Wednesday

January 18, 2017
Total # Posts: 1,151

**Chemistry**

Calculate the heat given off when 177 g of copper cools from 155.0 c to 22.0 c. The specific heat capacity of copper is 0.385 j/g c

*January 23, 2014*

**Statistics**

In an essay of 250-500 words, thoroughly address the following items and respond to the related questions: 1.Define the term standard deviation. Why is it important to know the standard deviation for a given sample? What do researchers learn about a normal distribution from ...

*January 23, 2014*

**physics**

Which of the following was explained by the Bohr atom? 1. atomic spectra 2. the fact that most of the mass of an atom is in the nucleus 3. nuclear fission 4. the photoelectric effect

*January 22, 2014*

**Maths**

prove that 2+2=5

*January 9, 2014*

**Math**

For the integers from 1 to 1000, how many multiples of 9 are also multiples of 6?

*January 2, 2014*

**Math**

I don't get what you mean?

*January 2, 2014*

**Math**

Bob the builder has many sticks of length 3, 5, and 7. He wants to form triangles whose edges consist of exactly 1 stick. How many non-congruent triangles can he form with the sticks?

*January 2, 2014*

**Algebra**

What is the sum of all coefficients of the polynomial? f(x)= (3x^3 - 3x - 1)^38 * (2x+1)^4 * (x^4 - 3x^2 + 5x - 2)^77

*November 25, 2013*

**math**

I think term 55 but I am not sure what that proves or if it shows you the answer?

*November 25, 2013*

**Physics**

X rays bombarding heavy atoms can be used to eject electrons from the 1s shell in atoms; indeed, this is the starting point for Moseley’s experiments. Estimate the maximum wavelength of pho- tons required to eject an electron from the 1s shell of copper, for which Z = 29...

*November 21, 2013*

**Physics**

A 100-watt bulb becomes warm and glows brightly enough to light a small room. On the other hand, a 100-watt laser can cut holes in steel and would not be effective at lighting a small room. What is true about the light coming from these two sources that accounts for these dif...

*November 21, 2013*

**Social Science**

I have to conduct a project that will be time consuming and costly and I need to justify to my principal investigator why he should approve the funding for this project.

*November 15, 2013*

**Phsyics**

How might they use spectroscopy to deter- mine the atmospheric composition of these planets? 1. None of these 2. By analyzing the spectrum of the surface of the planets. 3. All of these 4. By analyzing the molecules that compose the planets. 5. By analyzing the spectrum of the...

*November 13, 2013*

**english**

unscramble the words in the following sentence to write sensible sentences : underline common noun the was about One an West old outlaw film in.

*November 7, 2013*

**chemistry**

N2 + 2O2 -->2 NO2 Suppose 31.25 g of N and 44.0 G of O react A. Calculate the mass of Nitrogen Dioxide formed. B. Which reactant is the limiting reactant? C. Calculate the mass of the excess reactant left after the reaction. D. Find the % yield if 52.3 g of NO2 is produced.

*October 30, 2013*

**physics**

P=w/t =F*x/t =m*a*x/t =200kg*9.8m/s^2*6m/3600s ?3.267W =(3.267W/1)*(1hp/746W) ?0.00438hp

*October 24, 2013*

**physic**

A 2.25kg book is dropped from a height of 2.5m what is the acceleration?

*October 22, 2013*

**Physics**

Two ice skaters, Daniel (mass 70.0kg ) and Rebecca (mass 45.0kg ), are practicing. Daniel stops to tie his shoelace and, while at rest, is struck by Rebecca, who is moving at 14.0m/s before she collides with him. After the collision, Rebecca has a velocity of magnitude 6.00m/s...

*October 17, 2013*

**Physics**

A 4.2 g bullet leaves the muzzle of a riﬂe with a speed of 372.4 m/s. What constant force is exerted on the bullet while it is traveling down the 0.5 m length of the barrel of the riﬂe? Answer in units of N

*October 15, 2013*

**Math**

The admission fee at an amusement park is 1.5 dollars for children and 4 dollars for adults. On a certain day, 294 people entered the park, and the admission fees collected totaled 716 dollars. How many children and how many adults were admitted

*October 9, 2013*

**Algebra**

A man invests his savings in two accounts, one paying 6 percent and the other paying 10 percent simple interest per year. He puts twice as much in the lower-yielding account because it is less risky. His annual interest is 418 dollars. How much did he invest at each rate?

*October 9, 2013*

**Vocabulary Studies**

Imagery is figurative language that evokes mental pictures, usually by appealing to our five senses. Imagine that you are standing on the beach in the picture. Write a paragraph of at least 5 complete sentences using imagery to describe your imagined experience. Use at least 3...

*September 28, 2013*

**Chemistry**

Table salt, NaCl, and sugar C12H22O11 are accidentally mixed. A 5.50g sample is burned and 3.60g of CO2 is produced. What was the mass percentage of the table salt mixture?

*September 23, 2013*

**Vocabulary Studies**

Imagine that you are standing on the beach in the picture. Write a paragraph of at least 5 complete sentences using imagery to describe your imagined experience. Use at least 3 examples of language that appeals to your 5 senses: taste, touch, hearing, sight, and smell

*September 22, 2013*

**Physics 2**

A 1.00-L insulated bottle is full of tea at 88.0°C. You pour out a mug of tea and immediately screw the stopper back on the bottle. Find the change in temperature of the tea remaining in the bottle that results from the admission of air at room temperature. (Let the room ...

*September 17, 2013*

**Physics 2**

A 1.00-L insulated bottle is full of tea at 88.0°C. You pour out a mug of tea and immediately screw the stopper back on the bottle. Find the change in temperature of the tea remaining in the bottle that results from the admission of air at room temperature. (Let the room ...

*September 17, 2013*

**algebra**

if f(X)=x^1/3+ 1/3x what is the value of f(27)

*September 15, 2013*

**College Physics II**

A steel wire and a copper wire, each of diameter 2.000 mm, are joined end to end. At 48.0°C, each has an unstretched length of 2.000 m. The wires are connected between two fixed supports 4.000 m apart on a tabletop. The steel wire extends from x = −2.000 m to x = 0, ...

*September 3, 2013*

**Fourth grade math**

What is the sum of the six three-digit numbers that have the digits 2, 4, and 6?

*August 30, 2013*

**Fourth grade math**

What is the sum of the six three-digit numbers that have the digits 1, 2, and 3? What is the sum in each column? Why is the sum in each column the same? my mom doesn't know how to help me with this one?

*August 30, 2013*

**College Physics II (Calc-Based)**

Okay so my equation was set up correctly and should read.. (1.00x10^-9)(1.90m^3)/(8.314x308.15) Correct? So my R would be 2.67724^-12?

*August 29, 2013*

**College Physics II (Calc-Based)**

In state-of-the-art vacuum systems, pressures as low as 1.00 x 10^-9 Pa are being attained. Calculate the number of molecules in a 1.90-m^3 vessel at this pressure and a temperature of 35.0°C. Okay. So I know I have to use the Ideal Gas Law, PV = nRT, I then transformed it...

*August 29, 2013*

**physics**

A roller coaster at an amusement park has a dip that bottoms out in a vertical circle of radius 11.0 m. A passenger feels the seat of the car pushing upward on her with a force equal to three times her weight at the bottom of the dip. What is her speed as she goes through the ...

*July 29, 2013*

**Statistics**

True or False. Help please! Statistics' students of a class of Lyceum want to calculate the average number of chocolate pieces in a standard package of biscuits SANTAS. They choose a random sample of biscuits, measure chocolate pieces in each cookie and calculate the 95% ...

*July 28, 2013*

**Statistics**

I am confused.. maybe is D. I am copying this paragraph from wikipedia. Meaning and interpretation[edit] For users of frequentist methods, various interpretations of a confidence interval can be given. The confidence interval can be expressed in terms of samples (or repeated ...

*July 26, 2013*

**Statistics**

Thank you PsyDAG. Are yousure about B? I believe that B is correct but maybe A is correct. I have to choose only one.. You believe B is absolutely correct?? Can you help me and with the other one please?

*July 26, 2013*

**Statistics**

Oh no.. Maybe the correct answer is A!!

*July 26, 2013*

**Statistics**

Multiple Choice Which of the following statements is true about the 95% confidence interval of the average of a sample? A) 95 of 100 avgs of samples will be within the limits of the confidence interval. B) There is a 95% chance the avg of the population to be within the limits...

*July 26, 2013*

**Statistics**

I forgot to state my answer. 1) True 2) False 3) True 4) False. Do you agree?

*July 26, 2013*

**Statistics**

True or False Questions. Statistics' students of a class of Lyceum want to calculate the average number of chocolate pieces in a standard package of biscuits SANTAS. They choose a random sample of biscuits, measure chocolate pieces in each cookie and calculate the 95% ...

*July 26, 2013*

**Statistics**

Any ideas please? Simple random sample of voters will be taken in a large state. Researchers will construct an approximate 95% confidence interval for the percent of the state¢s voters who will vote for Candidate A. Find the minimum sample size needed to ensure that the ...

*July 24, 2013*

**Statistics**

I believe that: a) is False b) is True c) Is False. Any suggestions?

*July 22, 2013*

**Statistics**

True or False Question. I need help please. A sientific paper reports the results of a drug test. This medicine used to reduce vision loss in people suffering from macular degeneration. The article state p = 0,04 section findings. The following issues are of three different ...

*July 22, 2013*

**chem 103**

Question..where to start..If you had 250.0 g of copper (specific heat = 0.385), what temperature could you raise it to (starting from 20 degrees C) if you heated it with 1685 Joules of energy? If I use the formula q=MxCsX^T, How do I find ^T if I do not have a Tf, assuming 20....

*July 21, 2013*

**Statistics**

Yeah... I think you are absolutely correct. Also from the city is very possible to be there in 10 minutes so he will pay more for the parking. I changed my mind... Thank you a lot.

*July 20, 2013*

**Statistics**

S. Sue, Thank you. To be honest i was not sure about c.. I am between a and c.. More positive on c.. Are you sure?

*July 20, 2013*

**Statistics**

I need help with this please. It is a multiple choice question, so choose one from a,b,c please. I believe the correct is c. What do you think? Ari lives about 10 minutes away from the college to which he intend to attend a summer seminar of 10 weeks. There are two main routes...

*July 20, 2013*

**Statistics**

Thank you very much PsyDAG. can you help me with the other one i posted related to this please? (multiple choice)

*July 20, 2013*

**Statistics**

I need help with this please. A researcher is designing a research study. He hopes to show that the results of an experiment are statistically significant. What size of p value would take? a) Large value of p b) Small value of p c) The size of the p value does not affect the ...

*July 20, 2013*

**Statistics**

An environmentalist do a study to investigate the effects of a specific herbicide in fish. Has 60 healthy fish and randomly distributes any fish or in the experimental group or the control group. The fish in the experimental group have higher indices enzymes. 1) Suppose that ...

*July 19, 2013*

**Statistics**

Dear MathMate, Thank you for the paper it will be very usefull for me! As I understand from this paper i was correct? a) is False b) is True c) Is False. Thank you in advance.

*July 19, 2013*

**Statistics**

Hello PsyDAG. I do not know. The question is given exactly as you see. I believe that this is tricky. Maybe wants to think that of course the demand of the researchers is the medicine is effective. So the null hypothesis is exactly the opposite (no difference). Do you agree? ...

*July 19, 2013*

**Statistics**

A research article reports the results of a drug test. This medicine used to reduce vision loss in people suffering from macular degeneration. The article state p = 0,04 section findings. The following issues are of three different interpretations of this value p. Note which ...

*July 19, 2013*

**math**

Padding 7 miles upstream, Steven and his brother averaged 2 miles per hour. On the way back, their rate of speed was 3 1/2 miles per hour. How long did it take them to make the round trip?

*July 16, 2013*

**math**

A computer train travels the distance from Acton to Boston in 1 hour and 10 minutes. If the train is traveling at an average speed of 48 miles per hour, what is the distance between the two cities?

*July 16, 2013*

**chem 103**

Thank you for your time! Obviously I need to review the equation set-ups again. You were very helpful!

*July 14, 2013*

**chem 103**

Thank you so much! Now for the second part of the question. How many ml of that stock solution would you need to prepare 175 ml of 0.750 M diluted Na3PO4 solution? My answer is 4.27 ml of stock solution. Is that correct? Thank you. If yes , the next part of the question is: if...

*July 14, 2013*

**chem 103**

Still stuck on this question. How many grams of Na3PO4 would you need to make 0.225L of 8.0M stock solution? 8.0 M of NaPo multiplied by .225L NaPO = 1.8 mols of Na3PO4. Then multiply the 1.8 mol times the mass of Na3PO4 which is 163.93 grams?, yes? This would make 295.07 ...

*July 14, 2013*

**algebra 2**

sorry ax-bx=2a

*July 11, 2013*

**algebra 2**

solve equation for x atate any restrections ax-bx+2a

*July 11, 2013*

**College 103 Chem**

How many grams of Sodium Phosphate would you need to make 225ml of 8.00M of stock solution? Thank you

*July 10, 2013*

**Math**

CHEATER!!!!! do not answer this. this is an ongoing problem on brilliant . org. Be ashamed of yourself, "best".

*June 18, 2013*

**physics**

A car is hauling a 89 kg trailer, to which it is connected by a spring. The spring constant is 2100 N/m. The car accelerates with an acceleration of 0.29 m/s2. By how much does the spring stretch?

*June 14, 2013*

**pls heeelp math**

Please stop cheating, mathslover. I will delete your account on Brilliant if you continue this behavior. -Calvin

*June 7, 2013*

**plls heeeeeeelp math**

How many ordered pairs of positive integers 1≤k≤n≤50 are there, such that k divides n, and (n/k )!= n!/k! ?

*June 4, 2013*

**heeeeeeeeelp math**

is it ? are you know my Brilliant Accout? hahaha freaking stupid threat

*June 3, 2013*

**heeeeeeeeelp math**

How many ordered pairs of positive integers 1≤k≤n≤50 are there, such that k divides n, and (n/k )!= n!/k! ?

*June 3, 2013*

**heeelp tooough physics**

A tunable capacitor (with variable capacitance) is charged by a U 0=12 V battery and then is connected in parallel to a R=3 Ω resistor. The capacitance C(t) of the capacitor is controlled so that the current in the circuit remains constant at all times. What is the power...

*June 1, 2013*

**heeeeeeelp geometry**

In a triangle ABC, BK is an angle bisector. A circle with radius 5/3 passes through the vertex B, intersects AB at a point L, and is tangent to AC at K. It is known that the length of AC is 3√3, and the ratio of the lengths |AK| to |BL| is 6:5. The area of the triangle ...

*June 1, 2013*

**heeeeeeeeeelp math**

Miles has 4 Lego people in his Lego town. A Lego person consists of exactly 1 set of legs, a torso, and a head. All of these body parts are distinct. Miles' son comes in and takes apart the Lego people. How many different sets of 4 Lego people can be created from the pieces?

*June 1, 2013*

**heeeeeeeeeeeeelp math**

ur answer was wrong

*June 1, 2013*

**heeeeeeeeeeeeelp math**

Miles has 4 Lego people in his Lego town. A Lego person consists of exactly 1 set of legs, a torso, and a head. All of these body parts are distinct. Miles' son comes in and takes apart the Lego people. How many different sets of 4 Lego people can be created from the pieces?

*June 1, 2013*

**heeeeeeeelp math**

Let x,y,z be non-negative real numbers satisfying the condition x+y+z=1 . The maximum possible value of x^3*y^3+y^3*z^3+z^3*x^3 has the form a/b where a and b are positive, coprime integers. What is the value of a+b ?

*May 31, 2013*

**heeeeeeelp math**

Miles has 4 Lego people in his Lego town. A Lego person consists of exactly 1 set of legs, a torso, and a head. All of these body parts are distinct. Miles' son comes in and takes apart the Lego people. How many different sets of 4 Lego people can be created from the pieces?

*May 30, 2013*

**heeeelp physics**

A tunable capacitor (with variable capacitance) is charged by a U 0=12 V battery and then is connected in parallel to a R=3 Ω resistor. The capacitance C(t) of the capacitor is controlled so that the current in the circuit remains constant at all times. What is the power...

*May 30, 2013*

**pllllls heeeeeeeeelp math**

Let x,y,z be non-negative real numbers satisfying the condition x+y+z=1 . The maximum possible value of x^3*y^3+y^3*z^3+z^3*x^3 has the form a/b where a and b are positive, coprime integers. What is the value of a+b ?

*May 30, 2013*

**math plllls heelp**

How many integers 1≤N≤1000 can be written both as the sum of 26 consecutive integers and as the sum of 13 consecutive integers?

*May 29, 2013*

**heeeeeeeeeeeeeeeeeeeelp maths**

In triangle ABC, points D,E,F are on sides BC,CA,AB respectively such that AD,BE,CF are angle bisectors of triangle ABC. The lines AD,BE,CF are concurrent at I, the incenter of triangle ABC. If ∠BAC=92∘, what is the measure (in degrees) of ∠EIF?

*May 28, 2013*

**help math**

In triangle ABC, points D,E,F are on sides BC,CA,AB respectively such that AD,BE,CF are angle bisectors of triangle ABC. The linesAD,BE,CF are concurrent at I,the incenter of triangle ABC. If Angle BAC=90, what is the measure (in degrees) of Angle EIF?

*May 28, 2013*

**help maths**

f(x) is a cubic polynomial such that f(n)=1/n^2+1 for n=1,2,3,4. If f(0)=a/b,where a and b are coprime positive integers, what is the value of a+b

*May 28, 2013*

**geometry**

A rectangular prism has a volume of 250 cubic cm.What would the volume be if one dimension stayed the same, a second dimension was three times as long, and the third was twice as long?

*May 23, 2013*

**Probability**

Andrew has ten different two-player board games on his shelf. He has them numbered 1 through 10. When he plays the game i against Diego, he has a i^2/100 chance of winning. If Andrew rolls a fair ten-sided die to determine which game to play, the probability that he will win ...

*May 20, 2013*

**Geometry**

ABC is a triangle with a right angle at A. M and N are points on BC such that AM is the altitude, and AN is the angle bisector of ÚBAC. If CN/NB =21 , what is CM/MB ?

*May 16, 2013*

**Algebra**

Suppose x and y are real numbers and 4x+3xi+yi−43=2y+2xi−x+2yi+5i . What is the product xy .

*May 15, 2013*

**Science**

Two point charges +q=1 ìC and −q=−1 ìC with mass m=1 g are fixed at the positions ±r ⃗ 0 with |r 0 |=1 m . The charges are released from rest at t=0 . Find the time ô in seconds at which they collide.

*May 15, 2013*

**math**

what is a pentagon

*May 13, 2013*

**algebra**

4x-3y=24

*April 28, 2013*

**MATH**

What is 10 3/7 as a percent and a decimal

*April 21, 2013*

**accounting**

Ziegler Corporation purchased 25,000 shares of common stock of the Sherman Corporation for $40 per share on January 2, 2010. Sherman Corporation had 100,000 shares of common stock outstanding during 20 I3, paid cash dividends of $120.000 during 20 I3, and reported net income ...

*April 20, 2013*

**College Physics**

A uniform ladder of mass, m, and length, l, leans at an angle, theta, against a frictionless wall. Determine a formula for the minimum angle at which the ladder will not slip.

*April 20, 2013*

**College Physics**

A large 61.0 kg board is propped at a 45 degree angle against the edge of a barn door 2.9m wide. How great a horizontal force must a person behind the door exert (at the edge) in order to open it? Assume that there is negligible friction between the door and the board but that...

*April 20, 2013*

**College Physics**

A cubic crate of side s=2.0m is top-heavy: its CG is 18cm above its true center. Part A) How steep an incline can the crate rest on without tipping over? Part B) What would your answer be if the crate were to slide at constant speed down the plane without tipping over? (The ...

*April 20, 2013*

**chemistry**

URGENT THANKYOU

*April 17, 2013*

**chemistry**

C2H5OH+O2-CH3COOH+H2O HOW MANY MOLES OF ETHANOL IN 5g

*April 17, 2013*

**math**

The floor for people that don't know what floor they want to go on

*April 17, 2013*

**language arts & writing**

probably c if i were to guess

*April 15, 2013*

**chemistry (electrochemistry)**

1) For the following electrochemical cell Cu(s)|Cu2 (aq, 0.0155 M)||Ag (aq, 1.50 M)|Ag(s) write the net cell equation. Calculate the following values using standard potentials as needed. Eo cell and dGo for each reaction...

*April 15, 2013*

**chemistry**

A current of 3.78 A is passed through a Pb(NO3)2 solution for 1.40 hours. How much lead is plated out of the solution?

*April 15, 2013*

**accounting**

Hillsborough Co. has an available-for-sale investment in the bonds of Schuyler with a carrying (and fair) value of $ 85,540. Hillsborough determined that due to poor economic prospects for Schuyler, the bonds have decreased in value to $ 59,710. It is determined that this loss...

*April 14, 2013*

**accounting**

Rushia Company has an available-for-sale investment in the 10%, 10-year bonds of Pear Co. The investment’s carrying value is $3,200,000 at December 31, 2010. On January 9, 2011, Rushia learns that Pear Co. has lost its primary manufacturing facility in an uninsured fire. ...

*April 14, 2013*