Friday

March 27, 2015

March 27, 2015

Total # Posts: 135

**Math**

Hi I'm having a bit of trouble if anyone is able to help, thanks! Using the substitution u =1-2t^2, show that A = -1/4 ∫_1^(-7)▒e^u du
*March 21, 2015*

**math**

about powers and roots
*February 20, 2015*

**math**

The dissipation of heat through a composite material of width w centimetres can be modelled by the function f(w) = 10/w - 0.77ln(w) – 3.2 You are required to find the width of material that will prevent any heat dissipation. - I understand f(w)= 0, but I'm unsure of ...
*February 15, 2015*

**Physics**

On June 9, 1988, Sergei Bubka broke the world pole-vaulting record for the 8th time in four years by attaining a height of 6.14 m. How long did it take Bubka to return to the ground from the highest part of his vault?
*October 14, 2014*

**Organic Chem Help**

Can someone explain how crystallization works to produce a product that is purer than the input material. Thank you!
*September 23, 2014*

**Math**

the larger angles of a rhombus are twice the smaller angle of the rhombus. if the shorter diagonal is 20, find the perimeter of the rhombus
*December 10, 2013*

**Hypothesis Test**

A test of hypothesis is performed to determine whether the proportion of Montrealers (population 1) who want the decriminalization of marijuana is greater than the proportion of Torontonians (population 2) who want decriminalization of marijuana. A random sample of 120 ...
*November 16, 2013*

**American history**

The religion that is sometimes called Central America is actually apart of what continent.?
*September 23, 2013*

**MGMT303**

1. (TCO 2) Organizations have both an internal and an external environment. Describe the general environment and give at least one specific example of each dimension, other than the examples given in the text and in the lectures
*August 29, 2013*

**physics**

A star rotates in a circular orbit about the center of its galaxy. The radius of the orbit is 4.4 x 1020 m, and the angular speed of the star is 7.3 x 10-15 rad/s. How long (in years) does it take for the star to make one revolution around the center?
*July 16, 2013*

**physics**

In the figure the man hanging upside down is holding a partner who weighs 535 N. Assume that the partner moves on a circle that has a radius of 6.50 m. At a swinging speed of 3.75 m/s, what force must the man apply to his partner in the straight-down position?
*July 10, 2013*

**physics**

A 17-kg sled is being pulled along the horizontal snow-covered ground by a horizontal force of 29 N. Starting from rest, the sled attains a speed of 2.1 m/s in 9.6 m. Find the coefficient of kinetic friction between the runners of the sled and the snow.
*July 8, 2013*

**ECONOMICS**

WHAT ARE WELFARE PAYEMENTS OR CONSUMERS SUBSIDIES
*May 19, 2013*

**math**

A stadium is divided into 8 sections. Each section has 72 rows and each row contains 25 seats. How many seats are in the stadium.
*May 2, 2013*

**Pharmacy**

You have a 10 percent solution and your wanting to treat a patient weighing 4.5 pounds and the dose is 5mg/kg/ml. What is the dose?
*May 2, 2013*

**Calculus**

Use the limit process to find the area of the region between the graph of the function and the x-axis over the indicated interval. Sketch the region. y=2x-x^(3), [1,3]
*April 26, 2013*

**Calculus**

On the moon, the acceleration due to gravity is -1.6 meters per second per second. A stone is dropped from a cliff on the moon and hits hits the surface of the moon 20 seconds later. How far did it fall? What was its velocity at impact?
*April 26, 2013*

**Life orientations**

Discuss 5 impacts due to lack of infrastructure
*April 17, 2013*

**economics**

WHAT ARE WELFARE PAYMENTS OR CONSUMERS SUBSIDIES
*April 5, 2013*

**Life orientation**

Five practices that are in Contravention of the Basic conditions of employment Act
*March 10, 2013*

**math**

a box contain 60 oranges.3/5 of the oranges were equally shared among 4 boys.how many oranges did each boy received.
*February 9, 2013*

**Math**

Tiles is 2000cm bt its ans is wrong
*February 6, 2013*

**Math**

In evening my test plz help me to solve it A room length 3m,20m wide and 6m height. Find the floor is to be tiled.if each tile measures 60cm*50cm,find the no. Of tiles required.
*February 6, 2013*

**Math**

Bt its ans 6166.16cm^3
*February 6, 2013*

**Math**

The cross section of a pipe of length 49cm.the thicknes of the pipe is 1cm4mm and the outer diameter is 30cm.find the volume of the pipe.
*February 6, 2013*

**Math**

Water is poured into cuboidal container at the rate of 80liter per min. If the volume of container is 144m^3,find the no. Of hours it takes to fill the reservior.
*February 5, 2013*

**Math**

Plz help me
*February 5, 2013*

**Math**

Bt its ans is 1816.32cm^2
*February 5, 2013*

**Math**

A cylindrical tube is open at both ends.the internal diameter tube 10.4cm and its length is 25cm. If the thickness of the tube 8mm everywhere,find the total surface of area of the tube.
*February 5, 2013*

**Math**

A box measures 60cm*52cm*40cm.find the area of the cardboards required to make 280 such boxes.
*February 5, 2013*

**Math**

Thank you
*February 5, 2013*

**Math**

The radii of two cylinders 3:2 and height 7:4.find the ratios of their curved surface area.
*February 5, 2013*

**Math**

Please tell me how to solve it
*January 31, 2013*

**Math**

This is math qustn plz help me to solve it bcz tmrw my test soreply soon as soon A box measures 60cm*52cm*40cm.find the area of the cardboards required to make 280 such boxes.
*January 31, 2013*

**Math**

Thanx..
*January 31, 2013*

**Math**

This is math qustn plz help me to solve it bcz tmrw my test soreply soon as soon A box measures 60cm*52cm*40cm.find the area of the cardboards required to make 280 such boxes.
*January 31, 2013*

**chemistry**

Elemental zinc will react with acid to evolve hydrogen gas. This is a redox reaction. Write a balanced molecular equation for the reaction of zinc and hydrochloric acid, showing the coefficents and the phases of all reactants and products. Below is an example of the form of ...
*January 16, 2013*

**chem**

I2 + 5 Cl2 + 6 H2O 2 HIO3 + 10 HCl What is the reducing agent? In your answer give the element symbol and oxidation state.
*January 15, 2013*

**chemistry**

balance: Al2(CO3)3 --> Al2O3 + CO2 i dont know how to do the reactant side so i can figure out the product side...
*January 9, 2013*

**math**

started with= 5 min quarter= 75 min dime = 30 min nickle= 15 min add all the minutes then add to 9:00 am
*January 7, 2013*

**chemistry HWK MAKES NO SENSE**

Thank you!
*January 7, 2013*

**chemistry HWK MAKES NO SENSE **

balance: H3PO4 + Mg(OH)2 → Mg3(PO4)2 + H2O
*January 7, 2013*

**chem **

what is the number of moles of manganese (II) iodide in a sample whose mass is 650 g?
*December 18, 2012*

**math exam tommrow review**

-15p+6 solve for p? -15p+6=0 so 15p=6 p=6/15 or 2/5
*December 18, 2012*

**physics**

A 500N force is applied to a 25 kg block and accelerates it at 15 m/s^2. What is the force of friction?
*November 26, 2012*

**science**

A reaction took place between a magnesium and florine in a large empty container if attraction and repulsive between these atom are equal at a distance of 0.001*10^-10m, calculate the couloumbic force between two atoms.
*October 24, 2012*

**Chemistry (Insulated Vessel, temperature and vol.)**

Insulated vessel has two compartments separated by a membrane. One side is 1 kg of steam at 400 C and 200 bar. The other side is evacuated. The membrane ruptures filling the entire volume. The final pressure is 100 bar. Determine the final temperature of the steam and the ...
*October 2, 2012*

**Chemistry (Internal Energy)**

5 kg of steam contained within a piston-cylinder assembly undergoes an expansion from state 1, where the specific internal energy U(1) is = 2710 [kJ/kg] to state 2, where U(2) = 2660 [kJ/kg]. During the process, there is heat transfer to the steam with a magnitude of 80 [kJ]. ...
*October 2, 2012*

**physics**

Calculate the power required of a 1190 kg car as it climbs a 11° hill at a steady 103 km h-1. The total friction and air resistance is 700 N. Answer in kW, to the nearest whole number.
*September 29, 2012*

**physics**

A skier travelling at 14 m s-1 reaches the foot of a steady upward 14° incline and glides 21 m along this slope before coming to rest. What was the average coefficient of friction?
*September 29, 2012*

**physics**

Total mechanical energy of a flying rubber ball is 2000 J. It has a velocity of 151 ms-1 and is 3.1 m above the ground. Find the mass of the ball. (2dp)
*September 29, 2012*

**physics**

A boy is sledding down a slope that is inclined at 30.0° with respect to the horizontal. A moderate wind is aiding the motion by providing a steady force of 108 N that is parallel to the motion of the sled. The combined mass of the boy and sled is 53.6 kg, and the ...
*September 24, 2012*

**science**

how many seconds will it take for a saterllite to travel 450 km at rate of 120 m/s?
*September 10, 2012*

**Chem-E / Chemistry**

Calculate the rate of heat required to bring 1.80mol/hr of HBr gas from 37.0 C to 434.0C at atmospheric pressure (Heat capacity of HBr is described by eq.) Cp (kJ/mol * C) = a + bT + cT^2 + dt^3 T is in C and HBr - a = 2.910x10^-2, b= -2.27x10^-7, c= 9.887x10^-9, and d= -4....
*August 15, 2012*

**Chemstry**

Dry air is bubbled through 25 litres of water at a rate of 15 litres (STP)/min. The air leaving the liquid is saturated with water at 25 degrees celcius and 1.5 atm. How long it will take for all of the water to vaporize.
*August 5, 2012*

**Chemistry**

Find the volume, in L, of 100g gas mixture containing 10.0 mol% hydrogen in nitrogen at 30.0C and 5.00 atm. Use the avg molecular wt. what is the molar concentration of hydrogen, in mol/L, in the gas mixture? what is the average mass denisity in g/L
*July 26, 2012*

**Chemistry**

semibatch reaction: C6H6(l) +Cl2(g) ==> C6H5Cl(l) + HCl(g) C6H5(l) + Cl2(g) ==> C6H4Cl2(l) + HCl(g) C6H4Cl2(l) + Cl2(g) ==> C6H3Cl3(l) + HCl(g) \reactor contained 11.0 mole of benzene and a product mixture in which the amt of mono-chlorobenzene was 3x the amt of ...
*July 11, 2012*

**Chemstry**

For the reaction A(g) + B(g) <==> C(g) + D(g) the equilibrium constant K is defined as K = Y(sub y) * Y(sub D) / (Y (sub A) * Y(sub b)) where y is the molar fraction of the gas phase of a species At 620.00 K, the equilibrium constant is 1.100. Suppose the feed to a ...
*July 11, 2012*

**Chemistry**

Distillation Scale up: In an experiment 100 lb-mol of 47 lb-mol % ethanol, 53 lb mol % water sol'n is fed into distillation column and separated into two streams: 100lb-mol 0.470 lb-mol ethanol 0.530 lb-mol water goes to: steam 1: 17 lb-mol 0.890 lb-mol Ethanol 0.110 lb-...
*July 7, 2012*

**math**

ralph would like to make a spinner with three diffrent colored regions so that a person would expect to spin the first color half the time,the second color one-third of the time,and the third color one-fourth of the time.is it possibe to make a spinner?Explain
*May 21, 2012*

**Life orientation**

10-15 lines discuss 5 ways in which the human or environmental problem impacts on the community.
*April 21, 2012*

**physics**

Phy 124 – Chapter 22 Problems 1. Consider the following. A spot on a boat is 2.5 m above the water, and the light strikes the water at a point that is 8.0 m horizontally displaced from the spotlight. The depth of the water is 4.0 m. Determine the distance d, which locates...
*March 22, 2012*

**equation**

the smallest 3 consecutive integers is added to twice the largest , the result so obtained is fifteen less than four times the middle integer. find the integers
*March 8, 2012*

**math**

the distance between 2 station A and B is 230 km .two car start simultaneously from A and B in the opposite directions and the distance between them after 3 houra is 20 km. If the speed of one car is less than that of the other by 10 km per hour, find the speed of each cars. (...
*March 8, 2012*

**Calculus**

Greetings, This is a question about selecting courses for my semester. I was planning to take Calculus 3 (Mostly 3-Dimensional topics involving calculus) and a C++ programing course. If you have heard of these courses, can you please tell me your thoughts about me taking these...
*January 3, 2012*

**Linear Algebra**

Let v1= (1,1,2,1) v2= (0,1,3,3) v3= (1,-1,-4,-5) v4= (1,0,-2,-4) a) Let U=span{v1,v2,v3,v4}. Find the dimension of U b) Is span {v1,v2,v3,v4}=R4? c) Find a basis for U Very Much Appreciated!!!
*December 14, 2011*

**Linear Algebra**

A test Question: Find the parametric equations of the line through the origin that is orthogonal to the plane 2x+4y-z=0
*December 14, 2011*

**Electricity and Magnetism**

This was actually a test question: Additional Information: This question is based on the Hall effect in a wire. Question: I want you to build a magnetic feild sensor. You have all the properties of the materials and the dimentions of the sensor. a) derive a formula for a ...
*November 27, 2011*

**Linear Algebra**

Find the basis for the following vector space. Please state the dimension of the vector space. S consists of all x in R3 such that x is orthogonal to n=(2,3,2)
*November 20, 2011*

**linear math**

Let u=(2,0,k,-1) v=(-4,0,-3,2) and w= (0,1,0,0). Each answer must be justified(there is no answer where k=nothing) a) find all values of k, (if any) for which u is orthogonal to v b) Find all values of k (if any) for which the set {u,v,w} is linearly independent. Find all ...
*November 20, 2011*

**world history**

. With respect to human rights issues in Southeast Asia, which statement is most accurate? A. The leaders of the Khmer Rouge fled from Cambodia after 1979. B. Chinese merchants living in Cambodia and elsewhere have carried out vendettas against hill tribes. C. The Khmer Rouge ...
*November 15, 2011*

**Math**

The length and width of a rectangle are (x+4) cm and x cm respectively. Write down expressions for: A. The perimeter of the rectangle B. The length of the side of a square with the same perimeter If the sum of the areas of the square and the rectangle is 94 cm^2 , find x. ...
*October 23, 2011*

**Biology**

Why (in detail please) in the carboxypeptidase mechanism, the weak bonds between an enzyme and a substrate will stretch the peptide bond of the substrate which lowers the bond energy? I just want to know why in detail this happens... Thank you.
*October 9, 2011*

**maths**

no worry found the solution to be 200000((t-7/10)^2+1/100) first by multiplying out as above to get 200000t^2-280000t+100000 then taking out the factor of 200000 to get 200000(t^2-7/5t+1/2) then using the formula x^2+2px=(x+p)^2-p^2 to get 200000((t-7/10)^2-49/100+1/2) ...
*May 30, 2011*

**maths**

(400t-300)(400t-300)+(200t-100)(200t-100) complete the square showing all steps
*May 30, 2011*

**Social Studies**

why greater responsibility is placed on the husband in marriage
*May 18, 2011*

**Quantum Physics**

I dont understand why you've used 4 pi in your answer, i assume your rearranged the uncertainty principle equation for delta Px, but isnt the reduced plancks constant h/ 2pi instead of 4pi ?
*May 18, 2011*

**discreet math**

verify that f(n) = 1 + 2 + 4 + 8+..+ 2^n has order 2^n
*May 1, 2011*

**LIfe orientation**

I think the community will encountor many problems due to substance abuse
*April 26, 2011*

**Physics 30**

I see now that my question was already answered.
*January 25, 2011*

**Physics 30**

It takes a plane flying at 150 km/h 3.0 minutes to circle around a cloud at an altitude of 3000m. What is the diameter of the cloud?
*January 25, 2011*

**Physics HELP! QUICK!**

So does that mean you can just use friction force without resolving it into its components, and so what you use in you equation would be: M V^2/R = M g sin A - M g cosA*mu (This is what you did in the previous example) So did you basically just ignore the vertical component of...
*December 22, 2010*

**Physics HELP! QUICK!**

A banked circular highway curve is designed for traffic moving at 55 km/h. The radius of the curve is 220 m. Traffic is moving along the highway at 38 km/h on a rainy day. What is the minimum coefficient of friction between tires and road that will allow cars to take the turn ...
*December 22, 2010*

**English**

Hey "drwls" can you explain to me how you solved a previous physics question that you answered? It's for the following question below, and it's already posted on here. Unfortunately, it didn't allow me to post the link to it, so you may have to search for...
*December 22, 2010*

**English lit**

Alright thank's!
*December 3, 2010*

**English lit**

Who would have thought...eheh last week I had a literature exam about ''The Necklace''. Thanks for the good, tragic, idea. By curiosity, why would the father kill himself? If other people have more ideas, be free to post. Thanks all.
*December 3, 2010*

**English lit**

Thank's for pointing that out Writeacher. I approve that Ms Sue's classic story is more in the spirit of Christmas, but I'm more in search of a story with a suprising ending. When you read the end, you're like : wow, who would have thought that...
*December 3, 2010*

**English lit**

So, for my english class, I'll have to write a Short story ( Exposition Rising Action Climax Falling action Resolution ) I'd like the story to be around the theme of christmas or horror during x-mas. So I need you guys to help inventing a story with a surprising ending...
*December 3, 2010*

**Math **

Reiny is right.
*December 3, 2010*

**earth**

? = 8 :D
*December 3, 2010*

**physics**

Also how did you just substitute mg in for the Normal Force. Cause when I solved for the normal force from the vertical components I got: FNcos A + mu*FNsin A = mg FN = mg / (cos A + mu*sin A) And I basically just substituted that into: FNsin A - mu*FNcos A = m*v^2/R I solved ...
*October 5, 2010*

**physics**

I know its been a while, but I'm just wondering how drwls solved the question without resolving friction into its x-component because isn't the centripetal acceleration directed horizontally instead of parallel to the incline and wouldn't the friction force be ...
*October 5, 2010*

**Statistics**

0.0213
*August 29, 2010*

**Biology**

thanks !
*June 3, 2010*

**Biology**

prokaryotes are not found in following kingdoms, except: (a) Monera (b) Protoctista (c) Animalia (d) All of these Help please!
*June 3, 2010*

**Biology**

prokaryotes are not found in following kingdoms, except: (a) Monera (b) Protoctista (c) Animalia (d) All of these Help please!
*June 3, 2010*

**Chemistry**

Opps... spelled Chemistry wrong.
*May 12, 2010*

**Chesitry**

Calculate the energy needed to melt 50.0 L of nitrogen (N2).
*May 12, 2010*