# JC

Popular questions and responses by JC
1. ## Math

Algebra Riddle with PIZZAZZ "Did you hear about..."

2. ## Physics3

Two charged particles of equal magnitude (+Q and +Q) are ﬁxed at opposite corners of a square that lies in a plane (see ﬁgure below). A test charge −q is placed at a third corner. If F is the magnitude of the force on the test charge due to only one

3. ## Physics

A lawn mower has a flat, rod-shaped steel blade that rotates about its center. The mass of the blade is 0.65kg and its length is 0.55m. What is the rotational energy of the blade at its operating angular speed of 3450 rpm? If all of the rotational kinetic

4. ## history

Which identify protestant argument that challenge the sanctity and infallibility of the catholic papacy

5. ## chemistry

part B. would you expect the emissions to vary if metal flourides were used rather than metal chlorides?

6. ## trig

a tree growing on a hillside casts a 102-foot shadow straight down the hill. Find the vertical height of the tree if, relative to the horizontal, the hill slopes 15.0 degrees and the angle of elevation of the sun is 62.0 degrees.

7. ## Physics

A bullet is dropped into a river from a very high bridge. At the same time, another bullet is fired from a gun straight down towards the water. If air resistance is negligible, the acceleration of the bullets just before they strike the water A. is greater

8. ## electrostatic physics

2. At the point of fission, a nucleus of 235U that has 92 protons is divided into two smaller spheres, each of which has 46 protons and a radius of 5.9 × 10^-15 m. What is the magnitude of the repulsive force pushing these two spheres apart? The value of

9. ## physics

A cyclist in an Olympic race is moving in a circular track of radius 80 m with speed 72 km/h. He has to lean from the vertical approximately through an angle of... ANS: tan-1(1/2) How is tan-1(1/2) derived in this answer?

10. ## Physics

A wheel of radius R starts from rest and accelerates with a constant angular acceleration alpha about a fixed axis. At what time t, will the centripetal and tangential accelerations of a point on the rim have the same magnitude?

11. ## home economics

As part of the nation’s recovery from the Great Depression of the 1930s, the banking system was reformed in which of the following ways? A. The government paid off loans for large corporations. B. The Federal Reserve Banks were closed. C. Banks were

12. ## World history

what freedoms were the people of Napoleon's day willing to sacrifice

13. ## Chemistry

48.0 mL of Ca(OH)2 solution was titrated with 19.2 mL of 0.385 mL mol HNO3. Determine the molarity of the Ca(OH)2 solution.

14. ## electrostatic physics

Two charged particles of equal magnitude (+Q and +Q) are ﬁxed at opposite corners of a square that lies in a plane (see ﬁgure below). A test charge −q is placed at a third corner. If F is the magnitude of the force on the test charge due to only one

15. ## electrostatic physics

Four point charges are placed at the four corners of a square. Each side of the square has a length L. Find the magnitude of the electric force on q2 due to all three charges q1, q3 and q4 for L = 1 m and q = 1.55 C. Answer in units of N

16. ## Physics

A rock is thrown vertically upward with a speed of 11.0 from the roof of a building that is 70.0 above the ground. Assume free fall. In how many seconds after being thrown does the rock strike the ground? What is the speed of the rock just before it

17. ## precalc

Assume the function has only one x-intercept at the origin, and the point marked on the graph is located at (6,-3/5). The asymptotes are x=-4 and x=5. give the formula as a reduced rational function.

18. ## Physics

Two stones are thrown vertically upward from the ground, one with three times the initial speed of the other. Assume free fall. If the faster stone takes 9.00 to return to the ground, how long will it take the slower stone to return? If the slower stone

19. ## Physics

I have no idea!!! A river flows due south with a speed of 2.30 m/s. A man steers a motorboat across the river; his velocity relative to the water is 4.50 m/s due east. The river is 900 m wide. In which direction should the motorboat head in order to reach

20. ## Physics

A centrifuge is a common laboratory instrument that separates components of differing densities in solution. This is accomplished by spinning a sample around in a circle with a large angular speed. Suppose that after a centrifuge in a medical laboratory is

21. ## Physics

A rocket blasts off vertically from rest on the launch pad with an upward acceleration of 2.30 . At 10.0 after blastoff, the engines suddenly fail, which means that the force they produce instantly stops. How high above the launch pad will the rocket

22. ## college physics

An airplane is flying with a velocity of 240 m/s at an angle of 30.0° with the horizontal, as the drawing shows. When the altitude of the plane is 2.4 km, a flare is released from the plane. The flare hits the target on the ground. What is the angle è?

23. ## Physics

An ideal string passes over a fixed pulley and carries masses M1 = 12kg and M2 = 8kg tied at its end. Calculate the acceleration of masses and tension in the string when released (g=10m/s2) I know the answers are a = 2 m/s^2 T = 96 N But I don't know how

24. ## Language Arts - Writing

Can anyone suggest an animal that could be considered messy or disorganized, along with a complementary animal that would be associated with tidiness or neatness? ie: curious cat, wise owl, smart pig, sly fox. Thanks. The messiest creature, aside from man,

25. ## Physics

Given: 90m skid mark .50 coefficient of friction between the tires and skid mark How fast is the car moving when the brakes initially applied?

26. ## Physics1

Four point charges are placed at the four corners of a square. Each side of the square has a length L. Find the magnitude of the electric force onq2 due to all three charges q1, q3 and q4 for L = 1 m and all q = 1.55 C. Answer in units of N

27. ## Physics2

A particle of mass 47 g and charge 54 C is released from rest when it is 13 cm from a second particle of charge −15 C. Determine the magnitude of the initial acceleration of the 47 g particle. Answer in units of m/s2

28. ## Physics

the charges an coodinates of two points charges located in x-y palne are : q1=+3*10^-6 C ; x=+3.5 cm . y=+0,5 cm and q2=-4*10^ -6 C; x= - 2 cm y=+1.5 cm . (a)Find the electric potential at the origin(b)How much work must be done to locate these charges at

29. ## Physics

A cannonball is fired horizontally from a 240 -high cliff toward a vertical building 540 away with an initial velocity of 90.0 . When the ball will hit the building? A) 7.00 s B) 6.00 s C) less than 6.00 s D) more than 7.00 s If it's fired horizontally,

30. ## precalc

The x-intercepts are marked with points located at (5,0) and (-6,0), while the y-intercept is marked with point located at (0,3/2). The asymptotes are y=1, x=-5, and x=4. Give your formula as a reduced rational function.

31. ## physics

Vector A has a magnitude of 23 units and points in the positive y-direction. When vector B is added to A, the resultant vector A+B points in the negative y-direction with a magnitude of 15 units. Find the magnitude of B?

32. ## Math

The fourth term of arithmetic sequence is 18 and the sixth term is 28. Give the next three terms.

33. ## Physics

A thin condicting spherical shell of outer radius 20cm carries a charge of +3 muC. Sketch (a) magnitude of the electric field E and (b) potential V versus the distance r from the center of the shell.

34. ## Physics

A tennis ball on Mars, where the acceleration due to gravity is 0.379 of a and air resistance is negligible, is hit directly upward and returns to the same level 9.50 later. How fast was it moving just after being hit? The formula is the same as we use on

35. ## physics

a 150 grain .30-06 bullet has a mass of 0.01 kg and a muzzle velocity of 900 m/s. If it takes 1 ms(millisecond) to travel down the barrel, what is the average force acting on the bullet?

36. ## college physics

loft the ball with an initial speed of 15.0 m/s at an angle of 50.0° the horizontal. At this instant your opponent is 10.0 m away from the ball. He begins moving away from you 0.38 s later, hoping to reach the ball and hit it back at the moment that it is

37. ## Physics

A golf ball is hit into the air, but not straight up, and encounters no significant air resistance. Which statements accurately describe its motion while it is in the air? A.On the way up it is accelerating upward, and on the way down it is accelerating

38. ## Physics4

2. At the point of fission, a nucleus of 235U that has 92 protons is divided into two smaller spheres, each of which has 46 protons and a radius of 5.9 × 10^-15 m. What is the magnitude of the repulsive force pushing these two spheres apart? The value of

39. ## electrostatic physics

A particle of mass 47 g and charge 54 C is released from rest when it is 13 cm from a second particle of charge −15 C. Determine the magnitude of the initial acceleration of the 47 g particle. Answer in units of m/s2

40. ## Grammar

In the sentence "Let's walk around." Walk is the noun or the verb? And What is "Let's"?

41. ## algerbra

3x-2y=8 2x=2y=22 How i solve with substitution?

42. ## IWU

You are considering buying 27 silver coins that look alike, but you have been told that one of the coins is a lightweight counterfeit. Find the least number of weighings on a balance scale that you can use to be certain you have found the counterfeit coin.

43. ## electrostatic physics

An uncharged molecule of DNA (deoxyribonucleic acid) is 2.15 m long. The ends of the molecule become singly ionized so that there is a charge of −1.6 × 10^−19C on one end and +1.6 × 10^−19C on the other. The helical molecule acts like a spring and

44. ## college physic

a rifle that has been ‘sighted in' for a 91.4-meter target. If the muzzle speed of the bullet is v0 = 328 m/s, there are the two possible angles è1 and è2 between the rifle barrel and the horizontal such that the bullet will hit the target. One of

45. ## math

Let a(t), v(t) and s(t) be the acceleration, velocity, and position functions respectively of a particle. If a(t)=5cos(t/2)+sint and s(0)=0, v(0)=-5. How do i find the position function s(t)?? find s(t) as the second integral of a(t) s(t)= INTINT a(t) dt

46. ## chemistry

The boiling point of diethyl ether, CH3CH2OCH2CH3, is 34.500 °C at 1 atmosphere. Kb(diethyl ether) = 2.02 °C/m In a laboratory experiment, students synthesized a new compound and found that when 13.85 grams of the compound were dissolved in 283.2 grams

47. ## Physics

a small sphere whose m mass is 1.0 mg carries a charge q of 2.0*10^(-8)C. It hangs from a silk thread that makes an angle of 30 degrees with a large charged nonconducting sheet as in figure. Calculate the uniform charge density σ for the sheet

48. ## Physics

A brick is thrown upward from the top of a building at an angle of 30° to the horizontal and with an initial speed of 11 m/s. If the brick is in flight for 3.2 s, how tall is the building? ___m

49. ## statistics

a random sample of 100 college students is taken from the student body of a large university. assume that a population mean of 20 hours and a population standard deviation of 15 hours describes the weekly study estimates for the entire student body. About

50. ## chemistry

A 7.00 g sample of KCl is dissolved in 81.0 mL of water. The resulting solution is then added to 28.0 mL of a 0.790 M CaCl2(aq) solution. Assuming that the volumes are additive, calculate the concentrations of each ion present in the final solution.

51. ## Math

Calculate the monthly finance charge for the following credit card transaction. Assume that it takes 10 days for a payment to be received and recorded and that the month is 30 days long. Assume 365 days in a year. (Round your answer to the nearest cent.)

52. ## english

hi~i'm writing a paragraph about High Absenteeism from School. could you help me to correct the grammar and see whether my ideas relates to my tpoic or not. The topic of absenteeism in school can be approached from several angles due to its complexity.

53. ## Physics

At the instant the traffic light turns green, an automobile that has been waiting at an intersection starts ahead with a constant acceleration of 2.50 . At the same instant, a truck, traveling with a constant speed of 15.4 , overtakes and passes the

54. ## philosophy

what does this quote mean? "everyman, wherever he goes, is encompassed by a cloud of comforting convictions, which move with him like flies on a summer day" by Bertrand Russel. can somebody help me with this. thx

55. ## math

We fire a missile from ground level at 1750 ft/sec. at launch angle of 10 degrees. h(t) =-16t^2 + vot +h a. find a function for height as a function b. find a function for distance from launch point as a function of time. c. when will the missile reach max

56. ## Physics

An athlete starts at point and runs at a constant speed of 5.40 around a round track 250 in diameter Find the component of this runner's average velocity between points A and B. Find the component of this runner's average velocity between points A and B.

57. ## Physics

A 0.525 ball starts from rest and rolls down a hill with uniform acceleration, traveling 154 during the second 10.0 of its motion. How far did it roll during the first 4.00 of motion?

58. ## physics

An airplane flies 200 km due west from city A to city B and then 305 km in the direction of 30.0° north of west from city B to city C. (a) In straight-line distance, how far is city C from city A? ___km (b) Relative to city A, in what direction is city C?

59. ## Physics

Sorry for posting so many, but I just need to make sure I'm on the right track. Just need someone to check my working and answers. A rocket has a mass 3000kg. The fuel used in the rocket has an additonal mass of 500kg. At the launch, the rocket accelerates

60. ## criminal law

•Should the United States combine all the police agencies into one national police organization? Why or why not? •If you must consolidate the police, would you have to do the same to the criminal justice system? How would you create and establish such

61. ## chemistry,math

One liter of approximetely 0.25N HNO3 has been prepared. Upon titration it was found that 5.0 ml of the acid required 11.0 ml of 0.10N NaOH for neutrality. How much concetrated HNO3 at 15.8N must be added to one liter to make it exactly 0.25N?

62. ## chemistry

Buttermilk has 9 grams of protein and 12 grams of carbohydrate per cup (237ml). Estimate the concentration in mol/L of protein using the fact that the average protein is 300 amino acids long and the average amino acid has a mass of 110 amu

63. ## chemistry

how would you make one gram potassium chloride with barium chloride and potassium carbonate

64. ## math,chemistry

How much water should be added to 1 liter of 0.12N HCl to prepare exactly 0.1N HCl?

65. ## Physics

A rock dropped from a small bridge encounters no air resistance and hits the pond below 1.0 s later. If it had been thrown horizontally with a speed of 10m/s , then it would have hit the water A. more than 1.0s later, since it has a greater distance to

66. ## Geometry

The base of the prism is a rectangle with sides 13 m and 5 m in length. Find the lateral surface and surface area of the given prism.

67. ## physics

The water skier in the figure is at an angle of 35degree with respect to the center line of the boat, and is being pulled at a constant speed of 15m/s . 1)If the tension in the tow rope is 90.0 , how much work does the rope do on the skier in 30.0 ? 2)How

68. ## help

i need help solvin this quadratic equation 2x^2+x-6=0 1/3x^2+8x-3=0 Try to factor, then set the factors equal to 0 to find possible solutions for x. For the first one: 2x^2 + x - 6 = 0 Factors are: (2x - 3)(x + 2) = 0 Setting the factors equal to 0: 2x - 3

69. ## math

You are buying telephone equipment from a company whose prices are given in English Pounds currency. You need to purchase telephone equipment for 3 offices along with one complete switchboard system. Equipment for each office costs 100 Pounds, and the

70. ## chemistry

how much oxygen gas wil be produce from the decomosition of 50 grams of pottasium chlorate

71. ## college physics

A diver runs horizontally with a speed of 0.759 m/s off a platform that is 10.0 m above the water. What is his speed just before striking the water?

72. ## physics

A jet plane lands with a speed of 101 m/s and can accelerate at a maximum rate of -4.60 m/s2 as it comes to rest. (a) From the instant the plane touches the runway, what is the minimum time needed before it can come to rest? ___s b)What is the actual

73. ## Physics ( Thickness of a Spherical Shell)

Aluminum floater: A spherical shell with an outer radius R=2 cm is made of aluminum (mass density of Al is 2.7 g/cm3). How thick is the shell if the average density of the spherical object is exactly 0.5 g/cm3 ? Assume there is a vacuum in the hollow

74. ## chem

why do different compound have different colours in their visible emissions?

75. ## math,science,lab

One liter of approximetely 0.25N HNO3 has been prepared. Upon titration it was found that 5.0 ml of the acid required 11.0 ml of 0.10N NaOH for neutrality. How much concetrated HNO3 at 15.8N must be added to one liter to make it exactly 0.25N?

76. ## Chemistry

You are going to be provided with 1 0.50 g sample of magnesium oxide. Treatment of this sample with hydrochloric acid (HCl) will take all of the MAGNESIUM in the oxide and change it into magnesium chloride, MgCl2 You will add 100 ml of 1.0 M HCl to the

77. ## history

i have a history document analysis assignment. For this assignment, i need to discuss the respective worldviews of the British and the Chinese.however, i couldn't understand some of the details after i read the primary sources,"the search for modern China:

78. ## Math

In the arithmetic sequence -7, -4, -1, 2,..., what term is 44?

79. ## Physics

I'm having troubles with a few questions. A tennis ball is thrown vertically upwards. At the top of it's flight, it has: A. a zero speed and acceleration B. a zero speed and constant acceleration C. maximum speed and acceleration D. maximum speed but zero

80. ## mats

Factorise into prime factors: 2m^20-1/8

81. ## Society

What do you think a good third world city or a major city in a poor developing country would be a good one to write an urbanization report and trends on? I have to have a major city in the country? I just want advice if anyone knows what one would be good

82. ## chemistry

What is the pH of the solution created by combining 12.90 mL of the 0.10 M NaOH with 8.00 mL of the 0.10 M HC2H3O2?

83. ## algebra

-3x-5y=-6 6x+5y=-34 how do i solve this using elimination?

84. ## MHF4U

Solve: 12+4|6x−1|

85. ## physics

An airplane with a speed of 94.9 m/s is climbing upward at an angle of 63.2 ° with respect to the horizontal. When the plane's altitude is 743 m, the pilot releases a package. (a) Calculate the distance along the ground, measured from a point directly

86. ## chemistry

Calculate the pH in a 0.00500 solution of NaOH.

Is there hidden cost with pulley systems that reduce effort?

88. ## physics

a 15-kilogram box is dragged up an incline that is 8.0 meters long and makes an angle of 15 degrees with the horizontal. If the coefficient of friction between the box and the incline is .40, calculate the amount of work done by the applied force.

89. ## philosophy

if i define philosophy as an "Investigation of the nature, causes, or principles of reality, knowledge, or values, based on logical reasoning rather than empirical methods" what should i answer for the next question, such as "evaluate a definition of

90. ## chemistry

If the molecular weight of a protein is given as 90,000 are the units g/mol or simply g? I have seen mixed answers to this question. It will be 90,000 g/mol since 1 mol will have a mass of 90,000. But many simply drop the the mol and say the molecular

91. ## Physics

I have posted this one before, but the help I received went over my head... Firemen are shooting a stream of water at a burning building. A high-pressure hose shoots out the water with a speed of 21.0 m/s as it leaves the hose nozzle. Once it leaves the

Determine the Interval notation and Inequality notation of the absolute value notation: abs(x)>-5

Solve: 12+4|6x−1|

94. ## Statistics

Please advise how do I get the Regular % and the Cummulative % I just need one example other wise I will lose what's left of my mind. Defect Description Qty Improperly Sized 258 Bad Seam 153 Missing Buttons 67 Fabric Flaw 22 500

95. ## algebra

I am completely lost Here is one of my equations - "factor the given trinomial a2+3a+2

96. ## Chemistry

Determine how many mL of 0.102 mol NaOH solution is needed to neutralize 35.0 mL of 0.125 mol H2SO4 solution.

97. ## Anthropology

Ethnographic methods are to ethnological methods as: (Points : 1) the humanities are to the sciences. fieldwork is to laboratory experiments. description is to comparison. nature is to culture.

98. ## Physics

Consider a point charge with q= 1.5*10^-8 C. (a) what is the radius of an equpotential surface having a potential of 30 V?(b)Are surfaces whose potential differ by a constant amount (1,0 V) evenly spaced in radius?

99. ## college math

Find the distance of the shotcut and the distance of the long way for two locations. find the number of seconds saved ( 2.1 and 5.8) Approximate the are of the affected region (24 and 248 Sq Ft). find the average amount of oxgen saved per second saved