Tuesday

June 28, 2016
Total # Posts: 2,785

**organic chemistry**

Did a grignard experiment where we were supposed to form triphenylmethanol but something went wrong. When we heated up the mixture with the petroleum ether, it didn't solidify, it turned dark and oily. What went wrong?
*March 25, 2013*

**organic chem**

I prepared triphenylmethanol by a grignard reaction. At the end you add petroleum ether to the mixture and heat it up. It stayed a liquid and got dark and oily but never solidified. What went wrong?
*March 25, 2013*

**Stats**

Is noise present in the differenced series (taking non-stationary data and making it stationary thru first difference of a time series)?
*March 23, 2013*

**language arts**

thank you
*March 23, 2013*

**language arts**

what is the past tense of go
*March 23, 2013*

**language arts**

i get it now
*March 23, 2013*

**language arts**

i do not get it
*March 23, 2013*

**language arts**

what is the exact verb of swam
*March 23, 2013*

**Curriculum dev**

Behavior objectives should be written about a behavior that a) is exhibited by most chlldren. B) can actually be seen. C) exhibits all five selves. D) can be evaluated using standardized test. I think a) is exhibited by most children. CAn someone give me some feedback
*March 20, 2013*

**Math**

Find the difference between the perimeter of a square of area 1 centimeter square and the circumference of a circle of the same area.
*March 20, 2013*

**Math**

A lorry travels at 50km/h. Given that the diameter of its wheel is 88cm, find how many revolutions per minute the wheel is turning. Given your answer to the nearest whole number.
*March 20, 2013*

**Math **

Find the speed of a point on the rim of a 24cm diameter fly wheel which is turning at 2800 revolutions per minute. Give your answer in meters per second.
*March 20, 2013*

**Math**

If the minute hand of a big clock is 1.12m long, find the rate at which its tip is moving in centimeters per minute.
*March 20, 2013*

**Math**

As many 8cm diameter discs as possible are cut from a sheet of rectangular cardboard measuring 170cm by 90cm. Find the area of the sheet that is left.
*March 20, 2013*

**Algebra**

You are right on!
*March 19, 2013*

**Physics**

That is why I'm asking. If u don't know, then don't answer my question
*March 19, 2013*

**Physics**

How can we find the resultant force if the mass and SPEED are given?? Give me the formula please!!
*March 19, 2013*

**Statistics**

The eggs of a species of bird have an average diameter of 23 mm and an SD of 0.45 mm. The weights of the chicks that hatch from these eggs have an average of 6 grams and an SD of 0.5 grams. The correlation between the two variables is 0.75 and the scatter diagram is roughly ...
*March 15, 2013*

**Statistics**

A quiz consists of 10 multiple choice questions. Each question is marked either “right” or “wrong.” Each right answer gets 5 points, and 1 point is taken off for each wrong answer. The correlation between the number of right answers and the number of wrong ...
*March 15, 2013*

**Physics 1**

An astronaut in her space suit has a total mass of m1 = 76.9 kg, including suit and oxygen tank. Her tether line loses its attachment to her spacecraft while she's on a spacewalk. Initially at rest with respect to her spacecraft, she throws her oxygen tank of mass m2 = 12....
*March 14, 2013*

**Math**

The cost C in dollars of producing n yearbooks is represented by the equation C=1000+5n How much would it cost to produce 75n yearbooks?
*March 13, 2013*

**biology**

what is deep time?
*March 11, 2013*

**Bioprocessing**

A continuously operated 1000 liter CSTR is used for production of biomass from glucose provided by the feed (feed rate of 100l/h and glucose concentration of 10 g/l). The bacteria show Monod type growth with a maximal specific growth rate of 0.4/h and an affinity towards ...
*March 11, 2013*

**algebra **

Scientists can determine the age of ancient objects by a method called radio carbon dating. The bombardment of the upper atmosphere by cosmic rays converts nitrogen to a radioactive isotope 14C of carbon with a half-life of about 5710 years. Vegetation absorbs carbon dioxide ...
*March 7, 2013*

**Chemistry**

Why is why is CH4+2O2 --> CO2+2H2O very slow at room temperature?
*March 6, 2013*

**math**

9.0
*March 5, 2013*

**7th Math**

30, 2
*March 5, 2013*

**physical science**

The pressure increases because the molecules get squeezed into a tinier space.
*March 3, 2013*

**Science**

How do you balance this equation? Fe2O3+C=Fe+CO2
*February 28, 2013*

**math **

I am not understanding this question. Can someone help me please? Decide whether the experiment is a binomial experiment. If it is not, explain why. Selecting five cards, one at a time without replacement, from a standard deck of cards. The random variable is the number of red...
*February 28, 2013*

**physics**

A 30.343 V emf is placed across a series combination of three resistors (10 Ω, 15.632 Ω, and 64 Ω). At what rate is heat generated in the 15.632 Ω resistor? Answer in units of W
*February 24, 2013*

**ENGLISH**

AWESOME...no one ever told me how to check via the method you mentioned above...that helped me out ALOT!! I got it now :)
*February 23, 2013*

**ENGLISH**

need help with nominative and objective CASE PRONOUNS. these are the ones confusing me... THE POSTAL WORKER DELIVERED A PACKAGE FOR HARRY AND SHE/HER. MY GRANDFATHER AND HER/SHE OPERATED A SMALL INN IN VERMONT. THE COACH PRAISED MANUEL AND HE/HIM. WE'VE BEEN WAITING FOR ...
*February 23, 2013*

**math**

No its wrong it is Marsha Sara Melissa then Juan
*February 22, 2013*

**phisics**

what is the height of the ball if the bottom of the swing is zero, speed is 2.8m/sec, 9.81 acceleration of gravity
*February 21, 2013*

**math**

Dont know
*February 20, 2013*

**Math**

2/7,1/7,1/9,1/12 greatest to least
*February 19, 2013*

**Math**

A man was given $x. He spent 50 cents a day. How much money had he left after A) 10 days? B) 2 weeks? C) t days?
*February 19, 2013*

**Math**

A father is three times as old as his son. In 13 years' time, the father will only be twice as old as his son. Find their present ages. (Please show the solutions clearly)
*February 19, 2013*

**Math**

Ahmad is 7 years older than Bala. Four years ago, Ahmad was twice as old as Bala. Find the sum of their ages in 7 years' time.
*February 19, 2013*

**Math**

Please show the solutions! 1.) x+y-2(2x-3y) 2.) x+y/2 - 3x-y/4 + x-5y/8 3.) 4x- {3x-[(x-3)-2(x-5)]} 4.) a+5b/2 + a-3b/3 - 5(a-b)/6 5.) 2x-5=3x-9 6.) 3x-(2x-7)=2x+3 7.) 7x+2/6 - x-4/3 = x+3/3 8.) 3x-2(x-3)+3(5-2x) 9.) x+1/3 - x-2/4 - x/6 10) 5(2x-5)=3(2x-11) 11) 0.5x+3=1.2x+5.8
*February 19, 2013*

**English 11**

You did not answer my question. Please help me find the rhetorical devices found within the given essay and elaborate. Thank you.
*February 18, 2013*

**English 11**

What are three dominant rhetorical devices in the essay "Where the World Began" by Margaret Laurence?
*February 18, 2013*

**Biology**

Carbon Dioxide
*February 14, 2013*

**Science**

Also, would "What are some stories that is related to the mystery of the Bermuda Triangle?" be a good research question?
*February 14, 2013*

**Science**

How about this one: What are some natural explanations that may have caused disappearances?
*February 14, 2013*

**Science**

I am doing a research project on The Bermuda Triangle. I need to answer three questions but I cannot think of any good research questions for The Bermuda Triangle, any ideas? Thanks!
*February 14, 2013*

**calculus**

If f(x) = 3x^(ln(x)), find f'(10)
*February 12, 2013*

**calculus**

Let f(x) = 2ln(cosx), find f''(x)
*February 12, 2013*

**Calculus**

Find the derivative of y = (ln(2x))/2x
*February 12, 2013*

**Calculus**

Find the derivative of y = (ln(3x))^4
*February 12, 2013*

**Calculus**

Solve for x in the equation ln(16-12x)-2lnx = ln4
*February 12, 2013*

**Calculus**

Solve for x in the equation ln(16-12x)-2lnx)= ln4
*February 12, 2013*

**calculus**

Calculate g'(36^(1/2)), where g is the inverse of f(x) = ((x*x)+16x) for x less than or equal to -16
*February 12, 2013*

**Algebra**

There are 21 people. The number of adults is 3 fewer than 5 times the number of children. How many adults are there? How many kids are there?
*February 10, 2013*

**physics**

Part A, use the following equations: d= vt and x=v(i)t+(1/2)at^2
*February 9, 2013*

**physics**

A charge moves a distance of 1.4 cm in the direction of a uniform electric field having a magnitude of 244 N/C. The electrical potential energy of the charge decreases by 108.3 × 10−19 J as it moves. Find the magnitude of the charge on the moving particle. The ...
*February 8, 2013*

**physics**

A positive test charge of 8.33 × 10−5 C is placed in an electric field of 53.54 N/C intensity. What is the strength of the force exerted on the test charge? Answer in units of N
*February 8, 2013*

**Algebra**

A ladder reaches a height of 16 feet on a wall. If the bottom of the ladder is placed 4 feet away from the wall, what is the slope of the ladde as a positive number?
*February 7, 2013*

**math**

u have 15 white tiles. if u add some black tiles so that 3 out of 4 tiles are white, how many black tiles will u need?
*February 7, 2013*

**physics**

A 1500.0 kg car accelerates uniformly to double its speed from 35.9 km/h in 4.74 s. What net force acted on this car?
*February 5, 2013*

**English**

L The model airplane in my brother's room was made in Germany. Does in my brother's room describe the airplane?
*February 4, 2013*

**English**

We only had to do the one prepositional phrase. What about this one? The plant on the windowsill thrives in the spring. Does in the spring modify thrives?
*February 4, 2013*

**English**

What word is being modified by the prepositional phrase? The monkeys ran from the sound of humans? Is it sound?
*February 4, 2013*

**physics**

Hi, I was wondering if anyone could answer my question. A two head collision. One car is 45000 newtons and going at 15 meters per second. The other car is 9000 newtons and going at 25 meters per second. How would I calculate velocity from this.
*February 4, 2013*

**math**

how many combinations can you get with 18 flavors of ice cream and 70 toppings?
*February 2, 2013*

**math**

find two point the perpendicular bisector of line AB. verify your results by showing each point is equidistant from A and B. A(3,0) B (1,4)
*January 30, 2013*

**Johnson**

How do I record this transaction? Sold inventory on account for $500, cost of merchandise sold was $300. (Record the sale first and then the cost.)
*January 29, 2013*

**Biology**

In a lab experiment, we experimented with 1% glucose solution and Sorenson's solution to determine pH levels and whatnot; the other part of the lab was to determine which one, if either, was a buffering solution. According to the notes my instructor gave us, a buffers are ...
*January 28, 2013*

**Physics **

A ball on the end of a string is whirled around in a horizontal circle of radius 0.486 m. The plane of the circle is 1.83 m above the ground. The string breaks and the ball lands 2.39 m away from the point on the ground directly beneath the ball’s location when the string...
*January 28, 2013*

**Chem**

How can the concept of specific heat capacity of water be used to explain the heating and cooling patterns if the oceans and the climate on the planet?? Can someone please explain this to me it would really help a lot.
*January 27, 2013*

**Hiastory HURRY!!!!!!!!!!!!!!!!!!!!!!!**

The answer is A
*January 24, 2013*

**College Finite**

Assume that you have a total of 9 people on the committee: 2 black males, 1 black female, 1 white male, and 5 white females. Party rules require that at least one black and at least one female hold one of the three offices. In how many ways can the officers be chosen while ...
*January 23, 2013*

**College Finite**

108 is not correct. Thanks for trying tho Reiny!
*January 23, 2013*

**College Finite**

A student wants to buy 3 CDs, but assume that there are 3 CDs featuring the piano, 5 CDs featuring the trumpet, and 3 CDs featuring the saxophone. In how many ways can the selection be made if CD's featuring at least 2 different instruments are selected?
*January 23, 2013*

**chem**

what is the change in enthalpy for CH4(g) + 2O2(g)----->CO2(g)+2H20(I) CH4: -74.86 CO2: -393.5 H2O: -285.5 I got triangle H: 890KJ/Mol is that correct?
*January 22, 2013*

**math- plz hlp**

Thx u very much!
*January 20, 2013*

**math- plz hlp**

The denominator of a fraction is greater than its numerator by 9. If 7 is subtracted from both its numerator and denominator, the new fraction equals 2/3. What is the original fraction?
*January 20, 2013*

**Pre-cal**

A bicycle with 28-in.-diameter wheel is traveling at 15 mph. To the nearest whole number, how many revolutions does each wheel make per minute?
*January 17, 2013*

**English**

In the following sentence is there a direct object or a predicate adjective? Sometimes I feel nervous before a game.
*January 15, 2013*

**fractions greater than one.**

write the mixed number as an improper fraction
*January 14, 2013*

**Physics **

A satellite moves in a circular orbit around the Earth at a speed of 5.4 km/s. Determine the satellite’s altitude above the surface of the Earth. Assume the Earth is a homogeneous sphere of radius 6370 km and mass 5.98 × 10 24 kg. The value of the universal ...
*January 13, 2013*

**physics**

An athlete whirls a 6.6 kg hammer tied to the end of a 1.2 m chain in a horizontal circle. The hammer moves at the rate of 0.432 rev/s. What is the centripetal acceleration of the hammer? Assume his arm length is included in the length given for the chain. Answer in units of m...
*January 13, 2013*

**Physics **

According to the Guinness Book of World Records (1990 edition, p. 169), the highest rotary speed ever attained was 2010 m/s (4500 mph). The rotating rod was 15 cm (5.9 in) long. Assume the speed quoted is that of the end of the rod. What is the centripetal acceleration of the ...
*January 13, 2013*

**physics**

A 1.62 kg mass attached to a light string rotates on a horizontal, frictionless table. The radius of the circle is 0.986 m, and the string can support a mass of 32.5 kg before breaking. The acceleration of gravity is 9.8 m/s 2 . What maximum speed can the mass have before the ...
*January 13, 2013*

**7th grade Social Studies Ms. Sue please!**

1. organize information. 2. enough detail. 3. Earth's tilt and orbit 4. new landforms. 5. latitude. 6. polar. 7. birth rates and death rates. 8. They cannot find work. 9. subsistence farming. 10. city-state. 11. 1. organize information. 2. enough detail. 3. Earth's ...
*January 10, 2013*

**5 th grade math**

Gracie read 150 pages of a book.the book is 227 pages long. Which equation shows the amount she still needs to read to finish the story
*January 10, 2013*

**Chemistry 1**

We are working on molarity of a solution in my class, and I am a little stumped on how to set the problems up. Here is one question from my homework. How many grams of NaCl are needed to make 575mL of 1.5 M NaCl solution? Thank you in advance :)
*January 3, 2013*

**Physics**

We went over this in my physics class yesturday, and I understand most of the concepts of this section of the book, but the examples we were given confuse me. I can find no connection between the numbers of tangential speed and RPM. :(
*January 3, 2013*

**geometry**

Create a word problem about a real life situation involving perimeter and area of a composite shape. I don't know any real life situations involving perimeter and area of a composite shape. Need Help. Please Help.
*December 19, 2012*

**Physics**

A police car is at rest beside a road, looking for speeders. A car passes going at a constant speed of 30.0 m/s. The police car starts up 4 seconds later and accelerates at 2 m/s sq. until it reaches a speed of 40m. If the police car maintains this speed until it catches up ...
*December 18, 2012*

**Social Studies**

natural resources Yankee Zimbabwe I'm studying geography
*December 18, 2012*

**physics**

One strategy in a snowball ﬁght is to throw a snowball at a high angle over level ground. While your opponent is watching this ﬁrst snowball, you throw a second snowball at a low angle and time it to arrive at the same time as the ﬁrst. Assume both ...
*December 16, 2012*

**Physics **

A football is thrown toward a receiver with an initial speed of 17.5 m/s at an angle of 35.2◦ above the horizontal. At that instant, the receiver is 16.7 m from the quarterback. The acceleration of gravity is 9.81 m/s^2 With what constant speed should the receiver run to...
*December 16, 2012*

**physics**

A particle travels horizontally between two parallel walls separated by 18.4 m. It moves toward the opposing wall at a constant rate of 9.4 m/s. Also, it has an acceleration in the direction parallel to the walls of 5.8 m/s^2 What will be its speed when it hits the opposing ...
*December 16, 2012*

**trigonometry**

4.if cotθ = -√15/7 , use the fundamental identities to find cosθ > 0 9.A projectile is fired with an initial velocity of 88 ft/sec at an angle of 35° to the horizontal. Neglecting air resistance, what is the time of impact? (Round to the nearest ...
*December 13, 2012*

**math**

thank you! we just learned decimals to fractions and vice versa today so I thank you for your help and now I can solve the remainder of the problem myself. thank you!
*December 11, 2012*

**math**

what is 1 3/4 as decimal
*December 11, 2012*

**Chemistry**

Hi, i'm really desperate! could anyone please help me with this question, I'm stumped. 'A buffer is prepared by mixing a 100.omL of a 0.100 M NH3 solution with a 0.200M solution of NH4CL solution and making the total volume up to 1.000L of water. What is the volume...
*December 11, 2012*