Tuesday

June 30, 2015

June 30, 2015

Total # Posts: 116

**Chemistry**

Thank you both so much! This makes much more sense then what I was trying to read from the textbook.
*June 9, 2015*

**Chemistry**

Could a buffer system employing H3PO4 as the weak acid and H2PO4^- as the weak base be used as a buffer system within cells? Explain. I know the answer is no but I'm not really quite sure how to explain why.
*June 9, 2015*

**Chemistry**

I've tried it by changing mmHg to atm and I still get 61.1L
*February 22, 2015*

**Chemistry**

That is the equation that I used. P1V1T2/T1P2 = (736mmHg x 25.6 L x 304.9 K)/(365mmHg x 257.4K) = 61.1 L
*February 22, 2015*

**Chemistry**

The answer I got is 61.1 L but this is not correct. I do not understand what I am doing wrong.
*February 22, 2015*

**Chemistry**

A weather balloon is inflated to a volume of 25.6L at a pressure of 736mmHg and a temperature of 31.9∘C. The balloon rises in the atmosphere to an altitude, where the pressure is 365mmHg and the temperature is -15.6∘C. Assuming the balloon can freely expand, ...
*February 22, 2015*

**Chemistry**

A student is instructed to standardize an approximately 2.5N KOH solution using a 0.500N H2SO4 stock solution. Describe the experimental procedure he/she must follow. I do not understand what procedure needs to be followed.
*January 26, 2015*

**Chemistry**

Why is the carbonate solution boiled before titrating?
*January 18, 2015*

**chem/math**

A car traveling with a constant speed travels 150km in 7200s. What is the speed of the car?
*January 12, 2015*

**Chemistry**

Thank you very much! this makes much more sense now! I really appreciate your help.
*January 12, 2015*

**Chemistry**

1.984 g of a hydrate of K2CO3 is dissolved in 250. mLs of H2O. 10.0 mLs of this solution is tirade against 0.100 M HCl, producing the following results. Flask 1 - Initial 0, final 9.2 Flask 2 - Initial 9.2, final 18.3 Flask 3 - initial 18.3, final 27.8 Flask 4 - initial 27.8, ...
*January 12, 2015*

**Math**

A ladder 10 ft long leans against a wall. The bottom of the ladder is 6 ft from the wall. How much would the lower end of the ladder have to be pulled away so that the top end would be pulled down by 3 ft?
*December 7, 2014*

**Physics**

Batman (mass = 75.6 kg) jumps straight down from a bridge into a boat (mass = 631 kg) in which a criminal is fleeing. The velocity of the boat is initially +10.4 m/s. What is the velocity of the boat after Batman lands in it?
*December 4, 2014*

**Physics**

A 2.86-g bullet, traveling at a speed of 452 m/s, strikes the wooden block of a ballistic pendulum, such as that in Figure 7.14. The block has a mass of 230 g. (a) Find the speed of the bullet/block combination immediately after the collision. (b) How high does the combination...
*December 4, 2014*

**Chemistry**

A 10.00 ml sample of vinegar, density 1.01g/ml, was diluted to 100.0ml volume. It was found that 25.0 ml of the diluted vinegar required 24.15ml of 0.0976 M NaOH to neutralize it. Calculate the strength of CH3COOH in terms of: a) molarity b) grams CH3COOH per litre c) % ...
*November 18, 2014*

**Physics**

The helicopter in the drawing is moving horizontally to the right at a constant velocity. The weight of the helicopter is W=54300 N. The lift force L generated by the rotating blade makes an angle of 21.0° with respect to the vertical. (a) What is the magnitude of the lift...
*October 27, 2014*

**english**

compare and contrast themes in the crucible and the film pleasantville
*October 16, 2014*

**Physics**

A bird watcher meanders through the woods, walking 1.10 km due east, 0.624 km due south, and 1.09 km in a direction 18.2 ° north of west. The time required for this trip is 1.046 h. Determine the magnitudes of the bird watcher's (a) displacement and (b) average velocity.
*October 5, 2014*

**Physics**

A police car is traveling at a velocity of 20.0 m/s due north, when a car zooms by at a constant velocity of 44.0 m/s due north. After a reaction time 0.700 s the policeman begins to pursue the speeder with an acceleration of 6.00 m/s^2. Including the reaction time, how long ...
*September 29, 2014*

**Physics**

rom the top of a cliff, a person uses a slingshot to fire a pebble straight downward, which is the negative direction. The initial speed of the pebble is 7.56 m/s. (a) What is the acceleration (magnitude and direction) of the pebble during the downward motion? (b) After 0.950 ...
*September 29, 2014*

**life orientation**

identify three study fields/ career paths in order of preference and provide two reasons for each choice
*June 4, 2014*

**Statistics**

Hi, Are market returns (with numbers such as -3.45, 4, 2.456 representing the "returns") ordinal or nominal data? Thanks!
*April 18, 2014*

**Chemistry**

Calculate the number of moles of ag in 5ml of .004m agno3 and the number of moles of cr04 in 5ml of .0024m k2cro4
*March 19, 2014*

**Economics**

According to the following game tree, and if the entrant and incumbent both only care about their own monetary payoff, what is/are the game's Nash equilibrium? Entrant - stays out (2,15) - enters If the entrant enters, Incumbent - co operates (5,5) - punishes (-3,9) So ...
*May 14, 2013*

**finance **

Calculate the IRR of the following project: Year Cash Flow 0 -$30,000 1 $40,000
*May 6, 2013*

**L.O**

identify and describe 3 environmental heath hazards that cause ill health,crises,and or any other community within south africa and globally.
*April 29, 2013*

**Math**

When f(x)is divided by x-1 and x+2,the remainders are 4 and -2 respectively . Hence find the remainder when f(x)is divided by x^2+x-2 .
*April 20, 2013*

**Economics**

Hi, The demand for inflatable garden gnomes is given by P = 300 – 2Q, while the supply of is P= 100 + Q/2. How many garden gnomes are traded in equilibrium? I found the answer to be Q = 80. The related question was the one I had difficulty with: Suppose that the market ...
*April 10, 2013*

**algebra**

Which property would allow you to use mental computation to simplify the problem 27 + 15 + 3 + 5?
*April 1, 2013*

**physics**

Mason lifts a box off the ground and places it in a car that is 0.50 meters high. If he applies a force of 8.0 newtons to lift this suitcase, what is the work done?
*January 25, 2013*

**gvernemnt**

purpose of a filibuster is to
*November 26, 2012*

**Physics**

A soccer player kicks a football frombground level with an initial velocity of 27.0m/s, 30deg. Solve for the: A. Ball's hang time B. Range C. Max Height Ignore air resistance. (Hint: hang time refers to the time the ball is in the air.)
*November 21, 2012*

**financial management**

Suppose you invest $2,500 in an account bearing interest at the rate of 14% per year. What will the future value of your investment in six years?
*November 20, 2012*

**Math**

Use mathematical induction to prove that 2^(3n) - 3^n is divisible by 5 for all positive integers. ThankS!
*October 22, 2012*

**maths urgent please**

a particle moves in a straight line such that its position x from a fixed point 0 at time 't' is given by x= 5 + 8sin2t + 6cos2t 1. Find the period and amplitude of the particle. 2. Find the greatest speed of the particle. Could you please explain the steps on how to ...
*October 22, 2012*

**maths urgent please**

the chord PQ joining the points P(2p, p^2) and Q(2q, q^2) on x^2 = 4ay always passes through the point A(2,0) when produced. show that (P+q) = pq thanks!
*October 20, 2012*

**Math**

A particle is projected horizontally with velocity V m/s, from a point h meters above ground. Taking g ms^-2 as the acceleration due to gravity, 1. Show the equation of the path is given by y = (2hV^2 - gx^2)/ 2V^2 2. Find the range of the particle. Thanks
*October 20, 2012*

**Math**

By using the expansion (1 + x)^2. Prove 8[sigma notation]k=0 2^(3K)(N K) = 3^(2n). Thanks
*October 20, 2012*

**Mathematics**

Can you please explain how to get the answers please?
*October 20, 2012*

**Mathematics**

a particle moves in a straight line such that its position x from a fixed point 0 at time 't' is given by x= 5 + 8sin2t + 6cos2t 1. Find the period and amplitude of the particle. 2. Find the greatest speed of the particle. Thanks
*October 20, 2012*

**maths **

by equating the coefficients of sin x and cos x , or otherwise, find constants A and B satisfying the identity. A(2sinx + cosx) + B(2cosx - sinx) = sinx + 8cosx I got A = 2, B = 3, which the answers said were correct. However, another part of the question asked hence integrate...
*October 19, 2012*

**Math**

Prove by induction that 9^(n+2)- 4n is divisible by 5 for n greater than or equal to 1. Thanks.
*October 19, 2012*

**maths **

A box contains 20 balls, of which 5 are red, 5 are blue, 5 are white and 5 are green. Suppose a sample of 5 balls are chosen without replacement. a) find the probability that the sample contains balls of all the same colour (answer is 4/ 20C5, but why isnt it 5/20C5??) b) find...
*October 11, 2012*

**Math**

Find the probability that if the letters of the word "parallel" are randomly arranged that the L's will not be together. In class, I'm studying permutations and combinations. The solutions stated the no. of permutations where 3 L's are together is 6!/2!. ...
*October 11, 2012*

**Economics**

Find the future value one year from now of a $7,000 investment at a 3% annual compound interest rate. Also calculate the future value if the investment is made for 2 yeaars?
*August 20, 2012*

**MATH**

You are interested in finding out if a student’s ACTscore is a good predictor of their final college grade point average(GPA). You have obtained the following data and are going to conduct a regression analysis. Follow instructions on page 324 of your textbook under line ...
*August 20, 2012*

**math**

could you please help with this question :) Find the speed and direction of a particle which, when projected from a point 15 m above the horizontal ground, just clears the top of a wall 26.25 m high and 30 m away. Thanks in advance
*July 15, 2012*

**math**

A batsman hits a cricket ball 'off his toes' towards a fieldsman who is 65 m away. The ball reaches a maximum height of 4.9 m and the horizontal compoenent of its velocity is 28 m/s. Find the constant speed with which the fieldsman must run forward, starting at the ...
*July 15, 2012*

**Math**

A batsman hits a cricket ball 'off his toes' towards a fieldsman who is 65 m away. The ball reaches a maximum height of 4.9 m and the horizontal compoenent of its velocity is 28 m/s. Find the constant speed with which the fieldsman must run forward, starting at the ...
*July 14, 2012*

**Math**

Hi, could you please help with this question :) Find the speed and direction of a particle which, when projected from a point 15 m above the horizontal ground, just clears the top of a wall 26.25 m high and 30 m away. Thanks in advance
*July 14, 2012*

**Finance**

13.4%
*June 17, 2012*

**Math**

Evaluate the integral from 0 to sqrt3 cot^-1(x) dx. Thanks :)
*April 19, 2012*

**Math**

The region above the curve y = sin^-1(x), (0 greater than or equal to y greater than or equal to pi/4), is rotated about the y-axis through a complete revolution to form a solid. Evaluate the volume. Thanks!
*April 19, 2012*

**Math**

Evaluate the integral from 0 to 4 of (x+1)/(16+x^2) dx the answers are log(sqrt2) + pi/16 Could you please take me through how to get to that answer please, thank you very much!
*April 19, 2012*

**general chemistry**

How much heat in kilojoules is evolved in converting 1.50moles of steam at 150 degrees celcius to ice at -60.0 degrees celcius? The heat capacity of steam is 1.84J/g degree C and that of ice is 2.09J/g degree C.
*April 3, 2012*

**math**

the lawn order lawnmower factory can produce 12 lawnmowers in 8 hours. How many hours will it take the actory to produce 30 lawnmowers.
*February 15, 2012*

**Math**

I have a box that is 15cm-wide, 10cm-long, and 3cm- wide. To get it's volume I would add all the sides. Thanks
*January 16, 2012*

**English **

Hi, I have to write up paragraphs on these themes from Frankenstein: a) good vs. evil (manichean) b) duty of responsibility c) nature vs. nurture However, I'm confused about what the differences between these points are... For example, in "nature vs. nurture", ...
*December 26, 2011*

**Math **

A circular piece of wire has a radius of 12 cm. This is cut then bent to form an arc of a circle whose radius is 60 cm. Find the angle subtended at the centre by this arc. Give your answer to the nearest degree. Please show working out Thank you so much!
*December 9, 2011*

**Maths **

What is the area of the minor segment cut off a circle of radius 10 cm by a chord of length 12 cm? Could you please show me the working out for this question? The answer in the textbook is 16 sq cm. Thanks!!!
*December 9, 2011*

**Economics**

Explain how the emergence of the global marketplace has been linked to increased integration of the world’s economies. I think globalisation is involved, how can I structure my answer? Thanks!
*November 3, 2011*

**Economics**

Explain why quotas are more effective than tariffs. Thanks! :)
*November 3, 2011*

**Math- integration**

Find the area bounded by x^(2/3) and x= y^2 in the first quadrant. (I've worked out the x intercepts to be 0 and 1 in the first quadrant, but how would I find the area?) thanks :)
*November 1, 2011*

**Maths : circular motion**

1. A 3 metre piece of string is threaded through a hole in the table. If equal portions of the string are above and below the table, and the top mass of 2kg rotates at 1rev/sec , how fast does the bottom mass of 1kg rotate? (in rev/sec) 2. If, in the above question, the two ...
*October 28, 2011*

**Maths - Circular Motion **

One end of a string of length 1m is attatched to the rim of a 2m radius disc while the other end carries a mass of 5kg. If the tension in the string may not exceed 300N. find the maximum speed w in radians/sec and the corresponding angle of inclination of the string to the ...
*October 28, 2011*

**math**

let x be the number of horses, and y be the number of riders: x + y = 36 ........(1) 4x + 2y = 104 .....(2) Solving simultaneously, (1) x 2 2x + 2y = 72 ....(3) (2) - (3) 2x = 104 - 72 = 32 thus x = 16 When x = 16, [sub into (1)] y = 20 Therefore there are 16 horses and 20 ...
*September 27, 2011*

**biology: genetics**

In Drosophila melanogaster, cut wings (ct) is recessive to normal wings (ct+), sable body (s) is recessive to gray body (s+), and vermilion eyes (v) is recessive to red eyes (v+). All three recessive mutations are X- linked. A female fly with cut wings, sable body, and ...
*July 17, 2011*

**math**

-2(x+5)(x-43)
*April 8, 2011*

**english**

ok :)
*March 10, 2011*

**english**

ok thanks
*March 10, 2011*

**english**

We use wikipedia. Do you know of any other helpful websites????????
*March 10, 2011*

**english**

My question is about sasquatches. I just want to know if they are real. Is there someone who can answer this question??
*March 10, 2011*

**physics**

A baseball mass of 150.0g, is thrown by the pitcher toward the home plate with a velocity of 45.0 m/s. it is hit back at the pitcher with a velocity of 60.0 m/s, what is the average force on the bat, if the ball and bat are in contat for a time of 100.0 ms? What is the change ...
*March 1, 2011*

**vocabulary**

which of these words probably comes from the latin word conducere, meaning to lead together?? complete,control,convince, conduct?
*February 25, 2011*

**chemistry**

Consider the following multistep reaction: C+D-> <-CB (FAST) CD+D->CD2 (SLOW) CD2+D->CD3 (FAST) C+3D->CD3 (OVERALL) Based on the mechanism determine the rate law for the overall reaction??
*February 8, 2011*

**Chemistry**

consider the following reaction mechanism 2A+B->B+C B+D->E+C What is the rate law for step 2 of this reaction?
*February 7, 2011*

**algebra**

cubed square root 16x^2y over cubed square root 2xy^2
*November 8, 2010*

**Chemistry**

To what volume should you dilute 25mL of a 12.0M H2SO4 solution to obtain a 0.170M H2S04 solution?
*September 29, 2010*

**Biology**

What is the advantage of producing single sex gametophytes (heterospory) and what is the advantage of producing a bisexual gametophyte (homospory)?
*September 6, 2010*

**Science**

What physical process is being observed using spectroscopic measurements in Beer's Law experiment?
*September 2, 2010*

**Math**

6eggs in 7days. find the unit rate
*August 30, 2010*

**science**

why did the balance record a decrease in mass during the reaction betwwn iron sulphide and hydrochloric acid?
*August 22, 2010*

**Calculus **

find the area of the region. 2y=4sqrtx , y=3 and 2y+2x=6 ?
*August 17, 2010*

**american government **

Some analysts maintain that the United States is poorly served by a Congress that is often beset by inaction and localism. Supporters of the Congress maintain that the institution is a superior deliberative and representative institution. Which argument is the more persuasive ...
*August 11, 2010*

**Math**

Evaluate can you please show me the steps. -3/4-3/16
*May 5, 2010*

**Algebra 1**

m(squared)-8m+n Find the value on n such that each expression is a perfect square trinomial.
*April 12, 2010*

**Chemistry**

A sample of solid Ca(OH)2 is stirred in water at 30°C until the solution contains as much dissolved Ca(OH)2 as it can hold. A 100.-mL sample of this solution is withdrawn and titrated with 5.00 X 10^-2 M HBr. It requires 48.8 mL of the acid solution for neutralization. ...
*February 17, 2010*

**Math**

Is (-1,5) a solution of each system? X+y=4 x=-1
*January 29, 2010*

**English**

Is the grammar right in this. It's bullet pointed in a resume. Should all those different words be capitalized or lower cassed? Oversee plant operation of Meat Dept, Pantry, Sauce Room, Bakery, Security, Shipping/Receiving and Sanitation
*January 1, 2010*

**Eli whitney**

American inventor Eli Whitney (1765–1825) designed the cotton gin (a machine that separates raw cotton fibers from their seeds) after he visited a Georgia plantation and observed the difficult process of separating seeds from fibers on the cotton boll (flower). Cleaning ...
*December 21, 2009*

**Eli whitney**

First, the cotton balls were put into the top of the machine. Next, you turn the handle, which turns the cotton through the wire teeth that combs out the seeds. Then the cotton is pulled out of the wire teeth and out of the cotton gin.
*December 21, 2009*

**english**

What does it mean when a writer narrative structure is a spiral and what does it mean when a writers narrative structure is webbed?
*December 15, 2009*

**Orgo**

thanks
*November 22, 2009*

**Orgo**

How do I know which cyclohexdiene (?) is more stable? There's one where the double bonds are directly opposite each other (1,4) and another where they are almost next to each other but skip one side (1,3).
*November 22, 2009*

**Chemistry!**

1) does an increase in temperature increase the rate of bothe exothermic and endothermic reactions? 2) is the reaction between sodium thiosulphate and hydrochloric acid self-sustaining? This is for a practical investigation and im battling to find answers..any help greatly ...
*August 27, 2009*

**math**

Find the number of solutions to the equation 2x + 5y = 2005, where x and y are positive integers. Thank u :)
*July 15, 2009*

**maths**

Let X and Y be positive integers such that X^2 + 3X + Y^2 = 404. What is the value of X + Y^3? Find all possible solutions. Thanks! :)
*June 9, 2009*

**maths**

Let ABCD be a square with side legnth 7cm. Another square KLMN is inscribed into ABCD such that its vertices lie on the sides of ABCD. Find the lenghts of parts of ABCD sides which are divided by the vertices of KLMN. If [the area of KLMN]: [area of ABCD] = 25:49
*June 9, 2009*

**maths**

A positive integer n is such that numbers 2n+1 and 3n+1 are perfect squares. Prove that n is divisible by 8. thanks
*June 9, 2009*

**Maths**

How do you find the gradient of a curve??
*May 19, 2009*