Piper
Popular questions and responses by Piper
Chemistry
Magnesium has three stable isotopes: 24Mg, 25Mg, 26Mg. The relative abundance of 24Mg is 79%. What are the relative abundances of 25Mg and 26Mg?
asked on February 3, 2017 
Physics
1. A rabbit and a turtle are practicing for their big race. The rabbit covers a 30.0 m practice course in 5.00 seconds; the turtle covers the same distance in 120 seconds. If the actual race is run on a 96.0 m course, by how many seconds will the rabbit
asked on June 18, 2014 
Math
With time, t, in minutes, the temperature, H, in degrees Celsius, of a bottle of water put in the refrigerator at time t=o is given by H = 4 + 16e.02t How fast is the water cooling initially? After 10 minutes? Include units in your answer
asked on April 8, 2010 
math
solve the initial value problems: 1 dq/dz = 2 + sinz, q(0)=5 2dy/dx = (x^2 2)x, y(2)=4 3dy/dx = 4e^5^x + x, y(0)=4 4 dy/dx 3x + 2, y(3)= 2
asked on April 19, 2010 
geometry
Quadrilateral JKLM is a rhombus. The diagonals intersect at N. If angle KNJ equals 8x + 6, find the value of x
asked on December 16, 2011 
Algebra
Word Problems: 1. A farmer has 2400 feet of fencing and wants to fence off a rectangular field that borders a straight river. If he needs no fence along the river, what are the dimensions of the field that he can fence with the largest area? Find the area
asked on August 13, 2014 
Chemistry
A mixture consisting of 1 mol of H2O(g) and 1 mol CO(g) is placed in a 7 L reaction vessel at 800 K. At equilibrium, 0.369 mol CO2(g)is present as a result of the reaction CO(g) + H2O(g)⇀↽CO2(g) + H2(g).What is Kc at 800 K?
asked on January 23, 2020 
Physics
An airplane takes off at 9:00 A.M. and flies at 300. km/h until 1:00 P.M. At 1:00 P.M. its speed is increased to 400. km/h, and it maintains this speed until it lands at 3:30 P.M. What is the airplane’s average speed for the entire flight?
asked on June 16, 2014 
Math
Explain in a variety of ways how you can distinguish the exponential function f(x)=2^x from the quadratic function f(x)=x^2 and linear function f(x)=2x. (Hint: Compare the rate of change using finite differences in table of values; identify a constant
asked on April 6, 2015 
Chemistry
A 1.000 L vessel is filled with 1.000 mole of N2 ,2.000 moles of H2, and 3.000 moles of NH3.When the reaction N2(g) + 3 H2(g)⇀↽2 NH3(g) comes to equilibrium, it is observed that the concentration of NH3is 2.12 moles/L. What is the numerical value of
asked on January 23, 2020 
chem
How many molecules of (CH3)2NH are needed to react completely with 2.00mg of H2C2O4? Help i don't understand this process!
asked on June 18, 2012 
Physics
In 1926, Johnny Weissmuller set the men’s world 400.0m swimming record in 4.00 min, 57.0 s. In 1966, Martha Randall set the women’s record in 4.00 min, 38.0 s. By how many meters would Martha have been beaten Johnny if they had raced each other?
asked on June 15, 2014 
Chemistry
The photoelectric work function of a metal is the minimum energy needed to eject an electron by irradiating the metal with light. For calcium, this work function equals 4.34 x 1019 J. If light with a wavelength of 256 nm impinges on a piece of calcium,
asked on February 4, 2017 
math
The average cost per item, C, in dollars, of manufacturing a quantity q of cell phones is given by C= (a/q) + b where a and b are positive constants a.Find the rate of change of C as q increases. What are its units? b. Currently, 5000 phones are being made
asked on April 8, 2010 
writing skills
Do your homework before applying for any job. If you rewrote sentence 5 beginning with Be sure that you the next words should be 1 got done your homework 2 got your homework done 3 had done your homework 4 did your homework 5 have done your homework answer
asked on June 28, 2016 
math
The average cost per item, C, in dollars, of manufacturing a quantity q of cell phones is given by C= (a/q) + b where a and b are positive constants a.Find the rate of change of C as q increases. What are its units? b. Currently, 5000 phones are being made
asked on April 7, 2010 
english
Choose the sentence that has a subject complement. A. The day ended with many surprises. B. I felt much better. C. The nurse felt my pulse. D. We can't leave without seeing her. I think it's B.
asked on March 20, 2014 
chemistry
What is the pH of a solution formed by mixing 400 mL of 0.025 M HCl with 600 mL of 0.015 M NaOH?
asked on May 2, 2012 
Trig  check my answers plz!
1. (P 15/17, 8/17) is found on the unit circle. Find sinΘ and cosΘ Work: P= (15/17, 8/17) cosΘ = a value P = (a,b) sinΘ = b value Answer: cosΘ = 15/17 sinΘ = 8/17 2. Should the triangle be solved beginning with Law of Sines or Law of Cosines.
asked on February 3, 2009 
writing skills
You think using a dictionary is hard, _____________________________________ imagine ________ how difficult it was to compile the first dictionary of English. Which of the following is the best way to write the underlined portion of this sentence? If you
asked on June 28, 2016 
Chemistry
The Ka of a monoprotic weak acid is 3.29 × 103. What is the percent ionization of a 0.176 M solution of this acid?
asked on September 27, 2012 
chemistry
What is the pH of a solution formed by mixing 400 mL of 0.025 M HCl with 600 mL of 0.015 M NaOH?
asked on May 10, 2012 
Math
Laura bought 24 pounds of sugar for $10. How many dollars did she pay per pound of sugar? If necessary, round your answers to the nearest hundredth. >> I got the answer 0.41 or 2.4. It says it is wrong.
asked on November 30, 2016 
Physics
Carlo drives his car for a picnic by first going 105 km north to pick up his girlfriend and then 120.0 km east to reach the picnic groove. The whole trip takes 135 min. Calculate (a) Carlo’s average speed and (b) average velocity.
asked on June 17, 2014 
math
1. With time, t, in minutes, the temperature, H, in degrees Celsius, of a bottle of water put in the refrigerator at time t=o is given by H = 4 + 16e.02t How fast is the water cooling initially? After 10 minutes? Include units in your answer
asked on April 7, 2010 
chem
How many molecules of (CH3)2NH are needed to react completely with 2.00mg of H2C2O4? Help i don't understand this process!
asked on June 19, 2012 
Math
a carpenter has several boards of equal length. he cuts 3/5 of each board. After cutting the boards, the carpenter notices that he has enough pieces left over to make up the same length as 4 of the original boards. How many boards did the carpenter start
asked on February 8, 2016 
Physics
To qualify for the finals in a racing event, a race car must achieve an average speed of 225 km/h on a track with a total length of 1.4 km. If a particular car covers the first half of the track at an average speed of 205 km/h, what minimum average speed
asked on June 15, 2014 
writing skills
When you are told time after time that there are no jobs. And it is time _____________ for some creative thinking and acting. Which of the following is the best way to write the underlined portion of these sentences? If you think the original is the best
asked on June 28, 2016 
Math
1. A man has 22 feet by 26 feet rectangular lot that he will use for planting. He wants to build a brick of walkway of uniform width on the border of the lot. If the man wants to have 396 square feet of ground left for planting, how wide should he build
asked on August 17, 2014 
Math
What is 0.0185 as a fraction and a percent
asked on April 25, 2013 
Math
Victor bought a brand new car for P750,000. If the value of the car depreciates 20%per year, what will it be worth during the fourth year?
asked on June 18, 2014 
WRITING SKILLS
When you are in school, almost any subject seems a potential area for a good job. What correction should be made to this sentence? 1 replace your are with one is 2 remove the comma after school 3 change Subject to subject 4 insert a comma after area 5 no
asked on June 28, 2016 
math
what is the base of a parallelogram with the height 6and 5 eighths feet and area of 26 and a half
asked on January 27, 2014 
Chemistry
The photoelectric work function of a metal is the minimum energy needed to eject an electron by irradiating the metal with light. For calcium, this work function equals 4.34 x 1019 J. If light with a wavelength of 256 nm impinges on a piece of calcium,
asked on February 4, 2017 
Math
Transform the graph of f(x)=3^x to sketch g(x)=3^−(x+1) −2. Show table of values and each transformation clearly to get full marks. (15,marks)?
asked on April 6, 2015 
Physics
On the way to class, you walk north and then west such that your resultant displacement is 290 m in a direction 250 west of north. Your average velocity is 2.0 m/s in the same direction as the displacement. Calculate (a) your walking time and (b) your
asked on June 17, 2014 
chem
How many molecules of (CH3)2NH are needed to react completely with 2.00mg of H2C2O4? Help i don't understand this process!
asked on June 18, 2012 
English, Reading
i need help on a few questions from the book October sky/rocket boys so here they are: name of the rockets (through chapters 18) and why did they name them that ? what does sonny name his new launching site who is valentine why is the football team so
asked on April 20, 2014 
math
i have 2 problems. 1. Only 40% of the seats in a theater are occupied. The theater 320 seat. How many seats are occupied? 2. In one game, a football quarterback threw 20 passes and completed 12 of them. What percent of the passes were completed? while
asked on August 17, 2017 
Physics
A motorist drives for 150 km from City A to City B in 2.5 hr. He makes the return trip in 2.0 hr. Find (a) the average speed for each half of the trip, (b) the average velocity for each half of the trip, (c) the average speed of the entire trip, and (d)
asked on June 16, 2014 
chem
How many molecules of (CH3)2NH are needed to react completely with 2.00mg of H2C2O4? Help i don't understand this process!
asked on June 18, 2012 
Chem
In a titration process it takes 22.00 mL of nitric acid to neutralize 16.70 mL of 0.200 M calcium hydroxide solution. what is the balanced equation and what is the molarity of the acid. please explain
asked on June 13, 2012 
science
i need help with standard deviation and erro bars on graph, if i want to talk about my graph and mention the erro bars and what it means how do i do that?
asked on April 16, 2010 
MATH (CALCULUS) PLZ HELP
A common problem encountered by the oil industry is to determine the most costeffective route to connect various wells in an oil fertile area. The attached map is a copy of a section of a U.S. Geographical Survey contour map with a wetland area outlined.
asked on April 1, 2010 
math
math professor is thrown off the matthews bridges, height 240ft, by a disgruntled calculus class with an intitial upward velocity of 10ft/s a) assumign the acceleration dude to gravity is 32ft/s^2,find the macimum height of the professor. b) find the time
asked on April 20, 2010 
calculus
solve the initial value problems: 1 dq/dz = 2 + sinz, q(0)=5 2dy/dx = (x^2 2)x, y(2)=4 3dy/dx = 4e^5^x + x, y(0)=4 4 dy/dx 3x + 2, y(3)= 2
asked on April 19, 2010 
math
1show that 1x/2 is the tangent line approximation to 1/ sqrt of 1+x near x=0 2what is the local linearization of e^x^2 near x=1 3find the tnagent line approximation of 1/x near x=1
asked on March 31, 2010 
language arts
I cant find the ourspace website, I need for this evenings home work I have search several search engines...Any suggestions please
asked on August 31, 2011 
Chemistry
At what speed must a human weighing 150.0 lb be traveling in order to have a wavelength at 650 nm?
asked on February 5, 2017 
Physics
1. A person runs 800. m at an average speed of 6.00 m/s and then the next 800. m at an average speed of 8.00 m/s. Calculate (a) the total time of travel and (b) the average speed. 2. A boy kicked a can horizontally from a 6.5 m high rock with a speed of
asked on June 18, 2014 
SCIENCE
could you please help me on some information about this topic please. Ihave a presentation to do on this and i need scientific research or journals as references to add to my powerpoint. An Investigation of the Impacts of Current on Shoaling and schooling
asked on April 14, 2010 
Math
Write an equation in point slope form yy1=m(xx1) for a line containing the point (1,2) and has a slope of 3 Can someone explain how to do this problem. I'm having trouble with this.
asked on November 9, 2015 
math
a math professor is thrown off the matthews bridges, height 240ft, by a disgruntled calculus class with an intitial upward velocity of 10ft/s a) assumign the acceleration dude to gravity is 32ft/s^2,find the macimum height of the professor. b) find the
asked on April 20, 2010 
social studies
why do they call the presidents wife the first lady
asked on November 18, 2012

10th grade
This is actually 10th grade chemistry and I can't figure it out either
posted on April 10, 2020 
World History
It’s B
posted on April 8, 2020 
math
I thank This app so much I can cheat and I’m so happy because I suck at math
posted on November 19, 2019 
math
17 1/16
posted on November 18, 2019 
Math
idkidkidkidkidkidkidkidkidkidkidkidkidkidkidkidkikidkidkidkidkidkidkkidkdiidkik
posted on November 14, 2019 
Math
For which value of x must the expression 77x be further simplified? A) 13 B) 23 C) 29 D) 33
posted on September 27, 2019 
MATH 156
I don’t get it?🤯
posted on September 22, 2019 
History
B? Correct me if im worng
posted on January 29, 2019 
LA
@Finn Wolfhard I love your username!! I love Stranger Things/IT!
posted on October 4, 2018 
Algebra
1. C 2. C 3. A 4. B 100% I hope this helped! :)
posted on May 18, 2018 
math
The answer is 3 feet
posted on May 8, 2018 
math
you subtract then? 32040=280?
posted on August 17, 2017 
math
2. 0.6=60% 1. i think you should divide? 125?
posted on August 17, 2017 
writing skills
let me proof it again Ms.Sue
posted on June 28, 2016 
writing skills
thanks Sue :)
posted on June 28, 2016 
writing skills
oh um begin the sentence with be sure that you ...... then the answers 15 should be the next words. before applying for any job.
posted on June 28, 2016 
writing skills
did your homework ?
posted on June 28, 2016 
writing skills
okay :(
posted on June 28, 2016 
writing skills
ooh the real answer is 5
posted on June 28, 2016 
Math
Can Someone give a more detailed explanation
posted on November 19, 2015 
Math
I do not know how to do the hint.
posted on April 6, 2015 
math
If there were x people in all, then men = (3/4)(2/5)x = 3/10 x 3/5 x = 140 + (1  3/5  3/10)x = 140+x/10 6x = 140+x 5x = 1400 x = 280 check: 3/5 of 280 = 168 3/4 of 280168 = 84 women = 168140 = 28 168+84+28 = 280
posted on March 20, 2015 
math
you will need $4.28
posted on March 20, 2015 
Life orientation
Promotes socialism (bringing people together), which helps create a stronger bond between people Provides a building block for patriotism, which can involve cheering on and advocating ones own nation
posted on March 20, 2015 
math 5th grade
It took 6.
posted on March 20, 2015 
maths financial
R4976 per month.
posted on March 19, 2015 
Physics
Thank you
posted on June 18, 2014 
Algebra
5 a steady process 6. m is the slope
posted on March 31, 2010 
government
main purpose for which the delegates are chosen.
posted on January 22, 2009