Friday

October 9, 2015
Total # Posts: 858

**Chemistry**

A sheet of aluminum (Al) foil has a total area of 2.119 ft2 and a mass of 2.714 g. What is the thickness of the foil in millimeters? (Density of Al = 2.699 g/cm3? I got 5.108*10^-4 cm but that is wrong. (2.714g)/(2.699g/cm^3)/(2.119ft^2) * 1ft/30.48cm = 5.108*10^-4 cm
*September 15, 2013*

**math**

Thanks for your help.
*September 11, 2013*

**math**

How would I show my work for this answers?
*September 11, 2013*

**math**

how do you write 3.08 as a fraction?
*September 11, 2013*

**econmics**

Suppose the price of widgets rises from $7 to $9 and consumption of widgets falls from 25 widgets a month to 15 widgets. Calculate your price elasticity of demand of widgets. What can you say about your price elasticity of demand of widgets? Is it Elastic, Inelastic, or ...
*September 10, 2013*

**Math**

How do you know if a steam and leaf display is uniform, unimodal or bimodal?
*September 5, 2013*

**Math**

One advantage of a _____________ is that the actual data values are retained in the graphical display of the data. A) Pie chart B) Dot plot (This one?) C) Histogram D) boxplot If we want to discuss any gaps and clusters in a data set, which of the following should not be ...
*September 5, 2013*

**Geometry**

The length of one side of an isosceles triangle is two times the base b. This length is equal to (8b - 12),in. What is the value of b?
*September 4, 2013*

**Math**

A two-player game is played with two piles of stones, with sizes m,n. On a player's turn, that player can remove any positive integer number of stones from one pile, or the same positive integer number of stones from each pile. A player loses when they are unable to take a...
*August 12, 2013*

**Math (Combinatorics) **

How many ways to rearrange 9 a's, 2 b's, and 2c's so that we never see bc and both b's always appear before both c's?
*July 30, 2013*

**calculus (please help steve)**

Evaluate ∬(x^2+y^2)^2/(x^2y^2) dx dy over the region common to the circles x^2+y^2=7x and x^2+y^2=11y.
*July 26, 2013*

**calculus (please help steve)**

ok, thanks!
*July 25, 2013*

**calculus (please help steve)**

But we are taking a double integral. This would be finding a volume.
*July 25, 2013*

**calculus (please help steve)**

Evaluate ∬(x^2+y^2)^2/(x^2y^2) dx dy over the region common to the circles x^2+y^2=7x and x^2+y^2=11y.
*July 25, 2013*

**calculus**

Evaluate ∬(x^2+y^2)^2/(x^2y^2) dx dy over the region common to the circles x^2+y^2=7x and x^2+y^2=11y.
*July 25, 2013*

**Calculus-HELP!!!**

wolfram alpha says (s^2+8)/(s^3+16s)
*July 25, 2013*

**calculus**

valuate ∬(x^2+y^2)^2/(x^2y^2) dx dy over the region common to the circles x^2+y62=7x and x^2+y^2=11y
*July 25, 2013*

**calculus**

Evaluate ∬R 1/sqrt(x^2+y^2) dx dy, where R is the region bounded by y≥0 and x^2−x+y^2≤0.
*July 25, 2013*

**calculus**

ok, thanks
*July 25, 2013*

**calculus**

could you give me a bit help on how to proceed if I were to use a volume integral?
*July 25, 2013*

**calculus**

Let V be the volume of the region bounded by x^2+y^2≥z^2, z≥0 and x^2+y^2+z^2≤1. What is the value of ⌊100V⌋?
*July 25, 2013*

**physics**

What is the wind speed in m/s required to keep a great white shark suspended in midair during a summer day on the California beach? Details and assumptions Model the shark as a horizontal cylinder 6 m long and 1 m in diameter. The air is at a pressure of 1 atm and a ...
*July 24, 2013*

**Data Structures and Algorithms**

545
*July 24, 2013*

**math**

Let S be the set of {(1,1), (1,−1), (−1,1), (1,0), (0,1)}-lattice paths which begin at (1,1), do not use the same vertex twice, and never touch either the x-axis or the y-axis. Let Sx,y be the set of paths in S which end at (x,y).For how many ordered pairs (x,y) ...
*July 23, 2013*

**math**

A token is placed on the leftmost square in a strip of four squares. You are allowed to move the token left or right along the strip by sliding it a single square, provided that the token stays on the strip. How many ways can the token be moved such that after 15 moves, it is ...
*July 23, 2013*

**physics**

integral (1+cos 2T) dT = T + sinTcosT so (2/Pi)v integral (1+cos 2T) dT from 0 to pi/2 = 1 ?
*July 23, 2013*

**physics**

so we would solve to get 66.51?
*July 23, 2013*

**physics**

so how would we apply this 3v/2 into your original equation rho * 2 r L v^2 = 1000(9.8)(pi r^2)(L) ?
*July 23, 2013*

**physics**

how did you get the volume of air that hits the shark per second?
*July 23, 2013*

**physics (fluids)**

If a object of radius 3 cm is attached to the ground in a 3 m deep sea, what is the vertical force in N with which the water (density = 1000 kg/m^3) presses on it?
*July 22, 2013*

**calculus (hint?)**

f(x) is a twice differentiable function such that f(2x)=f(x+5)+(x−5)^2 What is f''(x)?
*July 21, 2013*

**calculus**

If f(x)=∫ (from -x to x) cos(t)/(1+e^t) dt and x=asin(77/85), then the absolute value of f′(x)−f(x) can be expressed as a/b, where a and b are coprime positive integers. What is the value of a+b?
*July 20, 2013*

**calculus**

I would still like help as to how I would proceed. That is why I still ask for the answer.
*July 20, 2013*

**calculus**

However, I am still confused as to how I would proceed.
*July 20, 2013*

**calculus**

so what is the answer to the question?
*July 20, 2013*

**calculus**

If f(x)=∫ (from -x to x) cos(t)/(1+e^t) dt and x=asin(77/85), then the absolute value of f′(x)−f(x) can be expressed as a/b, where a and b are coprime positive integers. What is the value of a, and what is the value of b?
*July 20, 2013*

**calculus**

f(x) and f′(x) are continuous, differentiable functions that satisfy f(x)=x^3+4x^2+∫ (from 0 to x)(x−t)f′(t) dt. What is f′(5)−f(5)?
*July 20, 2013*

**calculus (point me in the right direction please?)**

but how would you get f(5)?
*July 19, 2013*

**calculus (point me in the right direction please?)**

f(x) and f′(x) are continuous, differentiable functions that satisfy f(x)=x^3+4x^2+∫(from 0 to x)(x−t)f′(t) dt. What is f′(5)−f(5)?
*July 19, 2013*

**calculus (point me in the right direction please?)**

thank you steve!
*July 18, 2013*

**calculus (point me in the right direction please?)**

Let V be the volume of the three-dimensional structure bounded by the region 0≤z≤1−x^2−y^2. If V=a/bπ, where a and b are positive coprime integers, what is a+b?
*July 18, 2013*

**physics**

114 mm Hg = 15198.75 pascals 16.0 cm^2 = 0.0016 m^2 P=F/A 15198.75=F/0.0016 F=24.318 newtons
*July 18, 2013*

**calculus**

he volume of the solid obtained by rotating the region bounded by x=(y−2)^2 and y=x about the x-axis has the form N/2π. What is the value of N?
*July 18, 2013*

**calculus**

oops! Thanks for the help
*July 18, 2013*

**calculus**

alright, so i got that f'(x)=4x^3-76x^2+4ax =4x(x^2-19x+4a) since this must never equal 0, it must have no solutions. Therefore, x must not be 0 and x^2-19x+4a must not be 0. For that to occur, 289-16a<0, so a > 18.0625. Can you please check me work? Sorry for ...
*July 18, 2013*

**calculus**

How many positive integers a (<1000) are there such that the function f(x)=x^4−76/3x^3+2ax^2 has no local maxima?
*July 18, 2013*

**calculus**

Are you just going to assume that any problem I ask for help on is from "Brilliant"?
*July 18, 2013*

**calculus**

How do you know anyways?
*July 18, 2013*

**calculus (could you help point me in the right direction?)**

could someone please point me in the right direction?
*July 18, 2013*

**calculus**

Let V be the volume of the three-dimensional structure bounded by the region 0≤z≤1−x^2−y^2. If V=a/bπ, where a and b are positive coprime integers, what is a+b?
*July 18, 2013*

**math**

If (x+2)f(2−x)+(2x+1)f(2+x)=1 for all real values of x, then f(18)=a/b, where a and b are coprime positive integers. What is the value of a+b?
*July 18, 2013*

**calculus**

How many integer values of a are there such that f(x)=x^+ax^2+8ax+25 has no local extrema?
*July 18, 2013*

**calculus**

A 3-dimensional structure is obtained from rotating the parabola y=x^2 about the y-axis. Each second, 2π units^3 of water is being poured into the structure from the top. When 8π units^3 of water has been poured in the structure, the instantaneous change in water ...
*July 18, 2013*

**calculus**

no, i think that ∫[0,2] π((4y)^2-(2y^2)^2) dy is 256/15π
*July 18, 2013*

**calculus**

i believe its bounded from y=0 to y=2
*July 18, 2013*

**calculus**

The area bounded by the curve 2y^2=x and the line 4y=x is rotated around the y-axis. The volume of the resulting structure can be expressed as V=a/bπ, where a and b are coprime positive integers. What is the value of a+b?
*July 18, 2013*

**calculus**

The area bounded by the curve 2y^2=x and the line 4y=x is rotated around the y-axis. The volume of the resulting structure can be expressed as V=a/bπ, where a and b are coprime positive integers. What is the value of a+b?
*July 17, 2013*

**calculus**

A 3-dimensional structure is obtained from rotating the parabola y=x^2 about the y-axis. Each second, 2π units^3 of water is being poured into the structure from the top. When 8π units^3 of water has been poured in the structure, the instantaneous change in water ...
*July 17, 2013*

**math calculus**

The volume of the solid obtained by rotating the region bounded by y=x^2−2x and y=x about the line y=9, has the form a/bπ, where a and b are positive coprime integers. What is the value of a+b?
*July 17, 2013*

**physics**

no its wrong!
*July 17, 2013*

**physics**

A clock is made out of a disk of radius R=10 cm which is hung by a point on its edge and oscillates. All of a sudden, a circular part right next to the hanging point of radius R/2 falls off, but the clock continues oscillating. What is the absolute value of the difference in s...
*July 17, 2013*

**physics**

Telephoto lenses allow one to "zoom in" on distant objects, making them bigger. A particular telephoto lens consists of a combination of two thin lenses having focal lengths of f1=20 cm and f2=−8 cm, respectively. The lenses are separated by a distance of d=15 ...
*July 17, 2013*

**math (please help steve)**

Brilli the ant randomly placed a token into a square on a 2×100 chessboard according to a probability distribution P. The token is then moved uniformly at random to one of the horizontally, vertically, or diagonally adjacent squares. The probability that the token is in ...
*July 17, 2013*

**math**

Brilli the ant is considering the complexities of a 5-dimensional universe. She wants to count the number of integer points that are distance sqrt(n) away from the origin. Let Tn be the set of ordered 5-tuples of integers (a1,a2,a3,a4,a5) such that a1^2+a2^2+a3^2+a4^2+a5^2=n....
*July 17, 2013*

**physics**

Telephoto lenses allow one to "zoom in" on distant objects, making them bigger. A particular telephoto lens consists of a combination of two thin lenses having focal lengths of f1=20 cm and f2=−8 cm, respectively. The lenses are separated by a distance of d=15 ...
*July 17, 2013*

**Maths**

f(x)is a function differentiable at x=1 and f'(1)=1/8. what is the value of f(x)-f(1) f'(x) denotes the derivative of f(x)
*May 24, 2013*

**Math**

I mean 4 cups not 2 cups
*May 23, 2013*

**Math**

No because he has 2 cups. It doesn't equal a gallon. 1 gallon = 16 cups.
*May 23, 2013*

**math**

So far they have $5000 in their fund. Timmy gave $450. Donna gave $900. How much did Kathy give? A. $4550 B. $4100 C. $3700 D. $365
*May 23, 2013*

**math**

Simplify.is what? 42 Ã· 6 + {1 Â· 7 - [7 + (6 - 1)]} A. 12 B. 2 C. 28 D. 14
*May 23, 2013*

**math**

Simplify. is What? 125 Â· 24 Ã· 6 + (8 - 1) A. 493 B. 509 C. 507 D. 500
*May 23, 2013*

**math**

Simplify. how can this be simplified? 42 Ã· 6 + {1 Â· 7 - [7 + (6 - 1)]}
*May 23, 2013*

**math**

Round 35,554,100 to the nearest ten thousand. is what Round 35,554,100 to the nearest ten thousand. A. 35,554,100 B. 35,550,000 C. 35,554,000 D. 36,000,000 ?
*May 23, 2013*

**augusta teh**

The sundae contained almost 40,741 pounds of ice cream and almost 10,580 pounds of syrup and topping. How many pounds did the sundae weigh?
*May 23, 2013*

**math**

39
*May 23, 2013*

**Algebra**

f(x) is a function differentiable at x=1 and fŒ(1)=1/8. What is the value of f(x)-f(1) f'(x) denotes the derivative of f(x)
*May 21, 2013*

**math**

If sin57=m Express the following 1. sin 237 2. Cos 33 3. Cos 3 4. Cos 66
*May 19, 2013*

**math**

Pls help
*May 19, 2013*

**Science (chemistry) help please**

The following data was obtained from titrating a solution containing 25 mL of 0.0100 M MgCl2 solution, 1 mL of NH3OH buffer, and 10 drops of Calmagite with EDTA. Calculate the concentration of EDTA. Report the answer with three sig figs. I don't know what to do? I know ...
*May 14, 2013*

**matter**

why is it important too descibe and compare matter
*April 29, 2013*

**matter**

why is it important too descibe and compare matter
*April 29, 2013*

**Probabilities**

Bibi wants to send invitations to some of her friends to come to her birthday party. She has contact information for 37 friends stored on her phone, but she only wants to invite 21 of those people to her party. She tries to send out a message to the 21 people, but her phone ...
*April 25, 2013*

**Midpoint Help / Math**

M(-4,-2) is the midpoint of RS. If S has coordinates (-2,5), find the coordinates of R.
*April 23, 2013*

**landmark project**

You can ask , What is the area of the Palace of Fine Arts ? Where is it located ? Who is the architect ?
*April 23, 2013*

**Algebra**

Suppose f(x) is some polynomial such that x−45 is a factor of f(x) . What value of x must be a root of f(x)=0 ?
*April 19, 2013*

**Geometry**

Circle G with center O is tangential to PA at A . Line PO extended intersects G at B (PO<PB ). C is a point on AB such that PC bisects angle APB .What is the measure (in degrees) of angle PCA ?
*April 16, 2013*

**Quantum Physics**

guess the right answer for 5a and don't forget to write CAPITAL K
*April 16, 2013*

**Quantum Physics**

Gyus, 5 is easier than you think! It takes exactly m steps from starting superposition (ay = 1/sqrt(K), ax = 1/sqrt(k)) to get to the solution (ay = 1, ax = 0), then it takes exactly m+1 steps to get back to initial state, but after each cycle the sign changes! So it looks ...
*April 16, 2013*

**Statistics**

The lifetime of computer chips is approximately normal with mean 1.4×106 hours and standard deviation 3×105 hours. The statistics department has 5 computers built with that chip as the main component. What is the probability that all 5 computers last longer than 1....
*April 12, 2013*

**Geometry**

Arpit is thinking of a 2-digit number where the tens digit is twice the ones digit. How many different numbers can Arpit be thinking of?
*April 11, 2013*

**Geometry**

ABC is a triangle with circumcenter O, obtuse angle BAC and AB less than AC. M and N are the midpoints of BC and AO respectively. Let D be the intersection of MN with AC. If 2AD=(AB+AC), what is the measure of angle BAC ?
*April 11, 2013*

**computer programming**

I need help with this problem please: Create the logic for a program that accepts input values for the projected cost of a vacation and the number of month until vacation. Pass both values to a method that displays the amount you must save per month to achieve your goal. Use ...
*March 31, 2013*

**MATH**

IF CATHY IS 24 YEARS OLD, HOW OLD WILL CATHY BE IN Y YEARS? Y - 24 Y + 24 24 - y 24 / Y
*March 27, 2013*

**German**

correct
*March 25, 2013*

**Earth Science**

If a sample contains 70g of Carbon 14 and 70g of Nitrogen 14, how many half lives has it undergone? (show all of your work)
*March 21, 2013*

**algebra 1 **

A salesperson at a clothing store earns a 5% commission on all sales. How much commission does the sale person earn on a 300$ sale?
*March 7, 2013*

**Physics**

Okay its like 98.8 or something...you have to convert miles per hour to meters per second. Then do (1/2)(Mass)(velocity) that'll give you your kinetic energy (work). Divide that by time to get Power. Remember, it gives you your answer in watts but Rawwaga's answers are...
*February 28, 2013*

**Engineering Economy**

What is the future worth of $1,000 in month 1, $1,040 in month 2, and amounts increasing by $40 per month through month 12, at the end of year 2 if the interest rate is 23.7631528% per year, compounded continuously?
*February 26, 2013*

**Physics **

A mass is attached to a spring stretches it 2.5 cm from equilibrium. The mass is lightly tapped and set in an oscillation. What is the angular frequency of the of the oscillation?
*February 19, 2013*

**Math**

What is the minimum value of N that will make this statement true: If we pick any N composite numbers from 1 to 1000, then we can find 2 numbers whose greatest common divisor is not 1.
*February 15, 2013*