1. math

In Philadelphia the number of hours of daylight on day t (where t is the number of days after Jan. 1) is modeled by the function L(t)= 12+2.83sin(2pi/365(t-365)) A) Which days of the year have about 10 hours of daylight? B) Which days of the year have more

2. math

John must mount a box which is 12 5/8 inches wide. He wants to leave 7 1/2 inches on each side of the box. How much space across will John need?

3. Physics

A gas with initial conditions p_i, V_i, and T_i expands isothermally until V_ f=6 V_i. What are (a) T_f and (b) p_f? in terms of T_f/T_i and P_f/P_i First I don't understand what this is saying at all. And Second I need to know how to solve it.

4. mathematical modeling

Person A opens an IRA at age 25, contributes \$2000 per year for 10 years, but makes no additional contributes thereafter. Person B waits untill age 35 to open an IRA and contributes \$2000 per year for 30 years. There is no initial investment in either

5. Math

There are 150 green marbles and 100 yellow marbles in a bag that contains 250 marbles. If only yellow marbles are added to the bag so that the probability of randomly drawing a yellow marble from the bag becomes 3/5, how many yellow marbles are in the bag?

6. algebra

Volume of a Box (Refer to the preceding exercise.) A box is constructed from a square piece of metal that is 20 inches on a side. (a) If the square corners of length x are cut out, write a polynomial that gives the volume of the box. (b) Evaluate the

7. Chemistry

Hydrazine, N2H4 can be made (on paper) by reaction of molecular nitrogen and molecular hydrogen, 2 H 2 ( g ) + N 2 ( g ) --> N 2 H 4 ( g ) and suppose that the equilibrium constant Kp has the value 1×10^–3. (a) A stoicheometric mixture of H2 and N2 is

8. Physics

How do I determine the horizontal distance traveled by water passing through a hole of a punctured water bottle. You must use bernoulli's and Kinematics, and find delta x in term of h and y. ( y = the height of water inside the bottle , h = the height of

9. algebra

Volume of a Box A box is constructed by cutting out square corners of a rectangular piece of cardboard and folding up the sides. If the cutout corners have sides with length x, then the volume of the box is given by the polynomial A box is constructed from

10. Managerial Economics

Explain why the cost structure associated with many kinds of information good and services might imply a market supplied by a small number of large firms. (At the same time, some Internet businesses such as grocery home deliveries have continually suffered

11. Science

Carbon-14 has a half-life of about 5,600 years. Archaeologists analyze a piece of wood found at an ancient village site and determine that, of he initial 100 grams of Carbon-14 in the wood, onl 3.125 grams are left. How old is the wood?

12. math

a particle M oscillators (that is, moves back and forth) in a straight line along the horizontal axis. the position of M is given by: s(t) = 4 + 2 sin(2t) (1) Find the velocity (v) and acceleration (a) functions. (2) Find the initial position, initial

13. math\

2. A data set consists of a set of numerical values. Which, if any, of the following statements could be correct? a. There is no mode. (True or False) b. There are two modes. (True or False) c. There are three modes. (True or False)

14. Transcription

I'm on the fence about apostrophe or not in the following sentence. The possessive is not coming immediately before a noun or gerund; however, the English does belong to the gentleman. I realize a noun can show ownership to a noun that may have an

15. Physics

Clap your hands and estimate the energy and power released as sound waves. I know Kinetic energy= 1/2*m*v^2 and Power is KE/t but how do I find the velocity of the sound wave made from clapping my hands? and for the mass do I use the mass of my hands?

16. ALGEBRA 117

1. The cost, in millions of dollars, to remove x % of pollution in a lake modeled by C= 3,000/300-3x. Please note: x is in percent, not decimal form. a. What is the cost to remove 75% of the pollutant? b. What is the cost to remove 90% of the pollutant? c.

17. statistics

1. Find the mean, median, and range for each of the two data sets? 2. Find the standard deviation using the rule of thumb for each of the data sets. 3. Compare the two sets and describe what you discover. The following data sets shows the ages of the first

18. calculus

Consider a gun fired from a tower 96ft above the ground. The angle of elevation of the gun is 60 degrees, and its muzzle velocity is 1600 ft/sec (also gravity in this equation is 32 ft/sec^2). a)When does the bullet hit the ground? b)Write a parametric

19. Algabra 1

Buying a Home For most people, buying a house is a great investment that can offer security in an uncertain world, but buying a house is also a commitment. Application Practice Answer the following questions. Use Equation Editor to write mathematical

A substance was tested for Impurity A using liquid chromatography. 2 determinations were performed. In the 1st chromatogram, Impurity A was not detected, i.e. no Impurity A peak was observed and in the 2nd chromatogram, Impurity A peak was observed with a

21. Matrices

Gaussian row elimination method: (i) x+3y+z=4 x-2y-2z=3 2x+y-z=9 (ii) x+2z+y=0 2x+y+z=6 3x+3y+2z=14

22. chemistry

A steel block has a volume of 0.08 m and a density of 7,840 kg/m. What is the force of gravity acting on the block ( the weight ) in water?

23. ALGEBRA 117

2. Biologists want to set up a station to test alligators in the lake for West Nile Virus. Suppose that the costs for such a station are \$1,400 for setup costs and \$4.00 to administer each test. a. Write an expression that gives the total cost to test x

24. Geometry

If AB=2x-5 and BC=x+1, then find AB.

25. math

3. Indicate whether each of the given statements could apply to a data set consisting of 1,000 values that are all different. a. The 29th percentile is greater than the 30th percentile. (True or False) b. The median is greater than the first quartile.

26. CALC

I did post it wrong. sin(4x)/sin(x)=4cos(x)cos(2x). Verify the identity, please explain!

27. Grammar MT

Yes, JISKHA, You are right, It is Crohn's disease. The key given in our MT books was wrong by some printing mistake. Thank You, Ms Sue and Writeacher.

28. General Chemistry

Analyze the properties of a sodium atom and a sodium ion. What are the differences in mass, stability, and reactivity that are caused due to the differences between the sodium atom and sodium ion?

29. Grammar MT

Hello Jiskha, Can you pls help me in proofreading the below text, few corrections I made, still wanted to know if any mistakes exists. Thank You in advance SUBJECTIVE: This established patient is a 65-year-old white mail seen for major depressive disorder

30. stats

Start with x = 100 and add four x values to make a sample of five data such that the standard deviation of these data equals 0.

31. Differential equation

find the solution of power series (2x^2-X^3)y''+(7x-6x^2)y'+(3-6x)y=0 near zero

make F(x)=3/x-11 vertical asymptote

33. Grammar MT

Hope I have done it correctly now. SUBJECTIVE: This established patient is a 65-year-old white male seen for major depressive disorder with anxiety features. He has been prescribed Prozac 30 mg p.o. daily and BuSpar 20 mg p.o. b.i.d. The patient has

34. trig

Find the smallest positive value of x(in degree) for which tan(x+100°)=tan(x+50°)*tanx*tan(x-50°)

35. Grammar MT

Thank you, I have checked it is Crohn disease not Crohn's disease. as per medical transcription editing is concerned. Your adivce is very important to me. Jiskha is a very great help to many students like us, who's second language is english.

36. chemistry

how can I prepare sebacoyl chloride from sebacic acid with excellent yield?

before writing a recommendation report to the ceo, dee and carlos distribute a survey to everyone in their company to determine which new benefits employess are most interested in. what part of the wrting process does this activity represent?

38. calc

sin(4x)/sin(x)=4cos(x)cos(x) verify the identity

39. Finance

Clanton Company is financed 75 percent by equity and 25 percent by debt. If the firm expects to earn \$30 million in net income next year and retain 40% of it, how large can the capital budget be before common stock must be sold?

40. math

Having a problem with part of my question... 1. You have recently found a location for your bakery and have begun implementing the first phases of your business plan. Your budget consists of an \$80,000 loan from your family and a \$38,250 small business

41. Gen. Chemistry

Compare the properties of elements and compounds. Give two examples of each, including one example that exists in the human body. Explain the atomic nature of one element and one compound found in human body.

42. cja/393

the relationship between early ethnic or racially organized crime groups and contemporary youth gangs.

43. maths

Every day, a bakery owner buys either butter(B) or ghee(G).The type of item purchased in consecutive days is to be recorded.List the sample space.If a different type of item is purchased than in the previous day, we say that there is a switch.Let X denote

44. Maths

The diameter of a ball bearing is to have an averageof 2.0 Cm. A random sampling of 10 bearings is selected every hour to check the diameters. The sample selected at 9 a.m gave the following measurements: 2.02, 2.04, 2.00, 1.98, 2.04, 2.04, 2.00, 2.02,

45. Math

Which of the following numbers is between 1/8 and 1/4? PLEASE EXPLAIN (A)0.08 (B)0.11 (C)0.13 (D)0.25 (E)0.40

46. statistic

The area under a normal curve distribution is

47. Health care

You are a new administrator at a hospital, the icu & er are suffering a shortage of respiratory therapists, you need to gather information for a meeting with them, what information do you need before the meeting? develop a tactical plan, what are the major

48. Algebra

1. Many people know that the weight of an object varies on different planets, but did you know that the weight of an object on earth also varies according to the elevation of the object? In particular, the weight of an object follows this equation: w=Cr -2

49. basic electrical engineering

a battery havibg an emf of E volt and internal resitance .1ohm is connected across the treminals A and B. Calculate the value of E inorder that the power dissipated in the 2 ohm resistoe is 2 watt

50. Chemistry

Help :) I got this Chem homework to research on the Taxonomy of Living Things and on the species to kingdom. Anyone can help where I can find this? :) Thank you

51. Grammar MT

Thank you, so much, I am sorry I forgot it is White male not mail. I over looked this part as I was giving my exam unit test. Thank you so much again

52. Math

Sigourney Weaver's average rate going uphill was 80% of her average rate going downhill over the same route, and it took Sigourney Weaver 10 minutes longer to go up the hill than to go down the hill. What was the total number of minutes Sigourney Weaver