# Questions Asked onMarch 4, 2011

1. ## chemistry

Determine the delta H for the following reaction C3H4(g) + 2H2(g) --> C3H8(g)

Related Rates: Gas is escaping from a spherical balloon at the rate of 2ft^3/min. How fast is the surface area shrinking (ds/dt) when the radius is 12ft? (A sphere of radius r has volume v=4/3 pi r^3 and surface area S=4pi r^2.) Remember that ds/dt = ds/dr

3. ## Physics

A "swing" ride at a carnival consists of chairs that are swung in a circle by 12.0 m cables attached to a vertical rotating pole, as the drawing shows. (θ = 56.0°) Suppose the total mass of a chair and its occupant is 190 kg. (a) Determine the tension in

4. ## Pre-Calculus

A ladder leans leans against a building that has a wall slanting away from the ladder at an angle of 96 degrees with the ground. If the bottom of the ladder is 23 feet from the base of the wall and it reaches a point 52 feet up the wall, how tall is the

5. ## chemistry

how do I prepare 50% and 70% ethanol from 95% ethanol?

6. ## Physics-10

your friend says that the heavyweight champion of the world cannot exert a force of 50N on a piece of tissue paper with his best punch. the tissue paper is held in midair- no wall, no tricks. you?

7. ## chemistry

LiOH + CO2 ----> Li2CO3 + H2O 1. how I can balance the equation?

8. ## Math

Rolling 6 dice, what is the probability of rolling six of a kind?

A cart running on frictionless air tracks is propelled by a stream of water expelled by a gas-powered pressure washer stationed on the cart. There is a 1.00-m^3 water tank on the cart to provide the water for the pressure washer. The mass of the cart,

10. ## Chemistry

a sample of oil has a mass of 65g and a volume of 80.0ML. What is the specific gravity of the oil?

11. ## Physics-10

Two identical gliders slide toward each other on an air track. One moves at 1m/s and the other at 2m/s. they collide and stick. the combined mass moves at A. 1.5m/s B. 1/3m/s C. 1/6m/s D. 3/4m/s E. 1/2m/s which of this options is the right answer?

12. ## math

A rectangular painting has an area of 720 square inches. It is to be reduced by 1/6 scale factor. What is area of the miniature copy.

13. ## physics

A 1290-N uniform beam is attached to a vertical wall at one end and is supported by a cable at the other end. A W = 1920-N crate hangs from the far end of the beam. the angle going from the top of the beam o the brick wall is at 50.0 degrees. the angle

14. ## history

an important effect of the collective importance of wartime agencies was a.it set a valuable precedent of government activism in the economy b.it reduced the profits of America's largest corporations c.it started a downturn in the number of workers in

15. ## Math

The perimeter of triangle PQR is 78, PQ=18, triangle PQR ~ triangle STU, AND ST=6. What is the perimeter of triangle STU?

16. ## College Math 3

Lisa will rent a car for the weekend. She can choose one of two plans. The first plan has an initial fee of \$53.98 and costs an additional \$0.15 per mile driven. The second plan has an initial fee of \$67.98 and costs an additional \$0.10 per mile driven.

17. ## Vibrations and waves

A mass on a spring bobs up and down over a distance of 30cm from the top to the bottom of its path twice each second. What are its period and amplitude?

18. ## PRE CALC

1. solve tan36 degrees- tan2degrees/ 1+tan36 degrees tan 2 degrees as a single function. 2. Find the exact value of sin (α-β) if sina=4/5 and cos β= -9/41 terminal side of α lies in I and terminal side of β lies in III 3. If cosx=1/12 and sinx > 0,

19. ## physics

Two charges that are 2 meters apart repel each other with a force of 2 x 10-5 newton. If the distance between the charges is decreased to 1 meter, the force of repulsion will be A) 1 x 10-5 N B) 4 x 10-5 N C) 8 x 10-5 N D) 5 x 10-6 N

20. ## statistics

A manufacturing process has a 90% yield, meaning that 90% of the products are acceptable and the remainder are defective. If 4 of the products are randomly selected, find the probability that all of them are acceptable.

21. ## acct ch2

use information from T-account in exercise 2-15 to prepare general journal entries for each of the seven transaction a through g

22. ## physics

When the thigh is fractured, the patient's leg must be kept under traction. One method of doing so is a variation on the Russell traction apparatus. (See the figure.) Please place period in place of (dot) oi53(dot)tinypic(dot)com/2a0b7yx(dot)jpg If the

23. ## critical thinking

3. Definitions sometimes involve both denotative and connotative meanings. For example, the word talk might be defined with this denotative definition: “the verbal exchange of communication.” The associated meanings, or connotations, of talk might be

24. ## PHYSICS

Determine the equivalent capacitance between A and B for the group of capacitors in the drawing. Let C1 = 12 µF and C2 = 4.0 µF.

25. ## French HELP

I have to write a postcard in French. Im in grade 10, so my vocab isn't really up there. I have to include the date, tell where I am, and what celebration it is and how I like it. I have to describe the people I am with - Use adjectives. And report on the

26. ## Algebra

Say we want to determine how many people we can invite to a party for a given budget (\$ input). We want one snack and one soda for each person. The snack cost is \$1 and the soda cost is \$1 per can for \$2 total. How many people I can invite (the range)

27. ## word problem

Participants in a psychology experiment were able to memorize an average of M words in t minutes, where M = −0.001t3 + 0.1t2 Estimate the number of words memorizes after 14min where M=-0.001t^3 +0.1t^2

28. ## MUSIC

what is the definition of pop dance?

29. ## science

what is the definition of the word "dissolve"?

30. ## calculus

Please help with this. I submitted it below and was asked to clarify by Henry (hope this is clearer and thank you). I need the first derivative of f(x)=4(x+ sqrt (x(8-x)).And then the second derivative of this to show by the second derivative test that it

31. ## physics

2. Two equally charged balls, each of mass 0.10 gm, are suspended from the same point by threads 13 cm long. The balls come to rest 10 cm apart due to electrostatic repulsion. Determine the charge on each ball.

32. ## History

How did the Barbarians impact Europe? Can someone find a website to answer this?

33. ## physics

6. A charged particle remains stationary in an upwardly directed E field between two parallel charged plates separated by 2 cm. Compute the potential difference V between the plates if the particle has a mass of 4 x 10-13 kg and a charge of +2.4 x 10-18 C.

34. ## Math

Minimize C=7x+3y+4z 0≤x 0≤y 0≤z 100≤2x+3y+3z 120≤5x+2z Answer: Minimum value of C =?

35. ## science

can you give me a website on electric field?

36. ## Finance

A four-year TIPS bond promises a real annual coupon return of 4 percent and its face value is \$1,000. While the annual inflation rate was approximately zero when the bond was first issued, the inflation rate suddenly accelerated to 3 percent and is

37. ## History

I asked the history question below...Is they impacted on the population and language correct?

38. ## chemistery

suppose that "element a" has a valence number of 3 and "element b" has a valence number of 2. if the two elements combine, then when writing the formula for the resulting compound what subscript number will be given to "element b"?

39. ## Science

Identify two different types of green power. Identify a disadvantage and advantage of each type. Thanks Britt

40. ## physics

A computer is reading data from a rotating CD-ROM. At a point that is 0.032 m from the center of the disc, the centripetal acceleration is 111 m/s2. What is the centripetal acceleration at a point that is 0.070 m from the center of the disc?

41. ## Physics

A satellite is in a circular orbit around an unknown planet. The satellite has a speed of 1.70 104 m/s, and the radius of the orbit is 5.30 106 m. A second satellite also has a circular orbit around this same planet. The orbit of this second satellite has

42. ## chemisty

A 3.2 liter sample of gas is at 40.0oC and 1.0 atmosphere of pressure. If the temperature decreases to 20oC and the pressure decreases to 0.60 atmospheres, what is the new volume in liters?

43. ## cdemistry

A sample of gas collected at 21.0 oC and a pressure of 660.0 torr has a volume of 1.83 liters. What volume in liters will the gas occupy at 38.0 oC under a pressure of 500.0 torr?

44. ## Writing

How can I make these sentences better and more "personal"? 1) As a teenager, my priority is to go to school and do well in all my classes. Outside of the classroom I have many interests and hobbies, such as dancing, and helping out in my community. 2)

45. ## probabilities

Question: Five cards are dealt from standard deck of 52 cards, what is the probability of being dealt 3 kings? Here is what I have P(3 kings)= C(4,3) = 3 out of 4 kings being dealt C(48,2 = 2 out of remaning cards to complete 5 card deal C(52,5) = 5 cards

46. ## Chemistry

1. A cylinder of Xenon has a volume of 750. ml. At 25.0°C the cylinder has a pressure of 655 torr. How much Argon is present in the cylinder? a. 240. moles b. 0.0264 moles c. .315 moles d. 26.5 moles 2.If a 25 liter cylinder of gaseous ammonia at

47. ## chemistry

a 3.00mole sample of fluorine reacts with sodium bromide to produce how many grams of sodium fluoride?

48. ## chemistry

What is the pH of a 2.23 M HCHO2, formic acid, aqueous solution at 25 °C? ( Ka = 1.8E-4 )

49. ## Computer Science

I need to write a program to solve for the following: Suppose that the file USPRES.txt contains the names fo the frist 43 United States presidents and the file USSENATE.TXT contains the names of all former and present US Senators. Write a program with

50. ## Psychology

s2 pooled= 19/48 (10) + 29/48 (25)

A school yard teeter totter with a total length of 5.46 m and a mass of 35.9 kg is pivoted at its center. A 17.7 kg child sits on one end of the teeter totter. Where should a parent push with a force of 272 N in order to hold the teeter totter level?

52. ## health law

Which of the following is a characteristic of mediation? a. the court controls b. the parties remain in control c.a decision is imposed d.the mediator decides whos right

53. ## history

The main use of the Espionage Act was to A) harass nd arrest leaders of the antiwar movement ll) fund a massive intelligence operation in Europe C) arrest German-Arnerican spies D) promote unpopular industrial reguIations i think its d

54. ## chemistry

An unknown gas Q requires 2.17 times as long to effuse under the same conditions as the same amount of nitrogen gas. What is the molar mass (g/mol) of Q?

55. ## hcs/335

what is the social responsibility of children's hospital boston? isn't it to keep the safety and wellbeing of the patients and people who are injured and for the stem cell isnt it to help them getr sronger and stay alive?

56. ## ethics

What is the relationship and impact that scarce resources have on administrative ethics?

57. ## math

particles of mass 3m and 5 m hang one at each end of a light inextensible string which passes over a pulley.The system is released from rest with the hanging parts taunt and vertical.During the subsequent motion the resultant force exerted by the string on

I posted before ; Write equivalent equations in the form of inverse functions for a.)x=y+cos theta b.)cosy=x^2 my answers were a.) x= y+ cos theta cos theta = x-y theta = cos^-1(x-y) b.) cosy=x^2 cos(y) = x^2 y = Cos^-1(x^2) your post confused me a little.

60. ## music appreciation

The Baroque period began around the year ___?

61. ## Physics

To determine the location of his center of mass, a physics student lies on a lightweight plank supported by two scales L = 2.40 m apart If the left scale reads 278 N, and the right scale reads 116 N, calculate the student's mass. Calculate the distance

62. ## English Grammar

When we talk about staying somewhere, we use the preposition "at." (I am staying at the bar). If we talk about going somewhere, we use the preposition "to." (I am going to school). Why are we allowed to leave those prepositions out when we talk about home?

63. ## geometry

What is the perimeter of the isosceles triangle shown below? If necessary, round to the nearest hundredth.

A store specializing in collectible china and plates has decided to move into e-business. However, the store is unsure about how to get the word out about its new site and has hired your team to assist it. •Write a mini-marketing PowerPoint presentation

65. ## physics

A 0.50 kg ball that is tied to the end of a 1.2 m light cord is revolved in a horizontal plane with the cord making a 30° angle, with the vertical

66. ## physics

A 0.50 kg ball that is tied to the end of a 1.2 m light cord is revolved in a horizontal plane with the cord making a 30° angle, with the vertical

67. ## Word Problem

Suzie’s flower shop estimates that supplies costs for one month will be given by the polynomial 5x2 + 4x – 7. She estimates that utilities costs for one month is given by 8x + 8. Find and simplify an expression that would estimate Suzie’s total costs

68. ## chemistry

an aqueous solution of ammonia has 0.8% NH3 by weight.calculate the NH3 molarity

69. ## ELA

Can you check the essay below for any mistakes that can be fixed: “He who does not have the courage to speak up for his rights cannot earn the respect of others.” ~Rene G. Torres In the story “It Doesn’t Come Naturally”, by Danielle Compere,

How are the tactical plan and the goals related to long-term objectives (LTO) and Critical Success Factors in your experience

71. ## Physics

You design a roller coaster that has an initial drop from some height "h" followed by a loop and then the ride comes to a stop. If the loop of a circle with a diameter of 50 m, what is the minimum height you would need to make sure nobody falls out?

72. ## algebra

How do you do this kind of plroblem? What is the total balance due on a \$20000 loan at 5% for 6years if it is compounded semi-annually? (2x per year)

73. ## CALCULUS WXMAXIMA HELP PLEASE!

y=log(100493/40000x), y=atan(-100493/40000x), y=exp(100493/40000x) approximate the region bounded by the given curves. be sure to specify a range of x and y that results in a good picture of the region. you need two integral to represent the area

74. ## history

how did the united states expand so quickly in early 1800's?

75. ## Simply and Compound Interest

How do you do this kind of plroblem? What is the total balance due on a \$20000 loan at 5% for 6years if it is compounded semi-annually? (2x per year)

76. ## math algebra..help please urgent! due in 20mins

how to divide and simplify 12x^3-22x^2-44x-16/6x+4

77. ## Math

Farmer Mansfield wants to find whether the straight pipes are parallel. The distance from barn B to the north end of pipe 1 is 143 ft, and from there to the north end of pipe 2 is 42 ft. The distance from the barn to the south end of pipe 1 is 121 ft, and

78. ## literary

Are there any literary elements in the first part of Nineteen Minutes by Jodi Picoult??

79. ## Algebra

I need help to solve this problem by factoring: 2x^2-x-3=0

80. ## chemistry

how will u prepare 500g of aqueos solution which is 10% NaOH by mass?(%W/W)

81. ## math

algebra;40-20=50-_?

82. ## Physics

A 1220 kg car rounds a circular turn of radius 19.2 m. If the road is flat and the coefficient of static friction between the tires and the road is 0.66, how fast can the car go without skidding?

83. ## algebra

Given a quadratic equation in the form y = ax2 +bx +c , and four choices of graphs representing that equation, how can you tell which choices could be eliminated right away by looking at the equation and looking at the graphs and doing some minimal

84. ## physics

An airplane is flying horizontally with a speed of 1000 km/hr (278 m/s) when it drops a payload. The payload hits the ground 37 s later. (Neglect air drag and the curvature of the Earth. Take g = 10 m/s2.) (a) At what altitude H is the airplane flying?

85. ## science

Calculate the volume of distiled water to prepare 10%w/v solution of solute if 8g of the solute is to be used.

86. ## College Chemistry 2 - Equilibrium Constants/Conc.

The equilibrium constant for the reaction is 37 at a certain temperature. 2H2(g) + CO(g) CH3OH(g) If there are .0293 moles of H2 and .00353 moles of CH3OH at equilibrium in a 4.53-L flask, what is the concentration of CO? .....So far I have found: H2=

87. ## Math

How fast does a Ferrari FXX go compared to a Ferrari 575 GTC?

88. ## English

Can you please check these sentences for me please? Thank you. 1 Puritans was the name given to the more (most?) extreme Protestants within the Church of England. 2)Charles I's reign was characterized by the continuous conflict with the Parliament.

89. ## Geography

What events and factors have contributed to problems in South East Europe? IS there a website for this?

90. ## computer science

n insurance company wants to offer a new 5-year, level-term life insurance policy to recent college graduates. The policy will have a face value (the amount paid in case of death) of \$50,000. Normally, the company charges different premiums depending on

91. ## physics

what is the net force on a car cruising at a constant velocity on (a) a level ground and (b) going up a hill

92. ## social studies

is roanoke the first colony? or is jamestown the first colony?

93. ## critical thinking

A new campaign finance reform bill being considered by Congress would limit the amount of campaign contributions that political candidates can receive. However, a survey of candidates running for mayor, governor, and senate seats shows that not one of them

94. ## ICT

Give four methods of analyzing the existing system?

95. ## Physics

A chair with a mass of 21 kg is accelerated by a steady net force with a magnitude of 160 N. What is the magnitude of its acceleration?

96. ## geometry

Prove that all altitudes of a rhombus are conqruent

97. ## ICT

1) Name three methods of implementing a new system. 2)After the system is designed it will need to be implemented.Discuss methods by which the system could be implemented and give reasons why the systems analyst might choose one of the methods and not the

98. ## chemistry

Picking any two compounds, how do you describe which one has a higher dispersion force using the words Larger electron cloud and polarizability? Thanks:)

99. ## History

I was on the CIA world factbook and it said that interethnic warfare was a problem...what does that mean?

100. ## physics

Calculate the speed at the edge of a disc of radius 4 cm that rotates at the rate of 8 rev/s. Answer in units of m/s.

101. ## physics

Three small lamps are connected to a 24 V battery, as shown in the ﬁgure. Assume the battery is ideal (has no internal resistance and given in the ﬁgure) and the connecting wires have no resistance. Unlike most real bulbs, the resistances (given in the

102. ## physics

When a 250-kg boulder is acted upon by a net force of 1250 N, its acceleration is a1. When it is acted upon by a net force of 200 N, its acceleration is a2. What is the value of the ratio a1/a2?

103. ## Costs and Awards

Look for two programs that appeal to you at Education Planner and complete the chart below for each program. Program Name 1: Bachelor of Science in Pharmacy Degree Insitution: UBC IF Location: Point Grey Campus-Vancouver B.C Length of Program: Four years

Solve this trigonometric equation.give all positive values of the angle between 0deg and 360deg that will satisfy. Give any approximate value to the nearest minute only. 3 sin theta - 4 cos theta = 2

105. ## Geography

What 4 countries are in the heart of Europe? Some websites have 10 some have 1 or 2 but i can't find 4! Ugh! Can anybody help?

106. ## philosophy

philosophy of education is an application of formal philosophy to the field of education.discuss

107. ## English

What are the different types of intolerances not including food and allergies? For example racial, gender, sexual activity i.e homosexuals (what would be a name for that sort of intolerance?) and I can't think of anymore. Also what are some good short

108. ## Science

A person's height, eye color, and skin tone are all examples of?

109. ## Science

An animal has an allele for yellow eyes, but its eyes are grey. The allele for yellow eyes must be

110. ## Human Anatomy

(Part 2) Include the steps involved in transmitting the impulse “microscopically” through an individual neuron, from one neuron to another, and then from the neuron to the muscle fiber. (Part 3) Include in this the steps involved in the actual muscle

111. ## english

do u agree dat persistence is d major factor in success, and dat talent, genius, and education plays, at best secondary roles? Plan and write an essay in which u develop ur point of view on this issue.Support ur position with reasoning and examples taken

112. ## chemistry

Br2 + Cl2 ----> 2BrCl all estequiometicas con respecto a Cl2? cuantos moles de Cl2 se necesitan para formar 55g de BrCl? cuantos gramos de Br2 se necesitan para formar 38G de BrCl? Gracias,

113. ## physics

Two charged spheres are 8.00 apart. They are moved, and the force on each of them is found to have been tripled

114. ## English

do u agree dat persistence is d major factor in success, and dat talent, genuis and education play, at best secondary roles? Plan and write an essay in which u develop ur point of view on dis issue.Support ur position with reasoning and examples taken from

115. ## quemistry

Br2 + Cl2 ---> 2BrCl 1. FIND ALL THE REASONS ESTEQUIOMETRICAS WITH REGARD TO Cl2. 2. all the masses of Cl2 are needed to form 55g of BrCl. 3. all the grams of Br2 are needed to form 38g of BrCl. please I need help for this question for a homework. thanks

116. ## chemistry

Calculate .200 mol sodium phosphate in 10.0 ml of solution

117. ## math

Complete the following: (2 points per answer) Celestial Body Equatorial Diameter (km) Scientific Notation Earth 12,700 Moon 3.48 X 103 Sun 1,390,000 Jupiter 1.34 X 105 Mercury 4800 2. Theater ticket prices (in dollars) x years after 1997 are described by

118. ## Machanics

particles of mass 3m and 5 m hang one at each end of a light inextensible string which passes over a pulley.The system is released from rest with the hanging parts taunt and vertical.During the subsequent motion the resultant force exerted by the string on

119. ## math

what is the simplest form of 2 2/5?

120. ## statistics

what is the variance and standard deviation for the group of numbers: 28 27 48 52 77 29 30 31 60

121. ## chemistry

I need a problem: LiOH + CO2 ---> Li2CO3 + H2O 1. to balance the equation? 2. write the reasons estequiometricas with regard to Li2CO3? 3.how much do masses of Li2CO3 form if we add 37g of LiOHa to the Rxn? thanks

122. ## algebra 2

how do you solve x+2y=17 and 3x+6y=-5 to find out how many solutions it has?

123. ## Statistics

A student score 78 on his statistics test where the average score was 90 the the standard deviation was 7.

124. ## social studies

how does the federal governement impact our country?

125. ## statistics

im so confused! please help! 3. A car manufacturer is interested in conducting a study to estimate the mean stopping distance for a new type of brakes when used in a car that is traveling at 60 miles per hour. These new brakes will be installed on cars of

126. ## english

First you get to read something on the Internet or in your favorite magazine, and then write a summary of it. Choose any subject of interest to you personally (stamps, bees, security alarms, global warming, sports, etc.) and read about it (or listen to a

What time frame is Jiskha in? Like Mountain time?

128. ## geography

geography envoirment

129. ## science

two equally charged spheres, X and Y, repel each other with a force of 8.0 x 10^-6 N when placed a certain distance apart. Another identical, but uncharged, sphere is touched to sphere Y and then moved next to sphere X. Calculate the electric force acting

130. ## Chemistry

Can someone explain to me in simple terms what is relative mass and absolute mass? And how to calculate them too. Thanks.

131. ## Pyschology

Examples of how are critical thinking skills affected by long term memory?

132. ## accounting

For each of the following, indicate the accounting concept or constraint that has been violated, if any: 1) The company currently records its accounting transactions and prepares its financial reports manually. The cost of using a new computerized

133. ## history

What impact did the War of 1812 have on the American Federal Government? My answer is that it strengthened it with economic opportunities, diplomatic avenues, and nationalism. Is this correct?

134. ## Social Studies-URGENT

I'm doing a project for social studies, and I want to know if the African Queen Lily grows in Sudan. Please help!

135. ## chemistry

a solution is made by mixing 14.5g of NaOH and 72.0 mL of 0.250 M HNO3

136. ## PHYSICS

The peak value of the ac current in a circuit is 6.0 A, and peak value of the ac voltage applied to the circuit is 8.9 V. What is the average power P delivered to the circuit?

137. ## medical

whaen comparing the flow of lymph in the lymphatic system with the flow of blood in the circulatory system, it can be said that the lymphatic system also : A- USES A PUMP B- CONTAINS FLUID THAT TRAVELS IN ONLY ONE DIRECTION C-USES VALVES TO PREVENT

138. ## chemistry

A 375 g sample of well water is found to contain 17.0 mg of lead. How much lead (in parts per million) is in the well water? Round to the nearest tenth. Don't forget the unit.

139. ## Chemistry - NO2 Calculation

(a) Calculate [NO2] at each time interval, based on [O2]. Assume initial [NO2] = 0.0 mol/L. how do i calculate NO2 at this time intercal so when t= 600s O2 in mol/l = 0.0021

140. ## History

How did India experience that arrival of the west, in light of the past? How did India experience the western domination? How did India emerged out of western domination in the 20th century as an independent nation?

141. ## Physical science

What is the mass in kg of a cone made of brass that has a base radius of 25 cm and a height of 50 cm.

142. ## Physics

Tarzan tries to cross a river by swinging from one bank to the other on a vine that is 8.8 m long. His speed at the bottom of the swing is 7.2 m/s. Tarzan does not know that the vine has a breaking strength of 1.0 multiplied by 103 N. What is the largest

143. ## physics

Suppose a sound of frequency 1200 Hz is emitted from a speaker 15 meters away from you. At YOUR location, the intensity is 1.0E-7 W/m2. Let me assume your eardrum has area 8E-5 m2. If the sound continues for 20 seconds, what total amount of energy is

144. ## Physics

Two loudspeakers are 2.42 m apart. A person stands 3.42 m from one speaker and 2.82 m from the other. What is the lowest frequency at which destructive interference (sound cancellation) will occur at this point?

145. ## beginning/intermediate college algebra

true or false:the graph of the equation 3x-5y=10 goes through (0,-2)

146. ## PHYSICS

If the current is composed of Na+ ions (q = +e), how many such ions flow in 0.7 s?

148. ## Chemistry

An unknown gas has a molecular weight of 30.07 g/mol. What is the density of the gas at STP?

149. ## trig

using the given point (9, squareroot 19) find the value of cosx

150. ## science

tell me about elastic energy of dislocation

152. ## algebra

can someone help me to show how to solve -x+y=3

153. ## Physics

A mass of 0.38 kg is attached to a spring and is set into vibration with a period of 0.22 s. What is the spring constant of the spring?

154. ## Physics

A trapeze artist swings in simple harmonic motion with a period of 3.2 s. The acceleration of gravity is 9.81 m/s2 . Calculate the length of the cables supporting the trapeze. Answer in units of m.

155. ## chemistry

When 15.3g of NaNO3 was dissolved in water inside a constant pressure calorimeter, the temperature fell from 25.00 °C to 21.56 °C. If the heat capacity of the calorimeter (including the water it contains) is 1071 J/°C, What is the enthalpy change for

156. ## Calculus

Can two level curves of a function intersect; explain?

157. ## Physics-10

A vehicle that weighs 400N on the surface of the earth is traveling in outer space at a speed of 400m/s. it can be stopped by applying a constant force of 20N for?

158. ## math 092

can i get help with solving problems