Friday

December 19, 2014

December 19, 2014

Total # Posts: 222

**math**

It is a 4-digit number The tens are double the ones. The thousands are double the tens. The sum of the digits is 19. What number is it?
*December 8, 2014*

**Math**

b_n=(-2)^(n-1)
*November 30, 2014*

**marhs**

A wheel is free to rotate about its fixed axle. A spring with constant k = 290 N/m is attached to one of its spokes a distance r = 23 cm from the axle, as shown in the figure. (a) Assuming that the wheel is a hoop of mass m = 490 g and radius R = 0.97 m, what is the angular ...
*November 15, 2014*

**math**

f(x)= 1/3x^5 + x^-2 + 3, then f'''(x) is.. I got f'''(x)= 20x^2-24x^-5 Can you tell me if I got this right
*November 11, 2014*

**I need checking**

Whats the 2nd derivative of 4xsecx I got 4secxtanx+8xsecxtan^2x
*November 11, 2014*

**Math**

Whats the 2nd derivative of 4xsecx I got 4secxtanx+8xsecxtan^2x
*November 11, 2014*

**Derivatives check**

find the 2nd derivative of y= 1/x +cosxsinx I got 2/x^3 - 2cosxsinx is this right or did I get this wrong
*November 11, 2014*

**Information and communication technology**

please tell me new ideas regarding information and communication technology that have not yet used in daily life..
*November 7, 2014*

**Physics**

Three particles A, B, C start from the origin from the same time, A with velocity a along x-axis, B with velocity b along y-axis, C with velocity c in xy plane along a line x=y. What should be the magnitude of c so that they always remain collinear is (a). (a+b)/2 (b). √...
*November 6, 2014*

**physics**

A 80-kg man stands on a bathroom scale inside an elevator. (a) The elevator accelerates upward from rest at a rate of 1.40 m/s2 for 1.50 s. What does the scale read during this 1.50 s interval? N (b) The elevator continues upward at constant velocity for 8.50 s. What does the ...
*October 14, 2014*

**physics**

The figure below shows Superhero hanging motionless from a rope, with Trusty Sidekick hanging below him. Superhero's mass is 89.0 kg, while Trusty Sidekick's is 58.0kg, and the mass of the rope is negligible. (a) Find the tension in the rope at a point between ...
*October 14, 2014*

**English**

Sons By John Updilike How is the tone of the narrator?
*October 14, 2014*

**Physics**

I need help setting up this problem. A tennis player serves a tennis ball such that it is moving horizontally when it leaves the racquet. When the ball travels a horizontal distance of 19 m, it has dropped 58 cm from its original height when it left the racquet. What was the ...
*September 30, 2014*

**Physics**

I need help setting up this problem. While standing on the roof of a building, a child tosses a tennis ball with an initial speed of 15 m/s at an angle of 20° below the horizontal. The ball lands on the ground 2.8 s later. How tall is the building? Thank you.
*September 30, 2014*

**Physics Repost**

I need help setting up this problem. A tennis player serves a tennis ball such that it is moving horizontally when it leaves the racquet. When the ball travels a horizontal distance of 19 m, it has dropped 58 cm from its original height when it left the racquet. What was the ...
*September 30, 2014*

**Physics Repost**

I need help setting up this problem. While standing on the roof of a building, a child tosses a tennis ball with an initial speed of 15 m/s at an angle of 20° below the horizontal. The ball lands on the ground 2.8 s later. How tall is the building? Thank you.
*September 30, 2014*

**Physics**

I need help setting up this problem. While standing on the roof of a building, a child tosses a tennis ball with an initial speed of 15 m/s at an angle of 20° below the horizontal. The ball lands on the ground 2.8 s later. How tall is the building? Thank you.
*September 30, 2014*

**Physics**

I need help setting up this problem. A tennis player serves a tennis ball such that it is moving horizontally when it leaves the racquet. When the ball travels a horizontal distance of 19 m, it has dropped 58 cm from its original height when it left the racquet. What was the ...
*September 30, 2014*

**physics**

I need help attacking this problem A steel ball is dropped onto a hard floor from a height of 1.95 m and rebounds to a height of 1.87 m (assume positive direction is upward) A. Caculate it's velocity just before it strikes the floor B. calculate it's velocity just ...
*September 21, 2014*

**Physics**

A steel ball is dropped onto a hard floor from a height of 1.95 m and rebounds to a height of 1.87 m (assume positive direction is upward) A. Caculate it's velocity just before it strikes the floor B. calculate it's velocity just after it leaves the floor on its way ...
*September 20, 2014*

**Physics**

A steel ball is dropped onto a hard floor from a height of 1.95 m and rebounds to a height of 1.87 m (assume positive direction is upward) A. Caculate it's velocity just before it strikes the floor B. calculate it's velocity just after it leaves the floor on its way ...
*September 18, 2014*

**maths**

calculate the total surface area of a solid cone of slant height 10cm. use the value 3.14 for radius
*May 2, 2014*

**physics-impulse**

A tennis ball of mass m = 0.068kg and speed v = 21m/s strikes a wall at a 45∘ angle and rebounds with the same speed at 45 What is the magnitude of the impulse given to the ball?
*March 14, 2014*

**physics**

A child in a boat throws a 5.15-kg package out horizontally with a speed of 10.0 m/s. The mass of the child is 24.2kg and the mass of the boat is 33.2kg . Calculate the velocity of the boat immediately after, assuming it was initially at rest.
*March 14, 2014*

**ordering numbers( math) please help**

if you take five tests and come out with your grades. order these numbers from least to greatest 76% 8/10 90% 17/20 83% then find the average of the five quizzes
*February 10, 2014*

**Math**

Jacob is baking chocolate chips cookies. the recipe uses 3/4 cups of sugar. Jacob wants to make one half of a batch. how many cups of sugar does he need? 1/4
*January 30, 2014*

**Math**

Jacob is baking chocolate chips cookies. the recipe uses 3/4 cups of sugar. Jacob wants to make one half of a batch. how many cups of sugar does he need? 2/3
*January 30, 2014*

**health **

the key to using a pedometer to meet the physical activity guidlines for americans is to?
*January 4, 2014*

**science@@@@**

how to make a model for scince fair for purification of smoke coming out of chimneys? And how this purified smoke can be used for useful purposes? Does smoke contain moisture?
*October 20, 2013*

**math**

A street light is mounted at the top of a 19-ft-tall pole. A man 5.5 feet tall walks away from the pole with a speed of 14 ft/s along a straight path. How fast is the tip of his shadow moving when he is 100 feet from the pole?
*October 18, 2013*

**Finance**

Consider the following income statement and answer the questions that follow: Sales(100 units) $200 Variable costs (.80each) 80 Fixed costs 20 EBIT 100 Interest expense 30 EBT 70 Income tax 24 Net income 46 a)what is the firm's Breakeven Point in units? b)draw a breakeven ...
*October 8, 2013*

**scince@@@**

i have to make a model for science fair. Any new development!. So please give me only idea that which new development can be possible with the help of eddy currents or induction of emf...........
*September 28, 2013*

**Physics**

In a physics study group, a friend says in a profound tone that light is the only thing we can see. After a few laughs, your friend goes on to say that light is produced by the connection between electricity and magnetism. Is your friend correct? My responds is that my friend ...
*August 24, 2013*

**computer**

write the programing for following 1 2 3 4 5 6 7 8 9 10 10 9 8 7 6 5 4 3 2 1 1 1 2 1 2 3 1 2 3 4 1 1 1 1 1 2 2 2 2 2 3 3 3 3 3 4 4 4 4 4
*August 16, 2013*

**physics £££**

according to einstein's mass energy relation M= m'/root[1-(v^2/c^2)] Where M is mass of particle when it moves with velocity 'v' And m' is its initial mass. When particle moves with velocity of light i.e. When 'v=c' then M= m'/0 =infinity i.e. ...
*August 11, 2013*

**maths**

prove that 4cos36+cot15/2=1+4+9+16+25+36,ifcot15/2 is1+cos15/+sin15
*July 26, 2013*

**maths**

an amount of Rs 5000 is put into three/investments at the rate of interest of 6%, 7%, 8% per annum respectively; the total annual income is Rs 35800. If the combined income from first two investments is Rs 70 more than the income from the third. Find amount of each installment...
*July 1, 2013*

**physics**

how to show with the help of a model that resistivity of a conductor increases with increase in temperature?
*June 27, 2013*

**chemistry**

why acceleration at any instant does not velocity at any instant?
*June 23, 2013*

**chemistry**

show that accelration at any instant does not depend upon velocity at any instant?
*June 23, 2013*

**chemistry**

by using brain
*June 23, 2013*

**chemistry**

1)How can you determine average velocity from displacement time graph?
*June 23, 2013*

**physics**

prove that average velocity of particle over an interval of time is either smaller than or equal to average speed of particle over same interval?
*June 23, 2013*

**physics**

please give me some idea for making a working model based on optics. Like combination of light and lenses, spectrum etc......& how can i make a working model with the use of contact lenses....
*June 18, 2013*

**physics**

1.descibe the construction and working of machine used to generate high voltage? 2.draw electric lines between the plates of a parallel plate capacitor with 1(air) and 2(dielectric) as a medium? 3.near the surface of earth the field is about 100V/m. why do we then not ...
*June 10, 2013*

**physics**

how does the total energy stored in a capacitor change, when the medium of air is replaced by a medium of dielectric constaant K? Explain.
*June 10, 2013*

**chemistry**

what does 1M solution of sugar stands for?
*June 7, 2013*

**chemistry**

1.what is the advantage of heating gellium semi-conductor with sites or gold instruct of indium and boron? 2.why co-ordination number of 12 is not found in ionic crystals? 3.what kind of symmetry is exhibited by a match box?
*June 7, 2013*

**trigonometry**

sine is function 1/2cos^-1 is its angle. so i can convert cos^-1 into sin^-1 but can i cancel this with sin because there is (1/2).
*June 4, 2013*

**trigonometry**

1.if 2^x+2^y=2^(x+y) then dy/dx is equal to what? 2.If x.root(1+y)+y.root(1+x)=0 then dy/dx is equal to what? 3.Sin[(1/2)cos^-1(4/5)] is equal to what? 4.check the continuity of function f(x)=2x+3 at x=1. 5.check the continuity of the function F(x)={e^x - 1 -x ; x not equal to...
*June 4, 2013*

**mathematics**

1.)Sin^-1(x)+Sin^-1(y)+Sin^-1(z)= pie Prove that X.root(1-y^2)+y.root(1-x^2)+z.root(1-z^2)=2xyz 2.)tan^-1(yz/xr)+tan^-1(zx/yr)+tan^-1(xy/zr)=pie/4 Prove that x^2+y^2+z^2=r^2 Tomorrow is my exam.please give me answer as soon as possible.
*May 23, 2013*

**science**

there is technology day celebration in our school. I have to give a speech on a new technology that has developed recently and very rarely known. Please give me some ideas.
*May 8, 2013*

**physics**

I've done a and b, but I can't figure c out. Do I use G=6.67e-11?
*April 8, 2013*

**Science**

A Family travels 200 km in two hours and 20 min .then they stop to eat lunch.After lunch they travel 300 km In Two 3 Hours and 40min.What is the average speed during the entire trip?
*April 7, 2013*

**maths**

a matrix X has a+b rows and a+2 columns while the matrix Y has b+1 rows and a+3 columns. both matrices XY and YX exist. find a and b. can you say XY and YX sre of same type? are they equal?
*April 4, 2013*

**maths**

a trust fund has rs30000 that must be invested in two diferent types of bonds.the first bond pays 5% and second 7% interest per year. using matrix multiplication determine how to divide rs 30000 among two types of bonds if the trust must obtain na annual total interest of (a)...
*April 4, 2013*

**physics**

a ball rolling on oa inclined plane dors so with constant acceleration. One ball, A, is released from rest on th etop of an inclined plane 18m long to reach the bottom 3s later. At the same time as A is released, another ball, B, is projected up the same plane with a certain ...
*March 24, 2013*

**Chemistry**

Thank you so much!
*March 4, 2013*

**Chemistry**

A buffer consists of 0.16 M KHCO3 and 0.39 M K2CO3. Carbonic acid is a diprotic acid with Ka1 = 4.5 10-7 and Ka2 = 4.7 10-11. (a) Which Ka value is more important to this buffer? Ka1 Ka2 I don't understand this one at all. How do I determine which Ka value is more ...
*March 4, 2013*

**Chemistry**

I have no idea why I was having such a hard time with that one. Thank you so much for your help.
*March 4, 2013*

**Chemistry**

Yeah, I got (a). The answer was 7.53. But when I try to solve (d), I keep getting the wrong answer. I subtracted the moles of NaOH from the acid and added the moles to the base. Then I did Ka = (x*([NaClO]+x))/([HClO - x) and then I found the pH. I got 8.07, but it was wrong.
*March 4, 2013*

**Chemistry**

An industrial chemist studying bleaching and sterilizing prepares several hypochlorite buffers. Find the pH of the following buffers. (a) 0.090 M HClO and 0.090 M NaClO (b) 0.090 M HClO and 0.135 M NaClO (c) 0.135 M HClO and 0.090 M NaClO (d) One liter of the solution in part...
*March 4, 2013*

**Chemistry**

Find the pH of a buffer that consists of 0.82 M methylamin (CH3NH2) and 0.71 M CH3NH3Cl (pKb of methylamine (CH3NH2) = 3.35.) I keep getting 3.41, but it says that it's wrong...
*March 3, 2013*

**Chemistry**

Calculate the pH of 0.215 M carbonic acid (H2CO3). (HINT: do NOT worry about the second H+ in this acid!) How would I solve this?
*March 3, 2013*

**physics**

if the angular speed of earth becomes 17times its present value what will be the 1.effect on a body on the equator of earth? it will be A. Heavier than present value B.lighter than present value C.weightless And also what is the reason? 2.a girl sitting on a swing stands up. ...
*March 1, 2013*

**physics**

if the angular speed of earth becomes 17times its present value what will be the 1.effect on a body on the equator of earth? it will be A. Heavier than present value B.lighter than present value C.weightless And also what is the reason? 2.a girl sitting on a swing stands up. ...
*March 1, 2013*

**Data mining**

2. AllElectronics caries 1000 products, P1, … P1000. Consider customers Ada, Bob, and Cathy such that Ada and Bob purchase three products in common, P1, P2, and P3. For the other 997 products, Ada and Bob independently purchase seven of them randomly. Cathy purchases 10 ...
*February 20, 2013*

**science**

i have to prepare a new technology based model for science fair that has been rarely known. Is there any different technology in america or england that is rarely known?
*February 15, 2013*

**MATHS GEOMETRY!!! URGENT PLEASE. **

A triangle has side lengths 10,17 and 21cm. Find the length of the shortest altitude. And please show working out to help me understand.
*February 15, 2013*

**physics**

sound waves travel faster in humidity than in dry air. But as temperature increases the velocity of sound also increases. So sound travels faaster in hot day than in winter. But during winter there is also presence of humidity in fog. Why doesn't sound travel faster in ...
*February 3, 2013*

**Physics**

0.88cm; depth dependence. listen to your prof.
*January 18, 2013*

**physics**

what is the refrevtion of waves? And what are the laws'of refraction? Also about phase change.
*January 13, 2013*

**physics**

1. What are the examples of supersonic waves? 2. What is match cone, match no? 3. Define echo? 4. What is the effect of frequency on the velocity of sound in a gas? 5. Mathematical expression of beats. ''based on wave motion''
*January 13, 2013*

**Interpersonal Communications**

Imagine that you are hosting a group of exchange students next term. You are responsible for welcoming the students to campus and acquainting the students with life on campus socially as well as academically
*December 18, 2012*

**Algebra**

The number is 14 more then the number to the sum of 30
*December 2, 2012*

**maths**

i tried this way but answer not coming..... :/ ans is 0.25
*November 24, 2012*

**maths**

a circular ink-blot grows at a rate of 2 sq cm per second. find the rate at which the radius is increasing after (28/11)seconds.
*November 24, 2012*

**Math**

A 2.5 ton truck stops and a 1300 pound car slams the brakes and skids 26 feet and hits the truck at 40 mph pushing the truck a foots length. how fast was the 1300 pound car traveling?
*November 7, 2012*

**history**

how are longhouses and present day homes alike '
*November 6, 2012*

**mathematics**

A farmer buys a tracter for Rs 120000. he pays Rs 60000 cash and agrees to pay the balance in annual installments of Rs 5000 plus 12% interest on the unpaid amount. what will the tracter cost him?
*November 4, 2012*

**Science**

2. Contrast the metric units of distance, time, and speed. Describe the relationship between them.
*October 23, 2012*

**physics**

A 2100 car starts from rest at the top of a 5.0m long driveway that is sloped at 20 degrees with the horizontal. If an average friction force of 4000N impedes the motion find the speed of the car at the bottom of the driveway.
*October 16, 2012*

**physics**

how can we collect sound energy from outside? then it can be converted into electricity with the help of transducer. Have to prepare a model on this. Please earlier.
*October 9, 2012*

**busines ethics and starting a small business**

I need exam answers to 25 questions that are on the the above college subject exam.
*October 4, 2012*

**chemistry**

density= mass/ volume
*October 1, 2012*

**chemistry**

5H2O stands for the dehydration of copper sulphate.it shows that copper sulphate solution is hydrated.
*October 1, 2012*

**mathematics **

what is the range of the function f(x)=1/root(|x|-x) and its domain.
*September 23, 2012*

**Thinking Mathematically**

solve A Flag Pole Has A Height Of 16 Yards. It Will Be Supported By Three Cables, Each Of Which Is Attached To The Flagpole At A Point 4 Yards Below The Top Of The Pole And Attached To The Ground At A Pole. Find the total number of feet of cable that will be required
*September 23, 2012*

**mathematics **

if [x] denotes the integral part of x, then what is the solution set of the equation [x]^2 -5[x]+6=0
*September 22, 2012*

**mathematics **

what is the domain and range of the function F(x)= 1/1-2cosx
*September 22, 2012*

**mathematics **

what is the domain of the function f(x)= 1/root([x]^2-[x]-6)
*September 22, 2012*

**mathematics**

What is the domain of the functions f(x)= 1/root(x+|x|) f(x)= x|x|
*September 22, 2012*

**math**

Kate is saving to take an SAT Prep course that costs $350 and saved $180 and she adds $17 to her savings each week. How many more weeks must she save to be able to afford the course? Need the answer right now!
*September 21, 2012*

**physics**

what is the graph of potential energy and kinetic energy against distance?
*September 21, 2012*

**mathematics**

what is the square and square root of zero
*September 21, 2012*

**physics**

what is time paradox and time dillation?
*September 20, 2012*

**physics**

list the contact and non contact forces in mathematics. What is the cold welding?
*September 20, 2012*

**mathematics**

how many liters of water will have to be added to 1125 liters of 45% solution of acid so that the resulting mixture will contain more than 25% but less than 30% acid content.
*September 20, 2012*

**mathematics**

in triangle abc if acosA= bcosB then how to prove the triangle is isosceles or right angled
*September 20, 2012*

**mathematics**

what is the domain of the function f(x)=1/root[2x-3]
*September 20, 2012*