W
Most popular questions and responses by W
chemistry
The chemical analysis of aspirin indicates that the molecule is 60.00% carbon, 4.44% hydrogen, and 35.56% oxygen. What is the emperical formula for asprin?
asked on January 20, 2010 
Chemistry
2 B5H9(l)+12 O2(g)>5 B2O3(s)+9 H2O(l) Calculate the kilojoules of heat released per gram (kJ/g) of the compound reacted with oxygen. The standard enthalpy of formations of B5H9(l), B2O3(s), and H2O(l) are 42.84, 1271.94, and 285.83 kJ/mol,
asked on November 1, 2010 
Physics
Sam, whose mass is 71.0 kg , takes off down a 51.0 m high, 11.0 ∘ slope on his jetpowered skis. The skis have a thrust of 210 N . Sam's speed at the bottom is 41.0 m/s .
asked on October 1, 2015 
Statistics
In a sample of 20 men, the mean height was 178 cm. In a sample of 30 women, the mean height was 164 cm. What was the mean height for both groups put together? The answer I got by adding the two means and dividing them by 2 is 171 but it is wrong, it must
asked on September 20, 2016 
Math/Finance
General Hospital has a current ratio of 0.5. Which of the following actions would improve (increase) this ratio? (Hint: Create a simple balance sheet that has a current ratio of 0.5. Then, judge how the transactions below would affect the balance sheet.)
asked on February 21, 2012 
calculus
The halflife of Radium223 is 11.43 days. If a sample has a mass of 400 mg, find the mass (in mg) that remains after 6 days
asked on October 14, 2014 
algebra
The length of a spring is a linear function of the mass of the object hanging from it. For a particular spring, the length was 12 centimeters when a 2kg mass was attached to it. When a 5kg mass was hung from it, it stretched to a length of 18 cm. Which
asked on June 16, 2013 
ADHD
Which of the following is true of the cause and treatment of ADHD ? A. Drug therapy alone is not very effective in treating hyperactivity b. academic and social skills are best treated with a combination of medication and other treatment. C. Usually caused
asked on October 2, 2015 
chemistry
A compound was found to contain 49.98 g carbon and 10.47 g hydrogen. The molar mass of the compound is 58.12 g/mol. What is the molecular formula?
asked on January 20, 2010 
phisecs
water is moving with a speed of 5 m/s through a pip with a crosssectional area of 4cm^2 . the water gradual descends 10 m as the pipe crosssectional area increases 8cm^2 . if the pressure at the upper level is 1.5*10^5 , the pressure at the lower level
asked on April 22, 2014 
Physics
Blood from an animal is placed in a bottle 1.3 m above a 3.6 cm long needle, of inside diameter 0.35 mm , from which it flows at a rate of 2.1 cm3/min . What is the viscosity of this blood? Assume ρblood=1.05×103kg/m3.
asked on March 7, 2017 
science
Describe the change in phase and temperature as water moves from the oceans to the atmosphere and then returns to Earth again as rain. A) evaporation: temperature increases; condensation: temperature decreases; precipitation (rain): temperature decreases.
asked on February 11, 2019 
chemistry
The pain reliever morphine contains 17.900 g C, 1.680 g H, 4.225 g O, and 1.228 g N. What is the emperical formula of morphine?
asked on January 20, 2010 
math
Austin is building a building a rabbit pen with 25 feet of fence. What are the dimensions of the rectangle he should build to have the greatest possible area?
asked on April 11, 2019 
Statistics
I have been working on the following homework problem: Consider Homer and Bart's consumption of potato chips and donuts. Suppose that Marge is in the room 30% of the time that Bart is eating chips and 40% of the time that Bart is eating donuts. Similarly,
asked on April 23, 2015 
Calculus
A block of ice is exposed to heat in such a way that the block maintains a similar shape as it metls. The block of ice is initially 2' wide, 2 'high, and 3' long. If the change in the width of the ice is 1/3 ft/hr, find: the amount of time it will tak
asked on February 7, 2012 
science weather
The hurricane center is MOST likely to be near location ___________ on Monday afternoon. A) I B) II C) III D) IV
asked on February 11, 2019 
Calculus
I am having trouble differentiating x^2 + 2lny = y (solving for dy/dx). I know that I need to do implicit differentiation, but the answer I get is not correct. The answer I got was (2x2xy)/2, but the answer is (2xy)/(y2). How do I do this problem?
asked on November 30, 2011 
physics
19. In Figure 101, if the force exerted on a 3.0kg backpack that is initally at rest is 20.0 N and the distance it acts over is 0.25 m, what is the final speed of the backpack?
asked on November 15, 2011 
chemistry
A sample of silver chromate (Ag2CrO4) has a mass of 29.0 g. How many CrO42 ions are present?
asked on January 20, 2010 
M
Small muscle usually occurs before large muscle development think false
asked on November 20, 2014 
Calculus
Find a power series, centered @ x=0, for function f(x)=x/(1+2x). I know this is a maclaurin series, but my work doesn't get the right answer. Can you please show steps? Also,do all power series start with a 1, as in (1+2x+4x^2+...)? Thanks in advance!
asked on March 8, 2012 
chemistry
A compound was found to contain 49.98 g carbon and 10.47 g hydrogen. The molar mass of the compound is 58.12 g/mol. What is the molecular formula?
asked on January 20, 2010 
geometry
a 16 by 18 foot rectangular section will be covered by square tiles that measured 2 feet on each side if the tiles are not cut how many of them will be needed to cover the section of the wall
asked on October 4, 2013 
Calculus
Find a power series, centered @ x=0, for function f(x)=x/(1+2x). I know this is a maclaurin series, but my work doesn't get the right answer. Can you please show steps? Also,do all power series start with a 1, as in (1+2x+4x^2+...)? Thanks in advance!
asked on March 8, 2012 
calculus
How do I integrate x(arctanx) dx? Is it some sort of integration by parts? Can you please show steps? Thanks in advance!
asked on December 15, 2011 
Calculus
If 3x^22y^2=4xy + 20, find the point(s) at which the graph from Problem 28 has vertical tangents. I found that dy/dx= (3x2y)/(2x+2y), but now I don't know what to do. Do I set dy/dx to 0?
asked on December 14, 2011 
phisecs
In a period of 3 h, a man walks 13 km north, turns around and walks 5 km south. Find his average velocity in km/h? Please pay attention to sign. () means the average velocity is to the south, (+) means the average velocity is to the North.
asked on February 20, 2014 
Calculus
How do I find the limit of (1+sin(pi times x))^(1/x) as x approaches 0? I tried using wolframalpha, but am unable to understand their steps. My thinking is that you set y=the limit and use L'hopital's rule a couple times. The answer I got was y=e^0>y=1,
asked on January 19, 2012 
Calculus
The point (1,2) is on the graph of y^2x^2+2x=5. Find the value of (dy/dx) and (d^2y/dx^2) at the point (1,2). How do I find (d^2y/dx^2)? I found. I found (dy/dx) to be 2y(dy/dx)2x+2=0, but I don't know how to take the derivative of that to
asked on October 18, 2011 
math
two baseball players bat first and second in the lineup the first batter has on base percentage of 0.46 the second batter has an on base percentage of 0.31 if someone is on base but only 0.23 if the bases are empty at the start of the game what is the
asked on January 5, 2011 
chemistry
How many moles are there in 4.76e24 atoms Al?
asked on January 20, 2010 
chemistry
A sample of carbon dioxide has a mass of 47.4 g. How many carbon atoms are present?
asked on January 20, 2010 
physics
Sam and Sue are running side by side in a marathon. They are running at a constant velocity of 10 km h . What is Sue's relative velocity to Sam? A) 0 km/h B) 5 km/h C) 10 km/h D) 20 km/h
asked on October 26, 2016 
Child development
Refers to breaking down complex skills into their component parts? A. Differentiation b. integration c. Motor skills d. Locomotion I am think b but am not sure if it right.
asked on October 2, 2015 
phisecs
`filling the blanks: sun_________________ than moon. earth is__________________mercury.''.
asked on February 21, 2014 
phisecs
In a period of 3 h, a man walks 13 km north, turns around and walks 5 km south. Find his average velocity in km/h? Please pay attention to sign. () means the average velocity is to the south, (+) means the average velocity is to the North.
asked on February 21, 2014 
englsih
what is writing conventions and how do i improve min
asked on September 29, 2013 
math
How do I find the length of curve f(x)=3x^22x+3 on the interval [1,4]? I have no idea on how to start this. Anyways, thanks in advance!
asked on November 15, 2011 
School
Daily activity can boost academic performance true or false I am think t
asked on November 20, 2014 
phisecs
.: A 5.0 kg block is moving with constant velocity down a rough incline plane. The coefficients of static and kinetic friction between the block and the incline are 0.25 and 0.20, respectively. What is the inclination angle of the incline plane?
asked on March 24, 2014 
phisecs
A car travels in a straight line at 67 km/h for 1 h and at 106 km/h for 2 h. How far does it travel?
asked on February 18, 2014 
geometry
the perimeter of a rectangle is 72. the base is 3 times the height find the area of the rectangle
asked on October 3, 2013 
Math
Let p>q>0 with p+q = 1 and a = q/p < 1. Let X_n denote the random walk with transitions X_{n+1} = CASE 1: X_n + 1 with probability p and CASE 2: X_n  1 with probability q. For i â‰¥ 0, we set u_i = P(X_n = 0 for some n â‰¥ 0X_0 = i). Give the
asked on September 7, 2012 
Calculus
Write the first four nonzero terms and the general term of the Taylor serires for f about x=0. f(x)=2x/(1+x^2) I feel that I'm doing this wrong because finding the derivatives of f(x) look really messy. Can you please show me the steps? Thanks in advance!
asked on February 9, 2012 
Calculus
Integrate (1/2)sin(x^(1/2))dx. I've tried using usubstitution, with u=sin(x^(1/2)). du would then = ((1/2)x^(1/2))(cos(x^(1/2))). As you can see, this only make the problem more complicated. I don't get what to do. Thank you in advance!
asked on January 2, 2012 
Calculus
Integrate dx/xlnx. What method am I supposed to use? I'm totally lost.
asked on January 2, 2012 
Calculus
How do I integrate (e^(3/x))/(x^2) from 1 to 3. I understand how and why I need to do usubstitution, with u=3/x and so dx=(3 du)/x^2. After plugging (3 du)/x^2 in for dx, I get a really messy problem that I don't know how to finish. Can you please
asked on November 21, 2011 
Calculus
How do I determine the area of a region bounded by a function and the xaxis if given y=cosx and interval is [0,ð/2]. This has to do with the Fundamental Theorem of Calculus. Thanks in advance!
asked on October 27, 2011 
Euro history
What is the immediate cause of WWII? Is it Germany's invasion of Poland? I can't remember.
asked on April 22, 2011 
Math
I need some help with this question. (5/x2) = (6/x+6) + {29/(x2)(x+6)} I don't know how to solve this. Can someone help me figure this out? Thanks.
asked on September 2, 2010 
accounting
The following information is for X Company for 2009: Direct materials purchased $ 36,484 Direct materials used 34,013 Direct labor 14,439 Overhead 25,464 Work in Process, January 1, 2009 4,118 Finished Goods, January 1, 2009 2,326 Work in Process, December
asked on February 19, 2010 
chemistry
How many moles are there in 23.6g Ag?
asked on January 20, 2010

Health
W
posted on February 27, 2019 
5th grade math
e
posted on January 18, 2019 
science(check answers)
1 is false
posted on October 19, 2018 
science(check answers)
Thx for the answers
posted on October 16, 2018 
Science
Help
posted on October 8, 2018 
Physics
Not nice it is not correct answer please check it again
posted on September 2, 2018 
Physics
Not nice
posted on September 2, 2018 
Physics
Not nice answer
posted on September 2, 2018 
physics
16.05 N
posted on September 16, 2017 
Science help
desertification
posted on June 16, 2017 
writing english
I think write teacher is a !@#$%^&
posted on June 15, 2017 
math
♥️ Is correct I got a 5/5
posted on March 28, 2017 
Physics
Decrease to oneninth
posted on March 7, 2017 
Global Studies
Ann Onymous is right.
posted on January 10, 2017 
ECE
oral
posted on November 28, 2016 
Science
Cotton
posted on May 10, 2016 
Human Sexuality
c
posted on November 29, 2015 
Child Developmental
The second question b or c
posted on October 2, 2015 
Child development
Thanks so for the help.
posted on October 2, 2015 
ADHD
Okay can you please help me?
posted on October 2, 2015 
Physics
Wa
posted on September 1, 2015 
statistics
0.0067
posted on May 5, 2015 
School
Small muscle usually occurs before large muscle. I am think false.
posted on November 20, 2014 
phisecs
In a collision, an automobile of mass 826 kg stops with constant acceleration in 20 m from an initial speed of 17 m/s. What is the acceleration of the car in m/s
posted on March 31, 2014 
phisecs
thank you for helping me , but i couldn't find similar question at the bottom or in the search button , could you please give me the link to it . thank you soo much
posted on February 21, 2014 
phisecs
279 thanks
posted on February 18, 2014 
w
does that mean 22 people of every 100 that aplky get accepted
posted on October 2, 2013 
Physics
5A doesn't seem to work
posted on June 17, 2013 
Physics
22.8
posted on June 4, 2013 
Physics
anyone get #6???
posted on May 27, 2013 
Physics
anyone get #6
posted on May 27, 2013 
Physics
anyone????
posted on May 27, 2013 
Physics
anyone get this
posted on May 8, 2013 
Physics
c = 0.00448571428571 d = 0.00897142857143 do you know lightly damped circuit or RC circuit
posted on May 8, 2013 
Physics
heeeelp
posted on May 8, 2013 
Physics
formulas for b and c anyone?
posted on May 8, 2013 
insurance prep
Where i can find information about blocks 18 and 19
posted on July 7, 2012 
4th grade limericks
So fat and could glow
posted on May 30, 2012 
Calculus
Thank you! That was helpful :)
posted on February 9, 2012 
Calculus
awesome! Thanks Damon ;D
posted on January 2, 2012 
Calculus
very cool. Thanks, both of you! Does wolfram alpha give steps for all integration problems?
posted on January 2, 2012 
Calculus
thanks! that was really helpful ;)
posted on December 14, 2011 
Calculus
Thank you! Now I understand that I should've multiplied by y instead of moving the whole "2/y (dy/dx)" to the other side of the equation and then factor the dy/dx out. I can't believe how such a simple manuever can make the problem so much easier to solve.
posted on November 30, 2011 
Chemistry
change grams to moles using the periodic table then use this equation molarity= moles of solute/liters of solution
posted on April 22, 2011 
algebra
Rewrite the equation to standard form. 6x5y=15 (6/5)xy=3 y=(6/5)x3 The coordinates for y intercept is always in the (0,_) format. Yintercept is what is added or subtracted. The coefficient on x (number multiplied to x) is slope. slope=6/5
posted on April 22, 2011 
Math
when x=10, y=17 when x=50, y=97 when x=100, y=197
posted on April 22, 2011 
Math
XY  0(3) 11 2(1) 33 4(5) 57 y=2x3
posted on April 22, 2011