Friday

April 29, 2016
Total # Posts: 564

**math**

the half life of the carbon isotope C14 is about 5700 years. A. about how many years does it take 1000 grams of this substance to decay to 500 grams? B. about what percent of the original amount would you expect to find after 1000 years?
*October 9, 2013*

**physics**

A 74 kg box rests on a level surface. The coefficient of static friction, µS = 1.1 and the coefficient of kinetic friction, µK = 0.7 . What is the magnitude of Friction on the box from the surface?
*October 4, 2013*

**grammar**

In Which oneof the following sentences is the number written correctly? A.the parcel of land was advertised as two hundred forty-three and three-quarters acres.b.the college has an,endowment of more than $187million.c.john just paid $33 thousand forhis New car.d.one hundred ...
*August 8, 2013*

**Algebra**

A $130,000 home bought with a 20% down payment and the balance financed for 30 years at 7.5% Find the monthly payment for the loan
*June 5, 2013*

**CENCEPTS IN HEALTHCARE**

what is the procedures and resources available for assisting patients who use English as a second language, who is hearing impaired, sight impaired, or who have any other type of physical or diversity related disposition that should be addressed to provide quality care to that...
*June 2, 2013*

**chemistry**

i have never used the ice table before so i think its basic class. so do i just add those 2 numbers together? Thanks DrBob
*May 19, 2013*

**chemistry**

What is the hydrogen ion concentration, in mol dm−3, when 2.00 g of sulfuric acid is dissolved in water to give 0.400 dm3 of solution? could you explain in a simple and clear way please because im not very good at chemistry. thanks in advance
*May 19, 2013*

**PreCalculus**

Sin5x cos2x + cos5x sin2x=
*May 13, 2013*

**geometry**

were did you show me I dont have anything
*May 4, 2013*

**geometry**

How much more pizza is in a 12-in. diameter pizza than an 8-in. diameter pizza? Round your answer to the nearest hundredth. Be sure to show all work and label your answer. TWO points for the work...TWO points for the corrrect answer
*May 4, 2013*

**geometry**

4.2
*May 4, 2013*

**social studies**

making laws
*April 21, 2013*

**social studies**

The main work of representatives in a parliament is a.running trials b.trining an army c. kkeeping the peace d.making laws
*April 21, 2013*

**Physics (Algebra-based)**

A barefoot field-goal kicker imparts a speed of 35 m/s to a football initially at rest. If the football has a mass of 0.39 kg and the time of contact with the ball is 0.038 s, what is the force exerted by the ball on the kicker’s foot? I tried the formula F=(m(vf-vi))/...
*April 17, 2013*

**physics**

An elevator has a mass of 500 kg. It may safely carry an additional mass of 1000kg and accelerate upward at 2m/s2. What is the tension in the cable?
*April 14, 2013*

**Physics (Algebra-based)**

Thank you!
*April 6, 2013*

**Physics (Algebra-based)**

A block starts at rest and slides down a frictionless track except for a small rough area on a horizontal section of the track.It leaves the track horizontally, flies through the air, and subsequently strikes the ground. gravity= 9.81 m/s^2. height1=4.1m---- is initially ...
*April 6, 2013*

**help**

If you triple 4 and subtract 2 each day, how many days until you have zero?*
*April 4, 2013*

**math**

10 pounds
*March 14, 2013*

**Physics (Algerbra-based)**

Thank you!
*March 14, 2013*

**Physics (Algerbra-based)**

A particle is moving clockwise around a circle with a radius 3.31 m. The magnitude of the total acceleration of the particle at the given instant is 14.3 m/s^2; the angle between the vector of total acceleration and the radius-vector of the particle is 30◦. Find the ...
*March 14, 2013*

**Math**

David has 50 bills in his wallet worth $400 all fives and tens dollar bills. How many of each bill does he have
*March 8, 2013*

**algebra**

A line with a slope of -2 passes through the point (1, 7). What is the closest point on the line above (1, 7) which has whole number coordinates?
*March 4, 2013*

**Geography**

Would outdoor locations in countries such as Singapore with the highest temperatures also have the highest relative humidities? Explain 2 reasons? Would outdoor locations in countries such as Singapore with the highest temperatures necessarily have the highest dew point ...
*March 2, 2013*

**Math**

A bag contains two blue, three purple, four yellow, two red, three green and one orange marbles. What is the conditional probability that, without replacement, the second marble is purple given that the first marble was green?
*February 23, 2013*

**science**

describe how matter cycles through an ecosystem
*February 13, 2013*

**Calculus**

Find the derivative of m(x)=1/(x+1) by using the definition of the derivative.
*February 12, 2013*

**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*