territory, 200 km above the earths surface the force of gravity on a shuttle is about 94% of that at the earths surface.
December 5, 2011

Chemistry
1) what mass of oxygen will react with 2.64g of magnesium? 2Mg + O2 -> MgO I was going to do 2.64g * (1/2) from the equation but im not sure. Do I have to add a 2 in front of the MgO? 2) How many moles of sodium ions are present in 2.50 L of 0.300 M Na3PO4? I know M=moles/L...
December 4, 2011

Chemistry
For #2 I got 55.41 from (.5184 * 106.9051) so 55.41 + 0.4816x = 107.87 -55.41 -55.41 then divide by 0.4816 The answer is 108.91amu but I did not get this.
December 4, 2011

Chemistry
1) How many miles are covered in a 15km race? (1 mile=5280, 12 in=1 ft, 1in=2.54cm) I know that I have to convert but I do not know where to start. 2) Silver (107.87amu) has two naturally occuring isotopes. In a typical sample, 51.84%of silver exists as Ag-107 (106.9051 amu). ...
December 4, 2011

Chemistry
oh i see thank you!!!
December 4, 2011

Chemistry
I know the answer for protons is 45 and electrons 50 but i do not understand where that came from
December 4, 2011

Chemistry
1)How many protons and electrons are in a sulfate ion SO4^2- ? I know the answer is 48 protons and 50 electrons but i do not know how to get this from the ion. 2) What is the charge on a sulfide ion? The answer is -2 but im not sure why. Is sulfide always -2?
December 4, 2011

Chemistry(Please help)
Disregard
December 4, 2011

Chemistry(Please help)
1)How many protons and electrons are in a sulfate ion SO4^2- ? I know the answer is 48 protons and 50 electrons but i do not know how to get this from the ion. 2) What is the charge on a sulfide ion? The answer is -2 but im not sure why. Is sulfide always -2?
December 4, 2011

Physics
Well I know density is equal to mass/volume. So I guess find both! I know that doesn't really help at all (I'm taking physics too so I understand) but maybe going back to simplicity can help! Sorry!
December 1, 2011

us history
What was Scott Joplin most known for duirng the 1920's? please do not just give me a url to a site with his biography because i have already looked at many! I am trying to narrow my answer down to 3 sentences. thanks!
December 1, 2011

5TH GRADE MATH
the rule is subtract 8. I'm not sure if thats what you're asking or not but thats my answer! Hope it helped:D
November 30, 2011

Animal Science
I need a statistic of how many dogs and cats are currently in a foster home in the us. Does anyone know a website that has this credible statistic? thanks
November 30, 2011

math
how would i find the area of the parallelogram if the area of each right triangle region is 7 1/2 square inches
November 29, 2011

Algebra (direct variation)
the value of y varies directly with x, and y=-2 when x=-4 Find y when x=8 -2=k(-4)
November 28, 2011

Math
for the point deterime all six trigonometric ratios and the value of the principal angle and the related acute angle P( -3,0)
November 26, 2011

math
a store has a total of 108 full-time staff and part time staff. There are three times as many full-time staff as part time staff. How many of the staff are in each category?
November 24, 2011

Chemistry(Please help)
Nitrogen monoxide + Hydrogen --> nitrogen + water I need to balance this equation but I do not know how. NO + H --> N + H2O 2NO + 2H --> 2N Would this be correct? Thank you!!
November 23, 2011

history
what offically started and ended WWI? and what made the us enter the war?
November 23, 2011

chemistry
sulfur dioxide (g) + oxygen (g) sulfur trioxide (g) SO2 + O = SO3 Is this correct for the balanced equation?
November 20, 2011

chemistry(Urgent Please help)
A student is asked to standardize a solution of barium hydroxide. He weighs out 0.945 g potassium hydrogen phthalate (KHC8H4O4, treat this as a monoprotic acid). It requires 33.9 mL of barium hydroxide to reach the endpoint. A. What is the molarity of the barium hydroxide ...
November 20, 2011

Chemistry
A 8.71 g sample of an aqueous solution of hydroiodic acid contains an unknown amount of the acid. If 25.0 mL of 0.388 M barium hydroxide are required to neutralize the hydroiodic acid, what is the percent by weight of hydroiodic acid in the mixture? I understand how to solve ...
November 20, 2011

speech
I am doing a persuasive speech on why you should foster a dog or cat. but I am not sure what my three main points should be. do you guys have any idea?
November 19, 2011

Chemistry
I am doing similar homeowrk and I was wondering how you calculate the ph after the equivalence point?
November 17, 2011

History
diary + the poems he wrote
November 17, 2011

History
so was his main contribution when he fuoght with the french or the diary that he kept that showed what the war was like?
November 17, 2011

History
What was Alan Seeger do that made an impact during WWI?
November 17, 2011

Chemistry
For a lab experiment we have to draw the lewis structures of hydrides. 1) Carbon It asks for the formula of hydride. Total # of valence electrons and the lewis structure. Total electrons would be four. I am not sure what the formula would be or how to find that and and the ...
November 16, 2011

Chemistry
The compound butane, has two structures. They have the same molecular formula but different arrangements of bonds in their structures. As a result, they can have different chemical and physical properties. Draw the lewis structures of all the isomers of pentane, C5H12. I am ...
November 16, 2011

geometry
why do elephants have pointy tails
November 14, 2011

Math
Your friend states that your mortgage is "an annuity where you are the bank."What does she mean?
November 10, 2011

Chemistry
Is the structure for chlorous acid H O Cl O or H Cl O ? O I was thinking that both could be correct but I am not 100% sure.
November 9, 2011

Chemistry
Is the structure for chlorous acid H O Cl O or H Cl O ? O I was thinking that both could be correct but I am not 100% sure.
November 9, 2011

physics
Two dogs pull on a toy. One pulls with a force of 10 N, the other with a force of 15 N. (a) In what relative directions can the dogs act to give the toy the smallest acceleration?
November 8, 2011

english
where in the book The Importance of Being Earnest does the author make fun of the victorian value of Social Responsibility?
November 7, 2011

Chemistry
We have to conduct a lab experiment for a photochemical reaction. We will be using a redand violet film and filter paper labeled 40W and 60W. On each piece of paper we will add 1 drop of NaCl and AgNO3 and then let it sit under a lamp to see what happens. At the end we will ...
November 2, 2011

Chemistry
ok thank you I apprieciate all of your help!!
November 2, 2011

Chemistry
In the cchemistry lab we conducted an experiment called atomic spectroscopy. We had to find the color, energy, wavelength, and 1/lamda for Hydrogen, neon, and mercury. For hydrogen: red 1.90ev 650nm 1.54e^-3 red 2.02ev 610nm 1.64e^-3 green 2.30ev 545nm 1.83e^-3 for neon: green...
November 2, 2011

Chemistry
1) What is the charge on the ion that Selenium forms in an ionic compound? I am not sure about this. 2) What noble gas is isoelectronic with this ion. I was thinking Krypton because it is a noble gas and it is the closest to Selenium but I am not sure. 3) What other ions are ...
November 2, 2011

Chemistry
ok where do you get those numbers from?
November 2, 2011

Chemistry
for chose 5 Ca is next to K and above Sr so wouldnt Sr be greater?
November 2, 2011

Chemistry
1) A Cobalt (II) ion has the electron configuration ____? and is ____? The answer choices were: [Ar] 3d5 4s2 diamagnetic [Ar] 3d7 paramagnetic [Ar] 3d5 4s2 para [Ar] 3d7 dia None of these I chose [Ar] 3d5 4s2 diamagnetic 2) Choose the corect statement concerning ionization ...
November 2, 2011

Chemistry
Thank you for your help!!!
November 1, 2011

Chemistry
1) What is the atomic # for selenium? 34 2) Write the full electron configuration for selenium following the (n+l) rule? I am not sure what is meant by n+l 3) write the electron configuration, grouping electrons by their "n" values. [Ar]3d10 4s2 4p4 Are these correct...
November 1, 2011

Chemistry(Please check)
Thank you!
November 1, 2011

Chemistry(Please check)
1)For an atom of carbon how many valence electrons are "s" electrons? 2 2) How many are "p" electrons? 4 3)How many (total) electrons in carbon are paired? 2 4) How many are unpaired? 1 Are these correct.
November 1, 2011

chemistry
Based on the nl designation and max # of electrons above, write the electron configuration for carbon. 1s2 2s2 2p2 or [He]2s2 2p2 How many electrons are in the first shell n=1? These are the core electrons for carbon. I think two are in the first shell How many valence ...
November 1, 2011

chemistry
the question then says to expand the above values in the table for all the l values of n=4. Are more possible for n=5? I am not sure what they mean by expand it but I think that there are more values for n=5.
November 1, 2011

chemistry
ok so for n=3 and l value 0 it would be the the nl would be 3s and max electrons would be 18?
November 1, 2011

chemistry
o ok. In my textbook it shows a chart with electron shells and it has the maximum electrons possible for nth shell (2n^2). What does this mean?
November 1, 2011

chemistry
So for the following: 1)n=2 2) l=0 3) l letter= s 4) nl designation= 2s Are numbers 2 and 3 correct?
November 1, 2011

chemistry
o ok i think i understand and what would the maximum number of electrons be?
November 1, 2011

chemistry
write the corresponding subshell leters for the combinations given. Fill in the possible number of electrons for these subshells. 1) n=1 2) l value=0 3) l letter? 4) "nl"Designation 5) Maxium # of electrons the table shows n values of 1, 2,2,3,3,4 with l values of 0,...
November 1, 2011

Chemistry
In the cchemistry lab we conducted an experiment called atomic spectroscopy. We had to find the color, energy, wavelength, and 1/lamda for Hydrogen, neon, and mercury. For hydrogen: red 1.90ev 650nm 1.54e^-3 red 2.02ev 610nm 1.64e^-3 green 2.30ev 545nm 1.83e^-3 for neon: green...
November 1, 2011

Chemistry
In the cchemistry lab we conducted an experiment called atomic spectroscopy. We had to find the color, energy, wavelength, and 1/lamda for Hydrogen, neon, and mercury. For hydrogen: red 1.90ev 650nm 1.54e^-3 red 2.02ev 610nm 1.64e^-3 green 2.30ev 545nm 1.83e^-3 for neon: ...
November 1, 2011

Chemistry
on the x axis was 1/wavelength (nm-1) and the y axis was energy(ev). The line for both graphs of neon and hydrogen was positive. So would I pick two points on the graph to find the slope and then do h=slope/c?
October 31, 2011

Chemistry
In the cchemistry lab we conducted an experiment called atomic spectroscopy. We had to find the color, energy, wavelength, and 1/lamda for Hydrogen, neon, and mercury. For hydrogen: red 1.90ev 650nm 1.54e^-3 red 2.02ev 610nm 1.64e^-3 green 2.30ev 545nm 1.83e^-3 for neon: green...
October 31, 2011

Chemistry
Consider the last electron in B: Values for n,l,and ml of 2,0,0 cannot be used. Why not? so is this the same answer as lithium. The ground stat cant have l=2 since it has no p electrons? Are values of 3,0, 0 allowed? Why or why not? I would say no for the same reason. Are ...
October 31, 2011

Chemistry
What are the n,l,ml,and ms values for the last electron in Be?
October 30, 2011

chemistry
Consider the last electron in Li: Values n,l,ml,and ms of 1,1,0, +1/2 are not allowable. Why not. I do not understand this question. I am not sure what the values for the last electron would be.
October 30, 2011

Chemistry
Electron Configuration: What numerical values of l are possible for n=4. 1,3,5,7 what ae their corresponding letters. s,p,d,f Are these correct?
October 30, 2011

Chemistry
o ok thank you!!
October 30, 2011

Chemistry
Thank you and sorry. Sometimes it does not show up on my computer when someone answers.
October 30, 2011

Chemistry
Write the n, l, ml, and ms values for the first two elements, H and He. H: n=1 l=0 ml=0 ms=+1/2 He: n=1 l=0 ml=0 ms=+1/2 for the first electron for the second: n=1 l=0 ml=0 ms=-1/2 Are these correct?
October 30, 2011

Chemistry(Please check)
Write the n, l, ml, and ms values for the first two elements, H and He. H: n=1 l=0 ml=0 ms=+1/2 He: n=1 l=0 ml=0 ms=+1/2 for the first electron for the second: n=1 l=0 ml=0 ms=-1/2 Are these correct?
October 30, 2011

Chemistry
ok thank you!!
October 28, 2011

Chemistry
For each l value indicate the ml values allowable? l=1 ml=+1, 0, -1 l=2 ml=+2,+1,0,-1,-2 l=3 ml= everything from +3 to -3 l-4 ml= everything from +4 to -4 Are these correct? What are the ms values allowable? These I am not sure about. Is it the number of orbitals?
October 28, 2011

Chemistry
Quantum numbers: What are the n values that are allowed? I put 1,2,3,4, etc. For the first four of these, indicate the l values allowed. n=1 l = 0 n=2 l = 0,1 n=3 l = 0,1,2 n=4 l = 0,1,2,3 Are these correct?
October 28, 2011

derivatives
How do you find the derivative of (6 csc x)/x?
October 28, 2011

derivatives
I know. I just realized that I messed up what goes where when I was doing it myself. My problem is applying it to other problems, esp when i also have to use the quotient or product rule.
October 27, 2011

derivatives
Thanks. My teacher told us we need to use the chain rule in these problems, and i'm having trouble figuring out when and where to use it.
October 27, 2011

derivatives
how do u find the derivative of (csc x)^7 -cos 4x???
October 27, 2011

Calc
to find an arcsin you would just have to memorize the unit circle right? so arccos of -sqrt3/2 is 5pi/6?
October 26, 2011

Calc
oops mixed up 2 questionss haha
October 26, 2011

Calc
How do you do the derivative of an inverse trig function? arcsin (sqrt2/2)??
October 26, 2011

Chemistry
yes thank you i understand the parts for moles of KHP and NaOH. So the mw of KHP was given to me which was 204.44g/mol so for moles of KHP i did 1/204.44 and got 0.004 and then for NaOH i got 0.004 as well. Then for the concentration of NaOH would i do 0.004/0.0145 and 0.004/0...
October 26, 2011

Chemistry
For a chemistry lab the experiment was to carry out an acid-base titration to determine the exact concentration of a sodium hydroxide solution. Two trials were completed and the data collected was: mass of weighing paper, mass of weighing paper + KHP, mass of KHP, initial ...
October 26, 2011

Chemistry(Please help, thank you!!)
Thank you!!
October 25, 2011

Chemistry(Please help, thank you!!)
ok i do not understand at all but thank you for your help.
October 25, 2011

Chemistry(Please help, thank you!!)
SO would it be 27.80 / 10.00?
October 25, 2011

Chemistry(Please help, thank you!!)
Determine the concentration of a NaOH solution if 27.80mL of NaOH is required to neutralize 10.00mL of a 1.00 M H2SO4 solution. (Hint:Review monoprotic vs. diprotic acids.) would I do (27.80)(10)? Thank you for your help!!
October 25, 2011

Chemistry(Please help, thank you!)
ok so for mole of kHP it would be 1/204.44 = 0.00489 g/mol? The volume of NaOH for trial 1 was 14.50 mL and for trial 2 it was 9.90mL. So would it be 39.998 which is molecular mass of NaOH divided by the volume?
October 24, 2011

Chemistry(Please help, thank you!)
For a chemistry lab the experiment was to carry out an acid-base titration to determine the exact concentration of a sodium hydroxide solution. Two trials were completed and the data collected was: mass of weighing paper, mass of weighing paper + KHP, mass of KHP, initial ...
October 24, 2011

Geology
For my final I am to write a paper discussing the following : Select some product produced in your city or state that is made from earth, mineral, or energy resources. One example would be the tar paper used as a building material. (Do not use this example). Prepare a 700- to ...
October 23, 2011

Chemistry
Thank You!!!
October 23, 2011

Chemistry
A concept map was to be created on acids and bases. The concept terms that were given to use were: aqueous solution,bases,acids,ions,weak bases, strong bases, strong acids, weak acids,dissociation, weak electrolyte, strong electrolyte,reaction,salt, neutralization, hydronium ...
October 23, 2011

Chemistry(Please help!!)
For a chemistry lab the experiment was to carry out an acid-base titration to determine the exact concentration of a sodium hydroxide solution. Two trials were completed and the data collected was: mass of weighing paper, mass of weighing paper + KHP, mass of KHP, initial ...
October 23, 2011

Science- physics
Thank you so much! My teacher has NO idea how to teach us anything! I really appreciate your help! Thanks <3
October 23, 2011

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