Friday

February 5, 2016
Total # Posts: 885

**lube oil systems**

With many lube oil systems, it is common to cool the oil before it is pumped to the end user (engine, compressor, etc). However, for large centrifugal compressors, it is common to pump the lube oil hot, and cool the oil immediately before it enter the compressor. Since we know...
*January 29, 2014*

**compressor operations**

We are operating a centrifugal compressor. The gas composition does not change during this excursion. While holding suction pressure and flowrate constant, the inlet temperature rises. What would you expect to happen to the discharge pressure, and why
*January 29, 2014*

**Centrifulag pump curve**

Q4 The system on site is a pressure sand filter, with a service curve. The filter is backwashed using the feed pump, at a higher flow rate, shown as backwash curve. Service duty point : 3 m3/h Backwash duty point : 9 m3/h Part (a) (4 marks) What is the speed of the pump to ...
*January 29, 2014*

**compressors**

We have a compressor that has two problems ¡K the engine is constantly loaded to maximum, and the life of compressor valves is short. It is suggested to reduce the lift on the compressor valves. What problem would this help? Why would this help? What problem would this ...
*January 29, 2014*

**MATH**

A CERTAIN RECIPE ASKS FOR 2/9 CUP OF GRANOLA. HOW MUCH IS NEEDED TO MAKE 7/3 OF A RECIPE?
*January 21, 2014*

**MATH**

A CERTAIN RECIPE ASKS FOR 2/9 CUP OF GRANOLA. HOW MUCH IS NEEDED TO MAKE 7/3 OF A RECIPE?
*January 21, 2014*

**cosmology**

150 photons
*January 19, 2014*

**cosmology**

z=0.5
*January 19, 2014*

**cal**

In my book I have diff answer. Can you double check your work?
*December 26, 2013*

**cal**

The end plates (isosceles triangles) of the trough show below were designed to withstand a fluid force of 5800 lb. How many cubic feet can the tank hold without exceeding this limitation? Assuming the density is 62.4 lb/ft^3, the maximum volume is ____ ft^3. View the graph at...
*December 26, 2013*

**cal**

Solve the problem. Find the area between y=(x-2)e^(x) and the x-axis from x=2 to x=5.
*December 23, 2013*

**cal**

Find the area of the region enclosed by the curve y=xsinx and the x-axis for 7π ≤x ≤8π .
*December 23, 2013*

**cal**

Evaluate the integral. ∫5sec^(4)x dx I got 5(secx+tanx)^(5)+C. is it right.
*December 23, 2013*

**cal**

I have these ans. chocies: pi(e-1) 2pi(e^(2)-1) pi(e^(2)-1) pi e Is it pi(e^(2)-1)
*December 23, 2013*

**cal**

Solve the problem. Find the volume of the solid generated by revolving the region bounded by the curve y=lnx, the x-axis, and the vertical line x=e^(2) about the x-axis.
*December 23, 2013*

**calc**

Determine if the following functions grow faster, slower, or at the same rate as the function 2e^(2x) as x → ∞. a. 3.2^(2x) b. e^(x/6) c. 1/8 e^(2x)
*December 16, 2013*

**Astronomy**

Tut tut - this is meant to be all your own work!
*December 5, 2013*

**Statistics**

Your program plans to acquire a total of 600 end items costing $535 million over a five-year period. The first production contract is to be awarded in FY04. The number of items to be procured (not delivered) each year and their estimated cost (in then-year dollars) is shown ...
*December 3, 2013*

**cal**

i think i got the answer. thanks anyway..
*November 23, 2013*

**cal**

The function gives the distances (in feet) traveled in time t (in seconds) by a particle. Find the velocity and acceleration at the given time. s= √(t^2-5), t=3
*November 23, 2013*

**cal**

Find the largest open intervals where the function is concave upward. f(x)= x/x^2+1
*November 22, 2013*

**cal**

I was doing final review for my exam and the ans to this question is given 8x^(3/2)-1/4x^(3/2) at the end of the answer key sheet. i might have to check with my prof. But thank you Reiny & Jai.
*November 22, 2013*

**cal**

haha is it then 2x^(3/2)-1/x^(3/2)
*November 22, 2013*

**cal**

Find the largest open intervals where the function is concave upward. f(x)=x^4-8x^2
*November 21, 2013*

**cal**

Decide if the given value of x is a critical number for f, and if so, decide whether the point for x on f is a relative minimum, relative maximum, or neither. f(x)= 2x^3-3x^2-12x+18; x=2 the ans. is "Critical number, minimum at (2,-2) but dont know how?
*November 21, 2013*

**cal**

Find f"(x) for the function. f(x)= 2x^3/2-6x^1/2
*November 21, 2013*

**cal**

Use the differential to approximate the quantity to four decimal places. √(122)
*November 20, 2013*

**cal**

Where did you made error on the first one? did you typed wrong numbers or problem.
*November 20, 2013*

**cal**

Find dy for the given values of x and Δx. y=4/x^4+3√x; x=4, Δx=.5
*November 20, 2013*

**cal**

Perfect!!!
*November 20, 2013*

**cal**

Find the average value of the function on the given interval. f(x)= √x+2; [1,7]
*November 20, 2013*

**cal**

I'm lost here. I think i'm adding wrong numbers or something else here.
*November 20, 2013*

**cal**

Approximate the area under the curve and above the x-axis using n rectangles. Let the height of each rectangle be given by the value of the function at the right side of the rectangle. f(x)=3/x from x=2 to x=6; n=4
*November 20, 2013*

**cal**

Evaluate dy/dt for the function at the point. y√x+1 = 12; dx/dt = 8, x=15, y=3
*November 19, 2013*

**9th Grade Math**

How to write 0.023494751 and 0.040381247 as a percent rounded to one decimal? Would it be 2.3% and 4.0%?
*November 17, 2013*

**9th Grade Math**

How to change 84.9% and 88.1% to a decimal? Would it be 0.849 and 0.881?
*November 17, 2013*

**us history**

Leading the underground railroad in to further North to Canada, was due to the Fugitive Slave Act. is it true.
*November 16, 2013*

**Pipeline design**

Sketch a preliminary layout for the following heat exchanger systems. On the layout sketch indicate pipe work manifolds, access platforms, access for construction, operations and maintenance. In your answer we are looking for thought into the relative sizes of these heat ...
*November 14, 2013*

**cal**

A conical tank (with vertex down) is 12 feet across the top and 18 feet deep. If water is flowing into the tank at a rate of 18 cubic feet per minute, find the rate of change of the depth of the water when the water is 10 feet deep. I got 81/200pi ft/min.
*November 2, 2013*

**US History Mrs. Sue**

Select the group that best embraced the beliefs of Abraham Lincoln. Abolitionists or The Free Soil Party. Is it Abolitionists.
*October 31, 2013*

**math**

A box of chalk and 2 staplers cost $10. Three boxes of chalk and 2 staplers cost $18. Find the total cost of 1 box of chalk and 1 stapler.
*October 27, 2013*

**physics**

suppose the diver vaults off the springboard, leaving it with an initial speed of 3.50 m/s upward. use energy conservation to find his spped when he strikes the water.
*October 23, 2013*

**math**

I need help on study links 2.9 for 5 grade
*October 10, 2013*

**science**

light has what range of wavelength
*October 4, 2013*

**Calculus**

so answer would be none or nowhere.
*September 24, 2013*

**Calculus**

g(x)= {0 if x<0 {x^3-3x if 0≤x≤3 {3 if x>3 If it was like this one. Then what? Same
*September 24, 2013*

**Calculus**

g(x)= {0 if x<0 {x^2-2x if 0≤x≤2 {2 if x>2 Find all values x=a where the function is discontinuous. Is the answer 0 and 2 or just 2?
*September 24, 2013*

**Calculus**

So not continuous at x=-8 and function is not defined right.
*September 24, 2013*

**Calculus**

f(x)= |x−8| / x+8 Is the function is not continuous at x= -8,8 or just at -8.
*September 24, 2013*

**Calculus**

So the function is defined or not defined.
*September 24, 2013*

**Calculus**

f(x)= ⎨x^2-1 / x+1, for x not = -1 ⎨8, for x=-1 I'm trying to graph and determine the values of x for which the function is continuous. Does the graph looks like a u shape opening up or a line.
*September 24, 2013*

**Lubrication**

A pump fitted with 50mm bore ball bearings uses an oil whose viscosity ranges from 100cSt at cold pump start-up to 7.5Cst when running at maximum speed and load. If these viscosities are the safe limits for the oil, specify the maximum start-up speed and the maximum running ...
*September 23, 2013*

**Calculus**

Find the limit. lim x→1 x^4-5x^3+7x^2-6x+3 / x-1
*September 22, 2013*

**Calculus**

Also suppose If lim x→6 had been lim x→5 would that had been changed the answer. Or it would be same.
*September 22, 2013*

**Calculus**

My fault. Sorry about that. Thank you
*September 22, 2013*

**Calculus**

4^9 = 262144 Is this the answer!! I got 3.
*September 22, 2013*

**Calculus**

Give an appropriate answer. Let lim x→6 f(x)=81. Find lim x→6 4^√f(x).
*September 22, 2013*

**Mechanics**

In a direct acting pressure relief valve, 64 bar pressure is acting on the conical dart seating area and the dart is kept closed by a spring force of 50 kg opposing the pressure. (5) a) Determine the bore diameter on the seat. b) What will the spring force be if a pressure of ...
*August 21, 2013*

**Algebra**

center is (-4,3)
*July 28, 2013*

**Algebra**

Find center, vertices, foci. (x+4)^2/36 + (y-3)^2/100 =1
*July 28, 2013*

**Business Statistics**

a sample of 16 people reveals the mean consumption to be 60 gallons with the standard of deviation of 20 gallons
*July 28, 2013*

**trig**

Given that P=(-1,8) and Q=(-2,1), find the component form and magnitude of the vector 3 PQ.
*July 28, 2013*

**business math **

If you can earn 5%, how much will you have to save each year if you want to retire in 35 years with $1 million?
*July 23, 2013*

**trig**

tan(7π/4) + tan(5π/4) Does this = 0
*July 18, 2013*

**trig**

Simplify: csc^2 x sec x / sec^2 x + csc^2 x
*July 16, 2013*

**Algebra**

Determine whether the equation defines y as a function of x. y=-17
*July 15, 2013*

**trig**

tan (pi/2 - x) = sin (pi/2 - x) / cos (pi/2 - x) But sin (pi/2 - x) = cos x and cos (pi/2 - x) = sin x <=> tan (pi/2 - x) = cos x / sin x = cotan x <=> tan (pi/2 - x) * tan x = cotan x * tan x = (cos x / sin x) * (sin x / cos x) = 1
*July 14, 2013*

**trig**

simplify the expression. tan(π/2-x)tanx
*July 14, 2013*

**trig**

simplify the expression. cos^2x+sin^2x/cot^2x-csc^2x
*July 14, 2013*

**trig**

But my teacher gave the answer on the review as -1.
*July 14, 2013*

**trig**

simplify the expression. -sin^2x-cos^2x
*July 13, 2013*

**trig**

use basic identities to simplify the expression. csc θ cot θ / sec θ
*July 13, 2013*

**Algebra**

Determine whether the equation defines y as a function of x. y= -16
*July 12, 2013*

**statistics**

Investment analysts generally believe the interest rate on bonds is inversely related to the prime interest rate for loans; that is bonds perform well when lending rates are down and perform poorly when interest rates are up. Can the bond rate be predicted by the prime ...
*July 8, 2013*

**statistics**

Suppose a researcher gathered survey data from 19 employees and asked the employees to rate their job satisfaction on a scale from 0 to 100 (with 100 being perfectly satisfied). Suppose the following data represent the results of this survey. Assume that relationship with ...
*July 8, 2013*

**statistics**

Y=71745-678.964x =6495.786 So for 2012, y (8) = -972.77
*July 8, 2013*

**statistics**

Shown below are rental and leasing revenue figures for office machinery and equipment in the United States over a sever-year period according to the U.S. Census Bureau. Use these data to run a linear regression and then forecast the rental and leasing revenue for the year 2012...
*July 8, 2013*

**physics**

elena wtf are ypu smoking
*July 7, 2013*

**college algebra: probability and statistics**

50%
*June 30, 2013*

**pre cal**

x^2(4x^2+1)^7(76x^2+3)
*June 30, 2013*

**Maths**

what is the max value of y=x^22/10x^logx
*June 30, 2013*

**trig**

Write the complex number in trigonometric form, using degree measure for the argument. -12 - 16i
*June 28, 2013*

**trig**

Convert the rectangular coordinates to polar coordinates, using radian measure for the angle. (6, -6) 6√(2),7π/4 OR -6√(2),5π/4
*June 28, 2013*

**trig**

Solve the equation. Express your answer in trigonometric form. x^5 - 11 = 0
*June 28, 2013*

**trig**

Find the indicated roots. Write the answer in trigonometric form. Fourth roots of 256(cos 220° + i sin 220°)
*June 28, 2013*

**trig**

Use De Moivre's theorem to simplify the expression. Write the answer in a + bi form. [2(cos 240° + i sin 240°)]^5
*June 28, 2013*

**trig**

Find the dot product a*b. a= (5,-9), b=(4,-3)
*June 28, 2013*

**trig**

estimate the components of the vector. Round to one decimal place. [v] = 33.9, θ = 65.9° Find the horizontal and vertical components of v, and write in component form.
*June 28, 2013*

**trig**

find the indicated vector. let u = (-9,1), v=(-5,9). Find 3u+v
*June 28, 2013*

**trig**

Find z1z2 and z1/z2 for the pair of complex numbers using trigonometric form. z1=4+9i, z2=-5-5i I got z1z2 = 25-65i But cannot find the z1/z2.
*June 26, 2013*

**FND 154 Fundamentals of Accounting**

Show a journal entry for the Harwick Company that April 5, merchandise was purchased from Botharn Company for $23,000, terms 2/10, net/30,FOB shipping point
*June 24, 2013*

**trig**

slove the equation exactly over the interval [0, 2pi) sinx=1-2sin^2x
*June 21, 2013*

**trig**

use an identity to write the expression as a single trignometric function. squ root 1-cos48°/2
*June 21, 2013*

**trig**

choose the expression that is equivalent to the given expression. 2 cos^2 4x-1
*June 21, 2013*

**trig**

Use the fundamental identities to simplify the expression. cos^2θ/sin^2θ+cscθsinθ I got tan^2theta
*June 21, 2013*

**trig**

i got it now. thanks
*June 21, 2013*

**trig**

so the answer is 330
*June 21, 2013*

**trig**

fidn all values of tehta in [0, 360) that satisfy the equation. √(3)tan(θ/2)=-1 I have four choices 300, 330, 150 , 120 and i got 120
*June 21, 2013*

**trig**

Multiply and simplify. (cos x - sin x)^2
*June 21, 2013*

**trig**

Choose the expression that is equivalent to the given expression. sin 6x tan 3x I got 2 sin^2 3x
*June 21, 2013*