Martin

Most popular questions and responses by Martin
1. Chemistry

How many mole of H2 will be produced if 0.500 grams of magnesium is reacted with 10.00mL of 2.0 M HCl? I've concluded the answer is 0.02 moles of H2, but I'm doubting myself a lot because I don't understand the aspects of the balanced chemical equation and

2. Physics

a) A 40 cm radius wheel is rotating at 20rad/sec. How fast is this wheel moving across the ground? b) How far (in meters) will this wheel move in 6 seconds?

3. Physics

a) Find the angular velocity of a 40 cm radius wheel that is moving at 20 m/s. b) How many times will this wheel rotate in 5 seconds?

4. Physics

A race car starts from rest in the pit area and accelerates at a uniform rate to a speed of 35 m/s in 11s, moving on a circular track of radius 500 m. Determine the tangential and centripetal components of the net force excreted on the car(by the ground)

5. Chem

given the balanced equation: 2Al2O3(s)-->4Al(s)+302(g) What is the total number of moles of O2 that are produced when 8.0 mol of Al2O3(s)are totally decomposed ? please help me.

6. Physics

a) Find the angular velocity of a wheel that rotates 6 times every 4 seconds. b) What is the tangential velocity of the outside of the wheel if the radius is 15 cm?

7. Algebra

The ratio of the areas of two squares is 32/63. After rationalizing the denominator, the ratio of their side lengths can be expressed in the simplified form (a*sqrt b)/c where a, b, and c are integers. What is the value of the sum a + b + c?

8. chemistry

URGENT!! You wish to prepare 1 L of a 0.02 M potassium iodate solution. You require that the final concentration be within 1% of 0.02 M and that the concentration must be known accurately to the fourth decimal place. How would you prepare this solution?

9. CHEM

How can I calculate a pH of hypochlorite buffer into LiCLO with only initial concentrations and no Ka value? [CLO-]=.1M [LiCLO]=.1M

10. Calculus

A leaky cylindrical oilcan has a diameter of 4 inches and a height of 6 inches. The can is full of oil and is leaking at the rate of 2 cubic inches/hr. The oil leaks into an empty conical cup with a diameter of 8 inches and a height of 8 inches. a. At what

11. History :)

Can someone help with this one please? Select one reform movement from the Progressive Era. Describe the movement and its impact on South Carolina. Provide details and examples that support how this movement changed South Carolina. Websites and examples

12. Chem

Solid urea, (NH2)2CO, burns to give CO2,N2, and liquid H2O. Its heat of combustion is -632.2 kJ/mol. Balance the equation for combustion of urea, and calculate the heat generated per mole of H2O formed. (Enter in kJ.)

13. History

Which is the best definition of naturalization? The process of living and working in the U.S. in order to become a citizen The act of taking an oath of loyalty to the U.S. in order to become a citizen The legal steps taken for a citizen born in another

14. MATH

Use a table of trigonometric values to find the angle è in the right triangle in the following problem. Round to the nearest degree, if necessary. cos è=? A=22 H=38

15. Calculus

A balloon rises vertically at a rate of 8 feet/sec. A bird flies 40 feet above ground toward the balloon’s path at 20 feet per second. At what rate is the distance between the bird and the balloon changing when the bird is 50 feet from the balloon

16. Science

A snooker ball X of mass 0.3kg moving at 5m/!@#\$%^& a stationary ball Y of mass 0.4kg and Y move at a velocity of 2m/s at angle to the initial direction of X. Find the velocity and direction of X after hitting

17. Physcial Science

Alpha particle tracks through gases and thin metal foils show few deflections. What does this tell us about the atom?

18. english

2. Tecumseh's "Let the white race perish" speech is A. a logical list of reasons why the whites should be resisted. B. a satire on the white race and its traditions. C. a plea to the people's reason. D. an appeal to the emotions of his listeners.

19. chemistry

Hvap 40.65 kJ/mol Hf -285.83 kJ/mol Hfusion 6.03 kJ/mol specific heat 4.186 J/gC molar mass 18.02 g How much energy is consumed by thawing 4.3 g ice?

20. Physics 1

(I) determine the tangential and centripetal components of the net force excreted on the car(by the ground) when it accelerates at a uniform speed of 15 m/s in 11 s, moving on a circular track of radius 500m. The cars mass is 1100kg.

21. Physics

A student applies an upward force of 58 N to a 5.1-kg physics textbook. Find the book’s acceleration (positive for up, negative for down).

22. Physics

A body vibrates in simple harmonic motion with an amplitude of 5 cm and a frequency of 0.50 Hz. a) Calculate: i) the maximum acceleration ii) the maximum velocity iii) the magnitude of the acceleration and velocity when the body is displaced 10 mm from its

23. Basic Statistics

In each of the following situations state whether or not the given assignment of probabilities to individual outcomes is legitimate, that is, satisfies the rules of probability. If not, give a reason a) roll a die and record the count of spots on the

24. Physics

The piston in a particular car engine moves in approximately simple harmonic motion with an amplitude of 8 cm. The mass of the piston is 8 kg and the piston makes 100 oscillations per second. Calculate: a) the maximum value if the acceleration of the

25. physics 30

A flash of lightning transfers 1.5 x 10^9 Joules of energy through a potential difference of 5.0 x 10^7 Volts between a cloud and the ground. Calculate the quantity of charge transferred in the lightning bolt. How many electrons were transferred? Does this

26. comper science

write a program that accept the name of a student score obtained in 5 courses and compute the average score of the student.your program must display the name of that student on tab 5

27. pre-algebra

your family is driving to houston,texas.A sign indicates that you are 700 miles from houston.Your car's trip odometer indicates you are 400 miles from home.YOu are traveling at an average speed of 60 miles per hour. A. write an expression for the

28. biology

Suppose you have monohybrid snapdragons in your garden and you find that they produce red seeds to white seeds in the ratio of 3:1. If the alleles are designated R (red seeds) and r (white seeds), what are the probable phenotypes of the parents (P1)? a all

29. math

your family is driving to houston,texas.A sign indicates that you are 700 miles from houston.Your car's trip odometer indicates you are 400 miles from home.YOu are traveling at an average speed of 60 miles per hour. A. write an expression for the

30. Physics 1

(I) determine the tangential and centripetal components of the net force excreted on the car(by the ground) when it accelerates at a uniform speed of 15 m/s in 11 s, moving on a circular track of radius 500m. The cars mass is 1100kg.

31. math

solve the system 7x^2 - 5y^2 + 20y = 3 21x^2 + 5y^2 =209

32. science

A step-up transformer has 120 turns on its primary coil. It has 1150 turns on its secondary coil. The primary circuit is supplied with an alternating current at 120 V. The current in the secondary circuit is 2.4 A. What current is in the primary circuit?

33. History

Which set of issues led to the Civil War? Economics, religion, boundaries Politics, education, voting rights ** Slavery, politics, economics Voting rights, slavery, politics

34. physics

Consider a system of N identical particles. Each particle has two energy levels: a ground state with energy 0, and an upper level with energy . The upper level is four-fold degenerate (i.e., there are four excited states with the same energy ). (a) Write

35. Chemistry

Consider the voltaic cell: Zn(s) / Zn2+(aq) // H+(aq) / H2(g) / Pt(s) Calculate the value of Ecell, in V, when [Zn2+] =1.00 M and [H+] = 0.00100 M DATA: Zn2+(aq) +2 e¯ ---> Zn(s);Eo = - 0.76 V 2 H+(aq) + 2 e¯ ---> H2(g);Eo = 0.00 V

36. math word problem

Case Eastern Junior College awarded 26 varsity letters in crew, 15 in swimming, and 16 in scoccer. If awards went to 46 students and only 2 lettered in all sports, how many students lettered in two of the three sports?

37. statistics

4. The Graduate Record Exam (GRE) has a combined verbal and quantitative mean of 1000 and a standard deviation of 200. Scores range from 200 to 1600 and are approximately normally distributed. For each of the following problems: (a) draw a rough sketch,

38. AP Chemistry

If 15.0mL of 2.50M NaCl is mixed with 60.0mL of 0.300M Pb(NO3)2, what is the mass of the precipitate

39. Physics 30

A test charge of 5.0x10^-6 C is moved 2.0 cm through an electric force of 6.0 x 10^-7 N . What is the change in evergy of the test charge? What is the change in voltage on the charge? Help

40. economics

suppose the marginal propensity to consume is 0,6 and investment spending increases by 20 billion. by how much will total production or income change?

41. modern physics

a hunter on the ground fires a bullet in the northeast direction which strikes a deer 0.25 metre away from him, the bullet travel with a speed of 1800m/hr.at the instant an airplane is directly over the hunter at an altitude of one metre and is traveling

42. Political Science

In Marbury v. Madison, the Supreme Court established the principle of constitutional review by? I am seconding guessing myself on my answer so can you point me the right direction is it: claiming that Section 13 of the 1789 Judiciary Act providing that the

43. calculus 1

find the total area between the curve ( y= 4-x to the second power) and the x-axis over the interval [-3,7]

44. Chemistry

Calculate the rate at which N2O4 is formed in the following reaction at the moment in time when NO2 is being consumed at a rate of 0.0521 M/s. 2NO2(g) N2O4 (g) I am not really sure how to go about this problem. rate = k (N2O4) d(NO2)/dt = -2 d(N2O4)/dt

45. Biology

Hi there, Describe the role of bacteria in biotechnology and genetic engineering. I'd appreciate the help. Thanks. Since this is not my area of expertise, I searched Google under the key words "bacteria biotechnology" to get these possible sources:

46. Maths

A father was three times as old as his son fifteen years ago and four times his sons age nineteen years ago. When was the father twice as old as the son?

47. algebra A055,

World Records in the 1500-m Run. The formula R = -0.075t + 3.85 can be used to predict the world record in the 1500-m run t years after 1930. Determine (in terms of an inequality) those years for which the world record will be less than 3.5 min. { Y l Y >

48. algebra

World Records in the 1500-m Run. The formula R = -0.075t + 3.85 can be used to predict the world record in the 1500-m run t years after 1930. Determine (in terms of an inequality) those years for which the world record will be less than 3.5 min.

49. physics

A 2.40 kg firecracker explodes into two pieces and produces 170 J of heat, light, and sound energy. One of the pieces has a mass of 0.800 kg and a speed of 4.50 m/s after the explosion. If the mass of the other piece is 1.20 kg, what is its speed after the

50. math

If you borrow \$15,000 from your dad for college and you agree to pay him \$25,000 back at 8% compound interest per year. How many years do you think you have to do this? In other words, given the amounts and the interest rate, what is the number of years?

51. Math

A scale drawing of an office building is not labeled but indicates 1 / 3 inch = 4 feet. On the drawing one wall measures 4 and 2 / 3 inches. How long is the wall?

52. Chemistry

A reaction proceeds according to the following mechanism: Cl2 ⇌ 2 Cl (fast equilibrium) Cl + H2 ⇌ H2Cl (fast equilibrium) H2Cl + Cl → 2 HCl (slow) What is the rate law for this reaction?

53. calculus 1

find the total area between the curves ( y= 4-x ^2 ) and the x-axis over the intervals [0,4]

54. algebra A055,

World Records in the 1500-m Run. The formula R = -0.075t + 3.85 can be used to predict the world record in the 1500-m run t years after 1930. Determine (in terms of an inequality) those years for which the world record will be less than 3.5 min. { Y l Y >

55. Political Science

In Gibbons v. Ogden, the Supreme Court held that? In Chapter 7 Federal Authority and the Limits to State Authority. If I am understanding right that the 10th Amendment trumps the Interstate Commerce Clause. I am I right?

56. chemistry

Hvap 40.65 kJ/mol Hf -285.83 kJ/mol Hfusion 6.03 kJ/mol specific heat 4.186 J/gC molar mass 18.02 g How much energy is consumed by thawing 4.3 g ice?

57. Chemistry

A rock contains 200. µmol 238U (t1/2 = 4.5 109 yr) and 116 µmol 206Pb. Assuming that all the 206Pb comes from decay of the 238U, estimate the rock's age. Please explain step by step.

58. Discrete Math

You have two decks of 26 cards. Each card in each of the two decks has a different letter of the alphabet on it. You pick at random one card from each of the two decks. A vowel is worth 3 points and a consonant is worth 0 points. Let X = the sum of the

59. physics

1.A proton enters a 2.0 X 10^-2 T magnetic field with a speed of 5.8 X 10^4 m/s. What is the radius of the circular path it follows? formula?? 2.Electrons moving at 3.5 X 10^4 m/s pass through an electric field with an intensity of 5.6 X 10^3 N/C. How

60. Physics

A driver jumps off the 3.0m diving board with an initial velocity of 5.0m/s. (a) Determine the maximum height, (b) The time to reach the maximum height, (c) The time it took to touch the water, and (c) The speed when touching the water.

61. Political Science

In Gibbons v. Ogden, the Supreme Court held that?

62. phsics

a man weighs 1370N on earth what would he weigh on jupiter where free fall acceleration is 25.9 m/s2 the acceleration of gravity is 9.8 m/s2 in units of N

63. COMM100

Which of the following would be an appropriate way to use the DECIDE tool in response to research suggesting that there are differences between the way men and women communicate?

64. physics

Given that the mass of an electron is 9.1 x 10^-28 grams and the charge on an electron is 1.6 x 10^-19 Coulombs, calculate the voltage required to lift an electron 5 cm. not quite sure how to do this.

65. arithmetic

The nth term of the sequence 4,11,18,...is167 find n

66. phycis

A roller coaster has two hills and starts from rest atop the first hill , which is the higher of the two hills . The secound hill increases if the height of the initial hill is increased by 20m

67. Math

Suppose R is the relation on N where aRb means that a ends in the same digit in which b ends. Determine whether R is an equivalence relation on N. And, Suppose that R and S are equivalence relations on a set A. Prove that the R ¿ S is also an

68. physics

A ball moving with a speed of 26 m/s strikes an identical ball that is initially at rest. After the collision, the incoming ball has been deviated by angle 1 = 50° from its original direction, and the struck ball moves off at angle 2 = 29° from the

69. Math

Write an integer that is represented by the bold words in the following sentence. The temperature dropped 17 degrees between noon and midnight.

70. Discrete Math

How many ways can you get a bunch of 4 books to give a friend if you have 30 books (15 novels, 10 history book and 5 math books)?

71. chemistry

NaOH + CH3COOH = CH3COONa + H2O calculate the mass concentration in gdm-3 of the orinigal viniger

72. Mat 116 Algebra 1A

7[3m-(m+2)]>-6(m+3) Use set-builder notation to describe the complete solution {m|m > ? } (type an equality symbol; then type an integer or a simplified fraction.)

73. math

The atomic number of cadium is half the atomic number of curium. Define a variable and write an expression for the atomic number of cadmium. I'm working in a group with my friends and we need help we're not the same people.

74. physics

If ball c slid down the hill without friction, how fast would it be traveling the instant it reached the bottom of the hill?

75. Statistics

How do you code your data?

76. World History

How are the Assyrian and Phoenician empires alike?

77. science

what is the life cycle of moss

78. Is this a correct english sentence?

My father had two sons, from whom I was the oldest, and two daughters. Sorry for the inconveinience, but I'm not English, and I've got some translation to do

79. english literature

i am writing a research paper about JOHN KEATS and his 3 works ( social political religious or any)_ but i didn't find some of the things about him. my question is: WHAT ARE THE SOCIAL POLITICAL AND RELIGIOUS CONTRIBUTION OF JOHN KEATS TO THE ENGLISH

80. integrated science

what is.. the modem system of units used by scientists? what is.. the curved surface of a liquid? what is.. a process used to find the volume of an irregularly shaped object? (1) S. I. (International scientific) (2) meniscus (3) total immersion (liquid

81. Maths

Solve Simultaneous Equetion Using Elimination Method: (A)2x - 3y= -3 and 3x - 7y= -1.

82. Chem

A student mixed 6 g of ice at -3.4 degrees celsius with 1 g of steam at 103 degrees celsius. What was the final temperature of this mixture.i tried equalling mcdelta T. Please help asap. I would be eternally grateful

83. functions

What is the rule for input 0 output -1

84. Math

An investment was worth \$1000. By the end of 2010 the investment had lost 30%. What percent must the investment grow by in 2011 to be worth \$1000 by the end of 2011? Round your answer to the nearest tenth of a percent.

85. English paper 3

An discursive essay of this topic , both parrents should assume equal responsibility in raising a child,agree or dis agree

86. Sciience

Given: angle A is 20˚, b = 50 cm, for what possible range of lengths of side “a” would triangle ABC have two possible solutions (approximate to 2 decimal places)?

88. Percentage

The usual price of a suitcase was \$100. During a sale, a 13% discount was given. Mr Lee bought the suitcase but had to pay 7% GST on the selling price. a.) What was the selling price of the suitcase? b.) How much did Mr Lee pay for the suitcase?

89. physics

given that the mass of an electron is 9.1 x 10^-28 grams and the charge on an electron is 1.6 x 10^-19 Coulombs, calculate the voltage required to lift an electron 5 cm. the question was previously answered, but I did'nt understand it .. could some show me

90. science

how does the moon move through space ?

91. mechanics

Two 20kg weights are hung from light strings that pass over frictionless pulleys. The ends of the strings are connected to a small, light spring balance, S, calibrated in kg. The pulley axes are mounted on the wall of a lift in a 50-storey building. What

92. Arithmetic

Given the sequence Tq=-7+3(q+4) find T4,and x if Tx=50.

93. physics

A ball moving with a speed of 26 m/s strikes an identical ball that is initially at rest. After the collision, the incoming ball has been deviated by 1 = 50° from its original direction, and the struck ball moves off at 2 = 29° from the original

94. biology

A gene for flower color can have multiple alleles like purple, white, or red. true or false?

95. teacher aide

how children learn

96. Statistics

What is the Central Limit Theorem and how can it be used in statistics?

97. Statistics

I have to sample 300 persons. How do I go about doing this and how do I know that the population I have chosen has the characteristics that I am looking for?

98. Macroeconomics

Which of the following aren't included in the measurement of GDP? Exports Personal income Consumption spending Government spending on goods and services Transfer payments Net interest Imports Investment spending

99. math

a pasta machine costs \$33.The ingredients to make one batch of pasta cost \$.33.The same amouunt of pasta puchased at a store costs \$.99.How many batches of pasta will you have to make for the cost of the machine and ingrediants to eequal the cost of buying