Sunday

April 26, 2015

April 26, 2015

Total # Posts: 693

**Physics**

Have 2 identical cars each 1000kg at a speed of 20m/s. The yellow car is stopped by car's brakes in 25m while green car is stopped by concrete barrier in 1.2m. Drivers have same mass(70kg) Driver of yellow car is stopped by seatbelt in 0.150 sec. Compare impulse they ...
*December 7, 2010*

**Chemistry**

1. State specifically how you would make a conclusive test for an iron (III) salt. 2. Which test for iron (II) ions is conclusive. 3. Suppose you have a solution containing both an iron (II) salt and an iron (III) salt. How would you proceed to identify both Fe2+ and Fe3+ in ...
*November 28, 2010*

**college algebra**

9 − 34 − 3(2)
*November 28, 2010*

**College Algebra**

Perform the indicated operations 10 − 5[24 ÷ 6 ⋅ 2] 1
*November 28, 2010*

**College Algebra**

can someone tell me how to get a division symbol when posting problems in Algebra
*November 28, 2010*

**College Algebra**

perform the indicated operations 9-3[4-3(2)
*November 28, 2010*

**Physics-Please check**

I said number 4 so I was wrong- Thank you for explaining it and not thinking I'm a complete dope-
*November 21, 2010*

**Physics-Please check**

Which of the following confirms that gravitational mass and inertial mass are equal? I posted this about three hours ago and no one answered it so I'm hoping someone can look at my answer and direct me 1.Free-fall accleration is the same throughout the universe 2.Free fall...
*November 21, 2010*

**Physic-Please help**

Which of the following confirms that gravitational mass and inertial mass are equal? 1.Free-fall accleration is the same throughout the universe 2.Free fall acceleration is the same at all points where the gravitational field stength is the same 3.Newton's second llaw is ...
*November 21, 2010*

**Algebra-Please check**

Write y = 10^(x) as a logarithmic function Choices are log(x)10 = y log(y)x = 10 log(10)y = x log(x)y = 10 I think it is log (10)y = x
*November 16, 2010*

**ap physics **

A 22.7 kg mass attached to a spring scale rests on a smooth, horizontal surface. The spring scale, attached to the front end of a boxcar, reads T = 21.9 N when the car is in motion. If the spring scale reads zero when the car is at rest, determine the acceleration of the car, ...
*November 14, 2010*

**Cal**

How do you find dy/dx by implicit differentiation with respect to x? x^3 + y^5 = 1
*November 8, 2010*

**Physics**

A rotating wheel requires 9.00 s to rotate 29.0 revolutions. Its angular velocity at the end of the 9.00 s interval is 98.0 rad/s. What is the constant angular acceleration of the wheel in radians/second squared? (Do not assume that the wheel starts at rest.)
*November 4, 2010*

**physics**

Make sure you're putting the parenthesis in the correct place. Such as for part A, the formulas should be: a) (ball relative ground) = (Juan's speed)+ (ball relative to Juan) (13.6Cos(32.5))N + (13.6Sin(32.5))E =(7.8)N+(ball relative to Juan) ball relative to Juan= (13...
*November 2, 2010*

**Algeblease check my answer**

Thank you-I see where I made the mistake on the "j"
*October 18, 2010*

**Algebra Please check my answer**

It should have read please check-
*October 18, 2010*

**Algeblease check my answer**

Posted by Annie on Monday, October 18, 2010 at 7:20pm. Choose the equivalent expression(3h^-2j^3k)^2(hj^-5k^3)^-2 The signs that look like minuses are negative signs Answers: 3h^-6j^16K^-4 9h^-2j^5j^16k^-4 9h^-6j^-4k^-4 9h^-6j^-4k^-4 Please help I'm so lost right now-...
*October 18, 2010*

**Math**

I need to graph this equation y=(3/2)sin(3x+2ð)-3. What would the primary interval be for this problem and how would it appear on a graph?
*October 18, 2010*

**Algebra**

Choose the equivalent expression(3h^-2j^3k)^2(hj^-5k^3)^-2 The signs that look like minuses are negative signs Answers: 3h^-6j^16K^-4 9h^-2j^5j^16k^-4 9h^-6j^-4k^-4 Please help-I'm totally lost
*October 18, 2010*

**English - help needed**

Posted by annie on Wednesday, October 13, 2010 at 4:29pm. Are the following sentences semantically / gramatically correct? 1)Alert the supervisor to any defective material found. 2)Some equipment have been taken away for inspection. After inspection, ensure that all the ...
*October 13, 2010*

**English - help needed urgently**

After inspection, ensure that all equipment is accounted for using the checklist given. Is the above sentence acceptable?
*October 13, 2010*

**English - help needed urgently**

Are the following sentences semantically / gramatically correct? 1)Alert the supervisor to any defective material found. 2)Some equipment have been taken away for inspection. After inspection, ensure that all the equipment are accounted for.
*October 13, 2010*

**English**

Can you provide some examples on the use of shall versus should?
*October 10, 2010*

**Chemistry**

In reflux, water normally enters from the bottom of the condenser and exits from the top. What causes water to be able to rise to the top of the condenser? Also, I read from wikipedia website that in the case of the Allihn condenser, water enters from the top. Any idea under ...
*October 9, 2010*

**Chemistry**

In reflux, water normally enters from the bottom of the condenser and exits from the top. What causes water to be able to rise to the top of the condenser? Also, from the following website, it is stated that in the case of the Allihn condenser, water enters from the top. Any ...
*October 9, 2010*

**English**

1) Do we say "The information is correct as of 28 September 2010." or "The information is correct as at 28 September 2010."? 2) "I spoke with him yesterday." or "I spoke to him yesterday."? Someone mentioned to me that both sentences are...
*October 9, 2010*

**Chemistry**

I found the following procedure to prepare starch indicator solution on a website:- To prepare starch indicator solution, add 1 gram of starch (either corn or potato) into 10 mL of distilled water, shake well, and pour into 100 mL of boiling, distilled water. Stir thoroughly ...
*October 6, 2010*

**Algebra**

Is the answer -6? I think I got it
*October 6, 2010*

**Algebra**

How do you solve 2x^2 - 20 = 3x Thank you
*October 6, 2010*

**Algebra**

Thank you
*October 6, 2010*

**Math help please**

calculate missing dimension. square based pyramid has height 92cm and volume 5.4 m cube.
*September 30, 2010*

**Teachers Aide/Language and other Barriers**

my answer is A
*September 27, 2010*

**Chemistry**

How would you usually prepare starch indicator solution for iodine titrations? Can the solution be stored for a few months in the fridge? I noticed that sometimes the starch indicator solution in the fridge has turned cloudy, in which case we should prepare a new solution?
*September 25, 2010*

**physic**

The angular position of a point on the rim of a 45.8 cm rotating wheel is given by θ(t) = 3.6 t2 − 2.8 t +7.5, What is the instantaneous speed v of the point at time t = 6.5 s?
*September 20, 2010*

**Chemistry problem**

I refer to my earlier post on v/v versus w/w. I would be very grateful for any advice provided. For 95% ethanol purchased from manufacturer, we normally take it as 95%v/v. For 98% sulphuric acid, it seems like it is normally 98% w/w. I have also seen a potassium hydroxide 85...
*September 20, 2010*

**Chemistry - v/v versus w/w**

Thanks a lot:) So just to confirm: normally for any chemical bought from manufacturer, if it is not stated, the % usually means v/v? Seems like for conc sulphuric acid, when it is stated 97% sulphuric acid, it means 97% w/w sulphuric acid? Thank you very much. Posted by annie ...
*September 20, 2010*

**Chemistry -repost thank you in advance**

I have a bottle of 95% ethanol purchased from the manufacturer. Normally, when it is not stated, does it mean 95% w/w ethanol? I need to prepare 100ml of 40% v/v ethanol solution from 95% ethanol. Please show me the calculation steps. Thanks.
*September 20, 2010*

**Chemistry- urgent help needed**

How do I prepare 40% v/v from 95% ethanol? When we say 95% ethanol, do we usually mean 95% w/w ethanol unless otherwise stated? Please show me the calculation steps to prepare 40% v/v from 95% w/w ethanol. Thanks.
*September 19, 2010*

**Chemisty - urgent**

Hi, how do I do the calculation? Thanks
*September 15, 2010*

**Chemisty - urgent**

How do I prepare 30% v/v ethanol from 95% ethanol? Thanks.
*September 15, 2010*

**Chemistry **

Sorry,please ignore my earlier post. Light sensitive materials are sampled in a room with yellow lighting. How is it different from normal white light?
*September 14, 2010*

**chemistry**

Light sensitive materials are samples under yellow lighting. Please explain what yellow lighting means.
*September 14, 2010*

**history**

what presidents make up mt rushmore
*August 26, 2010*

**ecology**

Explain atmospheric circulation and seasonal changes in the sun's orientation to earth to explain the highly seasonal rainfall in the tropical dry forest and tropical savanna biomes.
*August 9, 2010*

**ecology**

Why does the rainy season in the tropical dry forest and tropical savanna biomes come during the warmer months?
*August 9, 2010*

**math**

Oh wow, yes. you are right. That does make perfect sense! Sometimes I read to much into a problem. Thank you for simplifying for me Mrs. Sue. :)
*July 30, 2010*

**math**

yes, but .49 does not seem realistic. I may be doing something wrong. Thanks
*July 30, 2010*

**math**

Ok. I pretty much have this one solved but the final answer has me stumped. The probability that Luis will pass his statistics test is 0.51. Find the probability that he will fail his statistics test. This is what I have so far. P(fail)=.51; =1-.51. But I am not sure of the ...
*July 30, 2010*

**Math**

Yeah, I thought so just wasn't sure. Thank you!
*July 30, 2010*

**Math**

Ok. I have one more question. The mean height of 5 students is 59.4. If one of the students leaves, the mean height becomes 61. What is the height of the absent student? I have this so far but still having problems solving it: 5(59.4)=4(61)+1(X);X=? Thank you so much.
*July 30, 2010*

**math/ algebra**

ok, so my final answer is h=2, k=0, r^2=64, then r=8, is this right?
*July 30, 2010*

**math/ algebra**

Yup. That is what I got reiny. :) Thanks again.
*July 30, 2010*

**math/ algebra**

Thank you for your help! The question is what is the center and radius of the circle. (x+2)^2+y^2=64. Thank you so much.
*July 30, 2010*

**math/linear equation**

Yes, you are right! Thank you
*July 30, 2010*

**chemistry**

calculate the number of moles of carbon dioxide in a volume of 50.0 mL of carbon dioxide, assuming a pressure of 1.00 atm and a temperature of 23.0C
*July 27, 2010*

**chemistry**

dot and cross diagram of a molecule of HOCL
*July 11, 2010*

**COLLEGE**

IN A CLASS OF 100 57 STUDENTS RECEIVED A GRADE A WHAT FRACTION DID NOT RECEIVE AN A
*June 4, 2010*

**Algebra**

Evaluate a+b/10 for a=66 and b=4 a+b/10 = (simplify the answer)
*May 26, 2010*

**math**

Three pieces of wood are needed for a project. They are to be cut from a 90-cm-long piece of wood. The longest piece is to be 3 times as long as the middle-sized piece and the shortest piece is to be 10 cm shorter than the middle-sized piece. Can this be done with two cuts? If...
*May 23, 2010*

**spanish**

comer=to eat, tengo=have, yo=I
*May 16, 2010*

**statistics**

Bellevue Hospital in New York City uses 100.6 °F as the lowest temperature considered to indicate a fever. a. (0.1 point) What percentage of normal and healthy adults would be considered to have a fever? : b. (0.1 point) Does this percentage suggest that a cutoff of 100.6...
*May 10, 2010*

**space**

Will a lightbulb pop in space?
*April 19, 2010*

**chemistry**

A 1.00 L volume of helium gas is cooled from 50.0 degrees celcius to 25.0 degrees celcius. If the pressure remains constant, what is the final volume?
*April 19, 2010*

**social studies**

The religion of Islam (Muslums) and Christians are two different groups and cultures. Muslims are strict--can't speak to a woman until they they are engaged, yave to pary 5 times per day, women wear veils, marriages are arranaged, etc...women can't wear bathing suits...
*April 16, 2010*

**6th grade**

what is a word for what happens when you are confused?
*April 15, 2010*

**math**

If Titanic hit an iceberg at 11:40 p.m and 2 hours and 40 minutes later it sank, what time did it sink at?
*April 14, 2010*

**social studies**

What social classes existed in Aryan culture?
*April 6, 2010*

**math**

would (3x^4/15)^2 be x^8/25 when finally simplified?
*February 24, 2010*

**math**

if you had m^0g^0 would you leave it in that form or would the simplified version be 1?
*February 22, 2010*

**mathy**

if you had m^0g^0 would you leave it in that form or would the simplified version be 1?
*February 22, 2010*

**math :( **

Last year you mowed grass and shoveled snow for 10 households. You earned $200 per household mowing for the entire season & $180 per household for shoveling the entire season. If you earned a total of $1880 last year, how many households did you mow and shovel for?! How would ...
*February 9, 2010*

**math**

I totally understand now! i had the 2x+4y=100...i just was blanking out about how to set up the 2nd part but I see now! Thank you so much! :)
*February 7, 2010*

**math**

Your teacher is giving you a test worth 100 points containing 40 questions. There are two-point and four-point questions on the test. How many of each type of question are on the test? How would you set this up?
*February 7, 2010*

**Math**

Use systems of lineear equations to solve: An airplane flew for 6 hours with a 22-km/h tail wind. The return flight against the same wind took 8 hours. Find the speed of the plane in still air. I know the answer is 154 km/hr (back of book resources :) )...I just don't ...
*February 4, 2010*

**physics**

20(2090)(20+6)=1086800 J
*January 27, 2010*

**Science**

What is a bogus analysis using quasi-scientific jargon, but has little or no objectivity.
*January 26, 2010*

**L.A.**

is this a good beginning?!??! The movie, "Swing Kids", is not a light hearted, family film, but rather one that provokes deep emotions and thoughtful thinking within the viewer. This movie contains interesting information that shows the viewer how difficult it was ...
*January 25, 2010*

**space**

What is the force of gravity at 220 miles above Earth's surface? Calculate how much of a g force the astronauts are actually experiencing. The solution for this math problem is a percentage. You can calculate it using the Algebraic equation: gr = R2/r2 x g R = the radius ...
*January 21, 2010*

**which of the folling values repesents an index of **

which of the folling values represents an index of refraction of an actual material
*January 11, 2010*

**Trig**

How do you find csc 163degrees 20minutes? (I didn't know how to insert the degree and minute marks)
*January 10, 2010*

**6th grae math**

how can you add and multiplication at the same time
*January 4, 2010*

**precalculus**

convert the equation y^2 = 2x -x^2 into polar form. convert the equation r = 2tan(theta) into rectangular form. I'm not really sure what either of these mean. I vaguely understand polar coordinates, but I'm not sure how to convert equations back and forth between polar...
*December 6, 2009*

**precalculus**

Two people standing 30 feet apart look east at the top of a tree. The first person looks up at an angle of 78 degrees. The second person looks up at an angle of 62 degrees. How tall is the tree (to the nearest foot)?
*December 6, 2009*

**Algebra**

Sixty-two percent of the students at Kennedy High School are involved in extra curricular activities. If 152 students are not involved in extra curricualr activities, how many students are there at Kennedy High School?
*November 18, 2009*

**math**

thanks
*November 15, 2009*

**math**

i meant what is the mass of the block?
*November 15, 2009*

**math**

what is the density of the block? density is 2700 volume is 10^-4
*November 15, 2009*

**math**

sorry Ana... i missed typed it...again i apologize
*November 15, 2009*

**Physics**

i figured it out..thanks for helping me
*November 15, 2009*

**Physics**

A block of mass m1 = 4.80 kg sits on top of a second block of mass m2 = 15.6 kg, which in turn is on a horizontal table. The coefficients of friction between the two blocks are µs = 0.300 and µk = 0.100. The coefficients of friction between the lower block and the ...
*October 31, 2009*

**Maths**

Find the equation of the normal to the curve y = 3x^2 - 5x that is perpendicular to the line y = x + 4.
*October 23, 2009*

**Com.**

1.Assignment: Negative Messages Using templates or sample documents to help you write e-mails, memos, and letters may be helpful for inexperienced writers; however, customize the communication, so the document does not appear as a form letter. Use the information in your Week ...
*October 18, 2009*

**physics**

Hey thanks! At one point I was using (3/2)R(deltaT) but I wasn't setting it equal to (DeltaQ).
*October 4, 2009*

**physics**

We start with 5.00 moles of an ideal monatomic gas with an initial temperature of 123C. The gas expands and, in the process, absorbs an amount of heat equal to 1300J and does an amount of work equal to 2040J. What is the final temperature of the gas? Use R= 8.3145J/(mol*K) for...
*October 4, 2009*

**6th grade**

The lines of latitude divide the globe into units called what?
*September 10, 2009*

**Geography**

That was pretty quick! Thank you soo much! :D
*September 8, 2009*

**Geography**

What are the capitols of the following countries? 1. Spain 2. Mexico 3. Puerto Rico 4. Peru 5. Venezuela 6. Ecuador 7. Chile 8. Uraguay 9. Argentina 10. Cuba 11. Dominican Republic 12. Bolivia 13. Colombia 14. Paraguay 15. Panama 16. Nicaragua 17. Honduras 18. Guatemala 19. ...
*September 8, 2009*

**Organic Chemistry**

If biphenyl dissolves in both cold and hot methanol, would this be a good recrystallization solvent for biphenyl? Explain please!!!
*August 26, 2009*

**English**

In Great Expectations, what are the three spiritual stages that Pip goes through? What changes in Pip mark each progression into the next?
*July 25, 2009*

**Chemistry**

An ion exchange process may be used to remove ions causing hardness of water. Outline how this works. 1. Ca2+ and Mg2+ are the ions that cause the hardness of water, one example of softening the water is to react the hard water with NaCO3 (Sodium bicarbonate) to soften the ...
*May 30, 2009*