# Posts by David

Total # Posts: 2,248

**english**

a letter to your uncle in american asking him to help you pay your school fees for this term.

*May 9, 2016*

**Chemistry**

The reaction of methyl-benzene with HNO3 in the presence of catalyst will provide what main compound?

*May 9, 2016*

**math**

The radius of a circle in increasing at the rate of 0.5cm/s. Find the rate at which the circumference increases if the radius in 5cm.

*May 8, 2016*

**Calculus**

A bucket begins weighing 30 pounds, including the sand it holds. The bucket is to be lifted to the top of a 25 foot tall building by a rope of negligible weight. However, the bucket has a hole in it, and leaks 0.1 pounds of sand each foot it is lifted. Find the work done ...

*May 6, 2016*

**chemistry**

1 mole ----> 24 g ? mole -----> 0.12 moles ( Mg ) = 0.12 / 24 = 0.005 moles of Mg

*May 5, 2016*

**Chemistry**

DrBobb22 Calcule the concentrations of Cd^+2 , [Cd(CN)4^-2] and CN^- at equilibrium, when 0.42 moles of Cd(NO3)2 dissolves in 1 L of 2.50 M NaCN Kf for Cd(CN)4^-2 is 7.1x10^16

*May 5, 2016*

**Chemistry**

I will post again ok?

*May 5, 2016*

**Chemistry**

Kf is 7.1 x 10^16

*May 5, 2016*

**Chemistry**

DrBobb22 Calcule the concentrations of Cd^+2 , [Cd(CN)4^-2] and CN^- at equilibrium, when 0.42 moles of Cd(NO3)2 dissolves in 1 L of 2.50 M NaCN Kf for Cd(CN)4^-2 Help!

*May 5, 2016*

**Chemistry**

Calculate the concentrations of Cd+2 , Cd(CN)4^-2 and CN at equilibrium when dissolvs 0.42 moles of Cd(NO3)2 (2.50 mol/L) Kf for Cd(NO3)2 = 7,1x10^16.

*May 5, 2016*

**Chemistry**

What volume in ml of 0.500 M silver nitrate is required to completely react with 25.0 ml of 1.5 M calcium chloride?

*May 5, 2016*

**Math**

f(x) = cos (1/x) Find the limit as x approaches infinity and find the limit as x approaches negative infinity. Identify all horizontal asymptotes.

*May 4, 2016*

**Math**

f(x) = cos (1/x) Find the limit as x approaches infinity and find the limit as x approaches negative infinity. Identify all horizontal asymptotes.

*May 4, 2016*

**mathematics for accounting**

the question is the formula use in calculating depreciation that is reducing balance method which is (1-n√s/c)×100/1 now we were asked to now make each of n,s,and c in the formula the subject of the formula

*May 4, 2016*

**math**

make each of the following the subject of the formula n,s,c in (1-n√s/c)*100/1

*May 4, 2016*

**Math**

f(x) = tan x / sin x Find the vertical asymptote. Describe its behavior to the left and right of the vertical asymptote.

*May 3, 2016*

**Chemistry**

This is the correct one because you simply just have to do a double replacement reaction. H3PO4 + 3KOH -> K3PO4 + 3 H2O

*May 3, 2016*

**Chemistry**

This is the correct one because you simply just have to do a double replacement reaction. H3PO4 + 3KOH -> K3PO4 + 3 H2O

*May 3, 2016*

**Quantitative Chemistry**

(H: +1, Cl: -1) (Mn: +4, O: -2) --> (Mn: +2, Cl: -1) (H: +1, O: -2) (Cl: 0) So, as you can see the Manganese atoms are clearly being reduced which means that it is gaining electrons, so the charge goes down. You can now eliminate choice A. Next, we can see that the charge ...

*May 3, 2016*

**Geometry**

Find the volume of the large solid without the smaller solid. The solid is a right solid and is not drawn to scale. Round answers to the tenths place.

*May 2, 2016*

**Math**

Thanks sir

*April 30, 2016*

**Math**

A bucket begins weighing 15 pounds, including the sand it holds. The bucket is to be lifted to the top of a 50 foot tall building by a rope of negligible weight. However, the bucket has a hole in it, and leaks 0.1 pounds of sand each foot it is lifted. Find the work done ...

*April 30, 2016*

**Math**

Thanks Damon!

*April 30, 2016*

**Math**

kinematics look easier i can do both ways but will they have different values

*April 30, 2016*

**Math**

its calculus but will kinetatic equations work as well?

*April 30, 2016*

**Chemistry**

Consider the reaction: K2S(aq)+Co(NO3)2(aq)=2KNO3(aq)+CoS(s) what volume of 0.255 M K2S solution is required to completely react with 160 mL of 0.130 M Co(NO3)2?

*April 29, 2016*

**Chemistry**

Thanks!!!

*April 29, 2016*

**History**

The answer is dessert

*April 26, 2016*

**Calculus 2**

Suppose that a spring has a natural length of 25 cm, and that 8 J of work is needed to stretch from a length of 50 cm to 80 cm. How far beyond its natural length will a force of 32 N keep the spring stretched? **I've tried calculating the spring constant ...

*April 25, 2016*

**Government**

Why people who represents special interest group received the name lobbyist ?

*April 25, 2016*

**Programming**

I am having a problem with something. i nead to assing values to parameters from input.dat file without using fscanf. i need to use the terminal like a.out<input.dat>output.out i have a file like this GEN 0.0 2.1351 0.00001 500 o PEND 0.12 0.1 0.15 0.5 0 0.16 0.11 0.8 -0...

*April 24, 2016*

**algebra 2**

Write (21 − 4i) − (16 + 7i) + 28i as a complex number in standard form.

*April 21, 2016*

**Chemistry**

[2.0 mol (-285.91 kJ/mol)] + [1.0 mole (0 kJ/mol)] - [1.0 mole (50.61 kJ/mol)] = ??? I came up with the answer of -622.43 but im not sure what the correct amount of significant figures would be and why? would 0 kj/mol be considered significant making the answer -600? what ...

*April 17, 2016*

**have got a question@sir-damon**

so how can i get the total

*April 17, 2016*

**maths help plz**

A certain number of children are arranged in a circular form,if they are evenly spaced,the 7th child is directly opposite to the 8th child.... how many children are their altogether? thanks

*April 17, 2016*

**History**

Why is the Franco-Prussian War considered an important development in the history of Europe? It was at this time that France reclaimed its military dominance in Europe. It was because of this war that Germany began its military dominance in Europe. The war allowed Prussia to ...

*April 16, 2016*

**History**

Use the following statement by Robert Owen to answer the question below: "...but I know that society may be formed so as to exist without crime, without poverty, with health greatly improved, with little if any misery, and with intelligence and happiness increased a ...

*April 16, 2016*

**Chemistry**

Thank you @DrBob222

*April 15, 2016*

**Chemistry**

Which is more soluble in water, Cl2 or I2?

*April 15, 2016*

**Essay Help**

Have you figured what to do with your comparison essay? I know it is a bit late to help you. In case somebody seeks for the help I want to assure you that you may get the assistance from the company I like. I make the grade thanks to Marvelous essay service.

*April 13, 2016*

**Chemisty**

Well I asked about using phenolphthalein and my teacher said that it was not a good idea. But when I was looking online, I saw some experiments using the amount of gas produced to find the amount of acetic acid in a 20Ml of vinegar in g/ml If you could tell me how this this ...

*April 7, 2016*

**Chemisty**

I was told to find the concentration of acetic acid in vinegar when only using baking soda and common lab equipment. Can someone tell me how Thanks

*April 7, 2016*

**maths help me urgently!!!!!!**

rationalise [1-(2i^2)]/i Plz help show we working so that i can learn

*April 7, 2016*

**Physics 1**

A textbook of mass 1.95 kg rests on a frictionless, horizontal surface. A cord attached to the book passes over a pulley whose diameter is 0.100 m , to a hanging book with mass 3.08 kg . The system is released from rest, and the books are observed to move a distance 1.27 m ...

*April 6, 2016*

**maths polynomial help!!!!**

x^2+2x+1 is a factor of ax^3+ax^2+bx+c then find a b c help!!

*April 6, 2016*

**physics**

Use conservation of energy to determine the angular speed of the spool shown in the figure below after the 3.00 kg bucket has fallen 4.05 m, starting from rest. The light string attached to the bucket is wrapped around the spool and does not slip as it unwinds. the spool, ...

*April 6, 2016*

**physics**

A ball bounces to 34 percent of its original height. *1) What fraction of its mechanical energy is lost each time it bounces? *2) What is the coefficient of restitution of the ball-floor system? - I was able to solve part one and get an answer of .66, but part two I don't ...

*April 5, 2016*

**physics**

i've tried that and it was incorrect. thanks for trying

*April 5, 2016*

**physics**

A ball bounces to 34 percent of its original height. *1) What fraction of its mechanical energy is lost each time it bounces? *2) What is the coefficient of restitution of the ball-floor system? - I was able to solve part one and get an answer of .66, but part two I don't ...

*April 5, 2016*

**trigonomentry out of ideal help ah!crying**

compute.. Cos(1degree)+cos(3degree)+cos(5degree)+...+Cos(179degree) plz show working even an hint can,t help me.Have been do maths alday my brain is fried..Ah thanks

*April 1, 2016*

**MAth**

Lily and rose are playing a game, in the game,each player starts with 0 points and the player with the most points at the end win. Lily gains 5 points two times loses 12 points ,and then gains 3 points. Rose loses 3 points two times,loses 1point,gains6 points another gains7 ...

*March 31, 2016*

**math**

I got it now. 13 combination 1. Thanks

*March 31, 2016*

**math**

@steve, Please I'm not clear with what you mean by 13C1. Thanks

*March 31, 2016*

**math**

Assuming you are listening to your favorite playlist that has 83 country songs, but your mom also added 9 pop. Suppose that shuffle mode is on - a song played is being selected at random (with replacement) from the playlist. Find the probability that, out of the next 13 songs...

*March 31, 2016*

**physics steve or damon help!!!!**

A stone is thrown horizontally from the top of a vertical wall with a velocity of 15m/s hit the horizontal ground at a point 45m from the base of the wall.calculate the height of the wall g=10

*March 28, 2016*

**physics**

Two equally long 12-cm diameter pipelines have the same pressure difference between ends. One carries a ‘Type A’ oil (𝜂 = 0.091 Pa s) and the other a ‘Type B’ oil (𝜂 = 0.064 Pa s). If ‘Type A’ oil flows at 0.14 m3/s, at which rate ...

*March 26, 2016*

**Physics**

A material is formed into a long rod with a square cross section 0.31 cm on each side. When a 100 V voltage is applied across a 16 m length of the rod, a 4.6 A current is carried. What is the resistivity of the material? This is a rectangular wire rather than a cylindrical. I ...

*March 24, 2016*

**maths geomentry help!!!**

the area of a sector PQR is a @rad.and the radius of the of the circle is rcm,the area of the sector is 20cm^2 and the perimeter is 26cm.find r?

*March 22, 2016*

**integration!!help urgently**

what the meaning of that box

*March 21, 2016*

**integration!!help urgently**

integrate:dz/(z^2+1) where z is a complex number.....plz working

*March 21, 2016*

**Discrete Math Help**

1) How would I prove that (n - 1 + 2 C 2) = n + (n C 2) 2) A cafeteria offers 17 types of pizza and 5 types of soda. Bob goes there everyday for lunch, always buying two slices of pizza and one soda. However, he never gets exactly the same thing on two consecutive days (that ...

*March 20, 2016*

**Math**

Determine the (binomial) coefficient. (x^2+3)^12; ax^8 I got 12C8 * (x^2)^4 * (3)^4 which is 40,095*x^16 but my teacher said it was incorrect. A similar problem to it was (x+3)^12; ax^5 where I determined the answer to be 1,732,105*x^5 which was correct.

*March 17, 2016*

**History**

Thx MS. SUE

*March 16, 2016*

**phi 103**

Identify the form of the following argument. Either the Pacers or the Kings will win tonight. The Pacers will win. Therefore, the Kings will not win. a. not a valid form b. disjunctive syllogism c. modus ponens d. hypothetical syllogism e. modus tollens

*March 12, 2016*

**Physics 1**

A 50 kg cannonball hits a war tank vehicle of 12,000 kg that is initially at rest. The cannonball embeds in the tank and both move at the same velocity for 50 cm until they both come to a rest. What is the initial velocity of the cannonball if the coefficient of friction ...

*March 8, 2016*

**Physics 1**

A golf ball of mass 125 g hits a billiards ball of mass 172.5 g that is initially at rest. After the collision, the golf ball moves to the right at a speed of 10 cm/s. The billiards ball moves to the left with a speed of 58 cm/s. (a) What was the velocity of the golf ball ...

*March 8, 2016*

**Physics 2**

Two boxes are connected by a light string that passes over a light, frictionless pulley. One box rests on a frictionless ramp that rises at 30° above the horizontal (see the Figure below), and the system is released from rest. (a) Which way will the 50kg box move, up the ...

*March 4, 2016*

**Physics**

Two boxes are connected by a light string that passes over a light, frictionless pulley. One box rests on a frictionless ramp that rises at 30° above the horizontal (see the Figure below), and the system is released from rest. (a) Which way will the 50kg box move, up the ...

*March 4, 2016*

**Algebra**

A car traveled 60% of the way from town A to town B at an average speed of 50 mph. The car travels at an average speed of "S" mph for the remaining part of the trip. The average speed for the entire trip was 45 mph. What is "S"?

*March 1, 2016*

**MATH**

A PLOT OF RECTANGULAR LAND HAS A WIDTH OF 20 FEET.THE TOTAL SQUARE YARDS ARE 396.WHAT IS THE LENGTH OF THE PLOT

*February 27, 2016*

**science**

a bike weighs 200 n. if it starts from rest and travels 100 m in 5 s undergoing constant acceleration, what net force is causing the acceleration

*February 26, 2016*

**Math**

A sidewalk is 40 m long. each section of the sidewalk is 8 dm long. how many sections of sidewalk are there?

*February 24, 2016*

**engineering science**

A solid cylinder rolls from rest down an incline 6m high without slipping. calculate the linear velocity at the foot of the plane

*February 22, 2016*

**general physics**

A string going over a massless frictionless pulley connects two blocks of masses 5.9 kg and 9.5 kg. the 5.9 kg block lies on a 31 ◦ incline; the coefficient of kinetic friction between the block and the incline is µ = 0.22. The 9.5 kg block is hanging in the air. ...

*February 20, 2016*

**Physics**

Thank You this is what i needed

*February 16, 2016*

**Physics**

A hoop starts from rest at a height 1.8 m above the base of an inclined plane and rolls down under the influence of gravity. What is the linear speed of the hoop's center of mass just as the hoop leaves the incline and rolls onto a horizontal surface? (Neglect friction.) I...

*February 16, 2016*

**life orientation**

Yes

*February 13, 2016*

**General physics**

A 4.6 kg object is subjected to two forces, F~1 = (2.8 N)iˆ+(−3.5 N)jˆ and F~2 = (4 N)iˆ+(−11.5 N)jˆ. The object is at rest at the origin at time t = 0.What is the magnitude of the objects acceleration? -i've tried using the equation ...

*February 10, 2016*

**Algebra**

Lily sold 18 items at the street fair. She sold bracelets for $6 each and necklaces for $5 each for a total of $101. Which system of equations can be used to find b, the number of bracelets she sold, and n, the number of necklaces she sold?

*February 9, 2016*

**Calculus (double integral) PLEASE HELP!**

Evaluate double integral ln((x-y)/(x+y)) dy dx where the double integral region is the triangle with vertices (1,0),(4,3), (4,1). Hint: use a transformation with the Jacobian.

*February 8, 2016*

**Calculus (Jacobian question)**

Evaluate double integral ln((x-y)/(x+y)) dy dx where the double integral region is the triangle with vertices (1,0),(4,3), (4,1). Hint: use a transformation with the Jacobian.

*February 7, 2016*

**Calculus**

Evaluate double integral ln((x-y)/(x+y)) dy dx where the double integral region is the triangle with vertices (1,0),(4,3), (4,1). Hint: use a transformation with the Jacobian.

*February 7, 2016*

**Math**

Thank you! I finally understand!

*February 6, 2016*

**Math**

Given the equations y=16 and y=3. Determine the slope and y-intercept if any exist. I have determined that the slope is 0 for both equations because it is a horizontal line, but I don't know what the y-intercepts are?

*February 6, 2016*

**Algebra**

Given the equations y=16 and y=3. Determine the slope and y-intercept if any exist. I have determined that the slope is 0 for both equations because it is a horizontal line, but I don't know what the y-intercepts are?

*February 6, 2016*

**Economics**

The correct answer should be C. Remember, command economies are related to communism where the government controls everything. So, the government controls the economy, all the land, and they decide what job people get.

*February 2, 2016*

**Math**

In Super Bowl I, the Green Bay Packers defeated the Kansas City chiefs by a score of 35 to 10. The total points came from 13 different scoring plays, which were a combination of touchdowns, extra point kicks, and field goals, worth 6, 1, and 3 points respectively.The same ...

*February 2, 2016*

**Math**

In Super Bowl I, the Green Bay Packers defeated the Kansas City chiefs by a score of 35 to 10. The total points came from 13 different scoring plays, which were a combination of touchdowns, extra point kicks, and field goals, worth 6, 1, and 3 points respectively.The same ...

*February 1, 2016*

**physics2048**

A ball is thrown straight up from the ground with an initial velocity of 43.5 m/s; at the same instant, a ball is dropped from the roof of a building 15.4 m high. After how long will the balls be at the same height? The acceleration of gravity is 10 m/s^2 Answer in units of s...

*January 30, 2016*

**math**

1+1= 001+001=010 =010

*January 28, 2016*

**math**

Alex scores 1\5 of the teams goals in the playoffs. Of those goals, 1/3 of them were scored during a power play. What fraction of the teams playoff goals were scored by Alex on the power play?

*January 22, 2016*

**Chemistry 101**

13

*January 19, 2016*

**Math**

Suppose you rent apartments in a large apartment complex. Currently there are 90 apartments being rented at a rent of $1300 per month. Evidence shows that for every increase of $25 per month in rent, there will be 1 additional unit unrented. (a) U is the number of units rented...

*January 19, 2016*

**Science(physics)**

1.25N

*January 19, 2016*

**Technology**

bri is right!! I got 100%

*January 18, 2016*

**math**

a jucket cost £45 in the "15℅ off "sale. how much did it cost before the sale?

*January 17, 2016*

**Math**

3/11 eleven up on three.

*January 17, 2016*

**chemistry**

1 gm of magnesium is burnt in a closed container which contains 2 l of air at ntp containing 21 percent oxygen by volume find limiting reagent, mass of excess reagent left over, mass of mgo produced, number of mg and oh ion formed by dissolving it with water

*January 14, 2016*

**Math**

Thank you so much Reiny! I finally understand it!

*January 13, 2016*

**Math**

(2+3i)^6 Using Demoirves Theorem. I tried solving it out, but somehow it didn't work for me. (2+3i)^6 r=|z|=square root of 2^2 + 3^2 = square root of 13 z = square root of 13 * (cos____ + isin_______ ) At this point I am stuck, so can someone help me?

*January 13, 2016*