# Piper

Popular questions and responses by Piper
1. ## 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?

2. ## 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

3. ## 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

4. ## math

solve the initial value problems: 1- dq/dz = 2 + sinz, q(0)=5 2-dy/dx = (x^2 -2)x, y(2)=4 3-dy/dx = 4e^5^x + x, y(0)=4 4- dy/dx 3x + 2, y(3)= 2

5. ## geometry

Quadrilateral JKLM is a rhombus. The diagonals intersect at N. If angle KNJ equals 8x + 6, find the value of x

6. ## 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

7. ## 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?

8. ## 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?

9. ## 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

10. ## 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

11. ## chem

How many molecules of (CH3)2NH are needed to react completely with 2.00mg of H2C2O4? Help i don't understand this process!

12. ## Physics

In 1926, Johnny Weissmuller set the men’s world 400.0-m 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?

13. ## 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 10-19 J. If light with a wavelength of 256 nm impinges on a piece of calcium,

14. ## 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

15. ## 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

16. ## 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

17. ## 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.

18. ## 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?

19. ## 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.

20. ## 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

21. ## Chemistry

The Ka of a monoprotic weak acid is 3.29 × 10-3. What is the percent ionization of a 0.176 M solution of this acid?

22. ## 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?

23. ## 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.

24. ## 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.

25. ## 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

26. ## chem

How many molecules of (CH3)2NH are needed to react completely with 2.00mg of H2C2O4? Help i don't understand this process!

27. ## 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

28. ## 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

29. ## 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

30. ## 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

31. ## Math

What is 0.0185 as a fraction and a percent

32. ## 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?

33. ## 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

34. ## math

what is the base of a parallelogram with the height 6and 5 eighths feet and area of 26 and a half

35. ## 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 10-19 J. If light with a wavelength of 256 nm impinges on a piece of calcium,

36. ## 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)?

37. ## 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

38. ## chem

How many molecules of (CH3)2NH are needed to react completely with 2.00mg of H2C2O4? Help i don't understand this process!

i need help on a few questions from the book October sky/rocket boys so here they are: -name of the rockets (through chapters 1-8) and why did they name them that ? -what does sonny name his new launching site -who is valentine -why is the football team so

40. ## 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

41. ## 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)

42. ## chem

How many molecules of (CH3)2NH are needed to react completely with 2.00mg of H2C2O4? Help i don't understand this process!

43. ## 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

44. ## 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?

45. ## MATH (CALCULUS) PLZ HELP

A common problem encountered by the oil industry is to determine the most cost-effective 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.

46. ## 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

47. ## calculus

solve the initial value problems: 1- dq/dz = 2 + sinz, q(0)=5 2-dy/dx = (x^2 -2)x, y(2)=4 3-dy/dx = 4e^5^x + x, y(0)=4 4- dy/dx 3x + 2, y(3)= 2

48. ## math

1-show that 1-x/2 is the tangent line approximation to 1/ sqrt of 1+x near x=0 2-what is the local linearization of e^x^2 near x=1 3-find the tnagent line approximation of 1/x near x=1

49. ## language arts

I cant find the ourspace website, I need for this evenings home work I have search several search engines...Any suggestions please

50. ## Chemistry

At what speed must a human weighing 150.0 lb be traveling in order to have a wavelength at 650 nm?

51. ## 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

53. ## Math

Write an equation in point slope form y-y1=m(x-x1) 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.

54. ## 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

55. ## social studies

why do they call the presidents wife the first lady

This is actually 10th grade chemistry and I can't figure it out either

posted on April 10, 2020
2. ## World History

It’s B

posted on April 8, 2020
3. ## 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
4. ## math

17 1/16

posted on November 18, 2019
5. ## Math

idkidkidkidkidkidkidkidkidkidkidkidkidkidkidkidkikidkidkidkidkidkidkkidkdiidkik

posted on November 14, 2019
6. ## 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
7. ## MATH 156

I don’t get it?🤯

posted on September 22, 2019
8. ## History

B? Correct me if im worng

posted on January 29, 2019
9. ## LA

posted on October 4, 2018
10. ## Algebra

1. C 2. C 3. A 4. B 100% I hope this helped! :)

posted on May 18, 2018
11. ## math

posted on May 8, 2018
12. ## math

you subtract then? 320-40=280?

posted on August 17, 2017
13. ## math

2. 0.6=60% 1. i think you should divide? 125?

posted on August 17, 2017
14. ## writing skills

let me proof it again Ms.Sue

posted on June 28, 2016
15. ## writing skills

thanks Sue :)

posted on June 28, 2016
16. ## writing skills

oh um begin the sentence with be sure that you ...... then the answers 1-5 should be the next words. before applying for any job.

posted on June 28, 2016
17. ## writing skills

posted on June 28, 2016
18. ## writing skills

okay :(

posted on June 28, 2016
19. ## writing skills

ooh the real answer is 5

posted on June 28, 2016
20. ## Math

Can Someone give a more detailed explanation

posted on November 19, 2015
21. ## Math

I do not know how to do the hint.

posted on April 6, 2015
22. ## 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 280-168 = 84 women = 168-140 = 28 168+84+28 = 280

posted on March 20, 2015
23. ## math

you will need \$4.28

posted on March 20, 2015
24. ## 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

It took 6.

posted on March 20, 2015
26. ## maths financial

R4976 per month.

posted on March 19, 2015
27. ## Physics

Thank you

posted on June 18, 2014
28. ## Algebra

5 a steady process 6. m is the slope

posted on March 31, 2010
29. ## government

main purpose for which the delegates are chosen.

posted on January 22, 2009