Friday

July 3, 2015

July 3, 2015

Total # Posts: 535

**Calculus**

k=+/- 8 I figured it out.
*February 4, 2013*

**Calculus**

It is supposed to be x^2-k^2 over x-8 And the limit is 8
*February 4, 2013*

**Calculus**

Find a value of the constant k such that the limit exists. x^2-k^2 lim _________ x->8 x-8 k=+/_
*February 4, 2013*

**Pre-Calculus**

An Alfa Romeo going at 70 mph requires 169 feet to stop. Assuming that the stopping distance is proportional to the square of velocity, find the stopping distances required by an Alfa Romeo going at 35 mph and at 140 mph (its top speed).
*February 3, 2013*

**Pre-Calculus**

A pomegranate is thrown from a ground level straight up into the air at time t = 0 with velocity 67 feet per second. Its height at time t seconds is f(t)=-16^2+67t. (a) Find the time it hits the ground and (b) the time it reaches its highest point. (c) What is the maximum ...
*January 31, 2013*

**Pre-Calculus**

For a boat to float in a tidal bay, the water must be at least 2.5 meters deep. The depth of the water around the boat, d(t), in meters, where t is measured in hours since midnight, is d(t)=5+4.6sin(0.5t) Use three decimal places in all intermediate calculations. (a) What is ...
*January 28, 2013*

**Pre-Calculus**

Find a solution to the equation if possible. Give the answer in exact form and in decimal form rounded to three decimal places. 1=21tan(2x+2)-6
*January 28, 2013*

**3rd grade math**

30/100 = 3/10
*January 28, 2013*

**Pre-Calculus**

The exponential function y(x)=Ce^ax satisfies the conditions y(0)=6 and y(1)=7. (a) Find the constants C and a. Enter the exact value of a. (b) Find y(2). Enter the exact answer. Simplify the answer so it does not contain any logarithms.
*January 28, 2013*

**Pre-Calculus**

At time t hours after taking the cough suppressant hydrocodone bitartrate, the amount A, in mg, remaining in the body is given by A=13(0.82)^t. a) What was the initial amount taken? b) What percent of the drug leaves the body each hour? c) How much of the drug is left in the ...
*January 28, 2013*

**math**

Chord BC is drawn in a circle with a radius of 3cm. Chord BS is 4cm long. Find the perpendicular distance from A to chord BC
*January 20, 2013*

**Early Child Educ.**

the newest organization to accredit afterschool programs is the
*December 27, 2012*

**BIOCHEMISTRY. PLEASE HELP! URGENT!!!!!**

Appreciate if you could help me answering the following questions! thank you!! How would you prepare a 20% homogenate from a 2.0g of liver using 0.25M sucrose? why is it necessary to cool the homogenate during homogenization?
*December 2, 2012*

**Biochemistry**

Appreciate if you could help me answering the following questions! thank you!! How would you prepare a 20% homogenate from a 2.0g of liver using 0.25M sucrose? why is it necessary to cool the homogenate during homogenization?
*December 1, 2012*

**Chemestry**

Find the molarity of a solution containing 0.75 mol of NaCl with a volume of 1.5 L.
*November 23, 2012*

**Math**

Ella walked 4.5 km/h to her friends house. She walked back home from her friends house at 3.5 km/h. She walked a total of 40 minutes. How many minutes was her walk on her way to her friends house?
*November 19, 2012*

**algebra**

my scenario, to start a small business you will need a loan of $50.000 to purchase the restaurant. The bank interest rate 9% that compounds monthly for 7 years. What is the monthly payment for this loan, what is the fomula that you will use and the values for each variable to ...
*November 12, 2012*

**algebra**

a small business loan in the amount of 50,000 need to interest rate of 9% that compounds monthly for 7 years. What is the payment for 7 years, need formula for this. And what is the balance of the loan at the end of the 1st year? Show the formula used for each variable and the...
*November 12, 2012*

**CALC #**

Use Green's Theorem to evaluate F · dr. C (Check the orientation of the curve before applying the theorem.) F(x, y) = y cos x − xy sin x, xy + x cos x , C is the triangle from (0, 0) to (0, 12) to (3, 0) to (0, 0)
*November 9, 2012*

**math**

how do you figure out the diameter of a pipe that is 40 feet high and holds 200000 gallons
*October 23, 2012*

**Chemistry**

thank you!!
*October 21, 2012*

**Chemistry**

someone help pls!! percentage of ethanol in the "blood" sample on a v/v basis is 0.0143% v/v. is the "blood" sample analysed over the limit for driving? (legal limit is 80mg alcohol per 100mL blood. assume the density of ethanol is 0.785g/mL and the density...
*October 21, 2012*

**Algebra**

4ã(50x)+3ã(2x)+ã(72x) Combine. Assume that all variables represent nonnegative real numbers.
*October 15, 2012*

**Calc 3**

The DNA molecule has the shape of a double helix. The radius of each helix is about 10 angstroms (1 Å = 10−8 cm). Each helix rises about 34 Å during each complete turn, and there are about 2.9 × 108 complete turns. Estimate the length of each helix. (...
*October 10, 2012*

**Calc 3 PLEASE HELP!!!!**

no you have to use lagrange multipliers to do it and i figured out all five equations but i can not solve any of them
*October 4, 2012*

**Calc 3 PLEASE HELP!!!!**

Find the maximum and minimum volumes of a rectangular box whose surface area is 1300 cm2 and whose total edge length is 200 cm.
*October 4, 2012*

**Calc 3**

If a function of one variable is continuous on an interval and has only one critical number, then a local maximum has to be an absolute maximum. But this is not true for functions of two variables. Show that the function f(x,y)= 3xe^y − x^3 − e^(3y )has exactly one...
*October 1, 2012*

**Math**

The base of an isosceles triangle is one inch shorter than the equal sides, and the altitude of the triangle is two inches shorter than the equal sides. What is the length of the equal sides?
*September 30, 2012*

**chemistry**

Identify a haloalkane and describe the manner in which it functions as an anesthetic.
*September 29, 2012*

**Calc 3**

Find parametric equations for the tangent line to the curve of intersection of the paraboloid z = x^2 + y^2 and the ellipsoid 6x^2 + 5y^2 + 7z^2 = 39 at the point (−1, 1, 2)
*September 28, 2012*

**Calc 3**

can you please explain to me where you got the numbers for T(-1,1,2) I know you did the cross product but I can not seem to get the same numbers as you. Please explain
*September 27, 2012*

**Calc 3**

Find parametric equations for the tangent line to the curve of intersection of the paraboloid z = x2 + y2 and the ellipsoid 6x2 + 5y2 + 7z2 = 39 at the point (−1, 1, 2)
*September 27, 2012*

**Calc 3**

At what point on the paraboloid y = x2 + z2 is the tangent plane parallel to the plane 7x + 2y + 3z = 2? (If an answer does not exist, enter DNE.)
*September 27, 2012*

**Lang Arts**

Would #2 be A?
*September 25, 2012*

**physics**

Two blocks are connected by a lightweight, flexible cord that passes over a frictionless pulley. If m1 = 3.8 kg and m2 = 9.2 kg, and block 2 is initially at rest 140 cm above the floor, how long does it take block 2 to reach the floor?
*September 23, 2012*

**physics**

Two blocks are connected by a lightweight, flexible cord that passes over a frictionless pulley. If m1 = 3.8 kg and m2 = 9.2 kg, and block 2 is initially at rest 140 cm above the floor, how long does it take block 2 to reach the floor?
*September 23, 2012*

**Calc 3**

thank you!!!!!!
*September 22, 2012*

**Calc 3**

Use the Chain Rule to find ∂z/∂s and ∂z/∂t. z = tan(u/v), u = 7s + 4t, v = 4s − 7t
*September 22, 2012*

**Calc 3**

we were not given f(x,y) the whole problem is listed above, apparently there is a link that is supposed to help us but I followed it and don't know what I am doing wrong and I cannot post the link because it is on a special homework website.
*September 22, 2012*

**Calc 3**

If z = f(x, y), where x = r^2 + s^2 and y = 8rs, find ∂^2z/(∂r ∂s).
*September 22, 2012*

**calc 3**

yes i already got parts a and b i do not know how to do part c sorry i should have specified that in my post
*September 21, 2012*

**calc 3**

The length script l, width w, and height h of a box change with time. At a certain instant the dimensions are script l = 7 m and w = h = 5 m, and script l and w are increasing at a rate of 6 m/s while h is decreasing at a rate of 4 m/s. At that instant find the rates at which ...
*September 21, 2012*

**English**

1.I started play the oboe because [I've heard] it was a challenging instrument (a) no change (b) I'd have heard (c)I've been hearing (d) I'd heard 2. That was [four years ago and, I've] enjoyed learning to play (f) no change (g) four years ago, and I've...
*September 20, 2012*

**physics**

A crate of potatoes of mass 13.0 kg is on a ramp with angle of incline 30° to the horizontal. The coefficients of friction are μs = 0.76 and μk = 0.35. Find the frictional force (magnitude and direction) on the crate if the crate is sliding up the ramp.
*September 20, 2012*

**calc 3**

Use the Chain Rule to find dw/dt. w = ln (x^2 + y^2 + z^2)^.5 , x = 9 sin t, y = 6 cos t, z = 7 tan t
*September 20, 2012*

**Calc 3**

Find all partial derivatives? v = (xy)/(x-y) vxx= vxy= vyx= vyy=
*September 20, 2012*

**physics**

A barge is hauled along a straight-line section of canal by two horses harnessed to tow ropes and walking along the tow paths on either side of the canal. Each horse pulls with a force of 540 N at an angle of 12° with the centerline of the canal. What is the net force on ...
*September 19, 2012*

**calc 3**

Find all partial derivatives? v = (xy)/(x-y) vxx= vxy= vyx= vyy=
*September 19, 2012*

**calc 3**

Use polar coordinates to find the limit. [If (r, θ) are polar coordinates of the point (x, y) with r ≥ 0, note that r → 0+ as (x, y) → (0, 0).] (If an answer does not exist, enter DNE.) lim (x, y)→(0, 0) [(3e^−x^2− y^2) − 3]/ (x^2...
*September 17, 2012*

**Calc 3**

but there is no lHospitals rule in multivariable
*September 14, 2012*

**Calc 3**

Find the limit, if it exists. (If an answer does not exist, enter DNE.) lim (x, y)→(0, 0) of (x^2 + y^2)/[((x^2 + y^2 +64)^.5)-8]
*September 14, 2012*

**Calc 3**

A cooling tower for a nuclear reactor is to be constructed in the shape of a hyperboloid of one sheet. The diameter at the base is 300 m and the minimum diameter, 500 m above the base, is 200 m. Find an equation describing the shape of the tower in the coordinates where the ...
*September 12, 2012*

**Chemistry**

1.42 g/cm^2 to mg/mm^2
*September 4, 2012*

**calc 3**

The magnitude of a velocity vector is called speed. Suppose that a wind is blowing from the direction N45°W at a speed of 40 km/h. (This means that the direction from which the wind blows is 45° west of the northerly direction.) A pilot is steering a plane in the ...
*August 31, 2012*

**calc 3**

Question Find an equation of the set of all points equidistant from the points A(−2, 5, 2) and B(5, 1, −3).
*August 30, 2012*

**calculus**

hi i think i know what you mean already. my answer for F"(v) (-150v^5/2 + 40500v)/v^4 i simplified further, it became (-150v(v^3/2 - 270))/v^4 cancel off the common factor v it became (-150(v^3/2 - 270))/v^3 Am i correct??
*August 13, 2012*

**calculus**

based on my question, i retyped... F(v) : (600v^3/2 + 20250)/v F'(v) : (300v^3/2 - 20250)/v^2 F"(v) : (-150v^5/2 + 40500)/v^3 Reiny, isn't your answer suppose to be f(x) = 600 v^(3/2) + 20250 v^-1, instead of f(x) = 600 v^(1/2) + 20250 v^-1 ?? 1/2 power and 3/2 ...
*August 13, 2012*

**calculus**

I do not want the simplified answer by the way...I need the answer as an expression only
*August 13, 2012*

**calculus**

Ok but the power 5/2 is wrong? Should have been power 3/2? I keep on getting the answer 5/2.. I don't know which part of my working is wrong
*August 13, 2012*

**calculus**

Just want to check whether my answer is correct for quotient rule F(v) : (600^3/2 + 20250)/v F'(v) : (300^3/2 - 20250)/v^2 F"(v) : (-150v^5/2 + 40500)/v^3 Can anyone let me know whether my answer is correct for first and second derivative based on F(v) ??
*August 13, 2012*

**calculus**

yes it should be, F(v) : (600^3/2 + 20250)/v F'(v) : (300^3/2 - 20250)/v^2 F"(v) : (-150v^5/2 + 40500)/v^3 for F"(v), this is how i get: F'(v) : (300^3/2 - 20250)/v^2 F"(v) : ((300v^3/2 - 20250)' * v^2) - ((300v^3/2 - 20250) * (v^2)')/v^4 F"...
*August 13, 2012*

**calculus**

nope, it's not a typo. the 5/2 is the power of 5 over 2. it is not 5 divide by 2. is my above answer correct?
*August 13, 2012*

**calculus**

Just want to check whether my answer is correct for quotient rule F(x) : (600^3/2 + 20250)/v F'(x) : (300^3/2 - 20250)/v^2 F"(x) : (-150v^5/2 + 40500)/v^3 Can anyone let me know whether my answer is correct for first and second derivative based on F(x) ?? Thank you!!
*August 13, 2012*

**calculus**

A ship uses $( 7v^2 ) of fuel per hour when travelling at a constant speed of v km/h. Other expenses in operating the ship (i.e. crew and equipment) amount to $345 per hour. The ship makes a journey of 100 km. C(v) : (700v^2 + 34500)/v C'(v): (700v^2 - 34500)/v^2 C"(v...
*August 13, 2012*

**calculus**

i got the answer!! thank you!!!
*August 13, 2012*

**calculus**

pls ignore the above question... to make it clearer for the question, it is... f(x): (700v^2 + 34500)/v f'(x) : (700v^2 -34500)/v^2 f''(x) : ???
*August 13, 2012*

**calculus**

The question should be: f(x): 700v^2 + 34500/v f'(x) : 700v^2 -34500/v^2 f''(x) : ???
*August 13, 2012*

**calculus**

sorry typo error above, question is, f(x): 700v^2 + 34500/v f'(x) : 700v^2 -34500/v^2 f"'(x) : ???
*August 13, 2012*

**calculus**

how to find the second derivative of quotient rule? f(x): 700v^2 + 3450/v f'(x) : 700v^2 -3450/v^2 f"'(x) : ???
*August 13, 2012*

**calculus**

The 5 question is asking how many km/h...appreciated if anyone cld help...thank you!!
*August 12, 2012*

**calculus**

Hi i need help in this. Some of the parts i got the answer but some i don't. please help! A ship uses $(7v^2) of fuel per hour when travelling at a constant speed of v km/h. Other expenses in operating the ship (i.e. crew and equipment) amount to $345 per hour. The ship ...
*August 12, 2012*

**calculus**

i get the answer already! thank you!
*August 11, 2012*

**calculus**

Hi thanks for helping. But when differentiate pi^2 isn't that is 2pi? How come your answer is 2pi^2? and when different r^2 isn't that is 2r? How come your equation is dv/dt = 2pi^2 D r + 8/3*pi*r^2? Because my answer is 2pi D 2r + 8/3*pi*r*^2. anyone can explain? Thanks!
*August 11, 2012*

**calculus**

A bicycle wheel has a diameter D = 60 cm and the tyre has a cross sectional radius of r = 2.5 cm. The volume V of the inner tube is given by V = pi^2 D r^2 + (8/3*pi*r^3) If air is being pumped into the tyre so that the volume of the inner tube is increasing at the rate of 12 ...
*August 11, 2012*

**math**

In a time-use study, 20 randomly selected managers were found to spend a mean of 2.40 hours each day on paperwork. The standard deviation of the 20 scores is 1.30 hours. Also, the sample data appear to have a bell-shaped distribution. Construct the 95% confidence interval for ...
*July 29, 2012*

**statistics**

One of the problems with a study such as this one is the small size of the samples. If you wanted to estimate the proportion of a certain color of candy to within 2% of the actual proportion, how many individual pieces of candy must you sample? Assume you want to be 90% ...
*July 23, 2012*

**LIT 210**

What do you think Oedipus Rex and A Raisin in the Sun imply about Sophocles’ and Lorraine Hansberry’s cultural identities?
*July 20, 2012*

**Math**

thank you!!
*June 30, 2012*

**Math**

Im working on a math question and the answer is 2hr and 24min. I am getting 2.4 with my calculations how do i take 2.4 and get 2hr and 24min.???
*June 30, 2012*

**Algebra**

Thank you been 8 years and trying to go back to school trying to re learn and or remember thanks a bunch!!!!
*June 28, 2012*

**Algebra**

If two planes leave the same airport at 1:00 PM, how many miles apart will they be at 3:00 PM if one travels directly north at 150 mph and the other travels directly west at 200 mph? I understand that d = sqrt[300^2 + 400^2] d = sqrt[250,000] But im not sure how you get 500 ...
*June 28, 2012*

**Finance**

Carnation needs to buy a $12,500 part the part company is offering cash discount terms of 4/10, n30. Carnation has a tight cash flow, wants to discount a 180 day note dated February 12 with a maturity value of $10,300. Bank offers a discount rate of 6%. Should carnation ...
*June 6, 2012*

**Physics**

Two spherical objects with a mass of 7.60 kg each are placed at a distance of 2.93 m apart. How many electrons need to leave each object so that the net force between them becomes zero?
*June 6, 2012*

**physics**

Two small pith balls, each of mass m = 16.6 g, are suspended from the ceiling of the physics lab by 1.8 m long fine strings and are not moving. If the angle which each string makes with the vertical is è = 19°, and the charges on the two balls are equal, what is the...
*June 6, 2012*

**math**

pam is offered a salary of 28,000 a year for 30 years with annual raises of 6 % what would be pam's salary during her 5th year on the job
*April 26, 2012*

**Math**

The weights of adult long-tongued fruit bats are known to be normally distributed with a mean of 20.22 grams and a standard deviation of 3.23 grams. What is the probability that a randomly selected bat will: a) weigh at most 15 grams? b) weigh less than 30 grams?
*March 23, 2012*

**math**

The weights of adult long-tongued fruit bats are known to be normally distributed with a mean of 20.22 grams and a standard deviation of 3.23 grams. What is the probability that a randomly selected bat will: a) weigh at most 15 grams? b) weigh less than 30 grams?
*March 21, 2012*

**Physics**

wow I thought this was a homework help site. Not a be rude to someone you don't even know site? I have read the book thanks but physics is a hard topic to understand. You wasted your own time by commenting that rude comment. Thanks bye x
*March 21, 2012*

**Physics**

Tim and Ray have the same mass and they both climb up the same hill. Tim climbs the hill in 12 minutes and Ray in 22 minutes. a) Who does more work? b) Who develops the most power?
*March 21, 2012*

**Physics**

A blue whale materializes 11.5 km above an airless planet with an acceleration of gravity of 6.85 m/s2. What is the speed of the whale right before impact? (Work-Energy Theorem)
*March 21, 2012*

**Physics**

A car is driven at a constant speed of 85 km/h down a road. The car's engine delivers 49.2 kW of power. Calculate the average force that is resisting the motion of the car.
*March 21, 2012*

**Physics**

Michelle pulls a 14.5 kg wheeled cart with a rope along a flat road. The rope makes a 28.0 degree angle with the horizontal. If the tension in the rope is 350 N and she pulls the cart 56.7m how much work does Michelle do?
*March 21, 2012*

**Physics**

Bryant is fired from a cannon with an initial speed of 14 m/s. If his mass is 80 kg what is his initial kinetic energy?
*March 21, 2012*

**Physics**

A ball is moving at 82 m/s when it hits a ball at rest which has a mass fours times as big as its own. The formally stationary ball leaves the collision with a speed of 7.5 m/s what is the final velocity of the first ball?
*March 21, 2012*

**physics**

Neona is on a tricycle A, combined mass 62 kg, and Alyssia is on tricycle B, combined mass 54 kg. They are initially at rest, but they push off of each other. What is Neona's speed immediately after the push if Alyssia's is 4.2 m/s?
*March 21, 2012*

**Physics**

Kenya finally loses her cool and punches her teacher. The teacher weighs 85 kg. He sees the punch coming and begins to back up at a speed of 0.60 m/s. After Kenya clocks him, he is moving backwards at a speed of 0.82 m/s. If the contact time of Kenya's fist to the teachers...
*March 21, 2012*

**Physics**

Two trucks that appear to be identical collide on an icy road. One was originally at rest. The trucks stick together and move off at more than half the original speed of the moving truck. What can you conclude about the contents of the two trucks?
*March 21, 2012*

**Physics**

You are sitting at a baseball game when a foul ball comes in your direction. You prepare to catch it barehanded. In order to catch it safely, should you move your hands toward the ball, hold them still, or move them in the same direction as the moving ball? Explain.
*March 21, 2012*

**Physics**

As you lift a chair to store is upside down on a desk, gravity exerts a force, mg, downward and you exert a force of the same magnitude upwards. The two forces are equal in magnitude and opposite in direction. From this is would appear that no work was done, but you know you ...
*March 21, 2012*

**Physics**

Roads seldom go straight up a mountain, they wind back and forth. Explain why this is useful
*March 21, 2012*