# mathew

Popular questions and responses by mathew
1. ## chemistry

oxidation state of nitrogen in n2h4

2. ## math

Disks of radius 4 cm are cut from a rectangular plastic sheet of length 84 cm and width 24 cm. How many complete disks can be cut out? Find (a) the total area of the discs out (b) the area of sheet wasted I did it but the answers on the back of the book do

3. ## math

If you eat 2/3 of a pizza, and are left with 12 slices, how many slices are in 1/2 of the pizza?

4. ## physics

Two ice skaters stand facing each other at rest on a frozen pond. They push off against one another and the 48-kg skater acquires a speed of 0.65 m/s. If the other skater acquires a speed of 0.84 m/s, what is her mass?

5. ## math

Mrs. Herby bought some carrots. She put 2/5 of them on a platter and the rest in a plastic bag. If there were 8 carrots on the platter, how many carrots were there in the plastic bag?

6. ## physics

A 66-kg baseball player slides into third base. He starts his slide at a speed of 4.3 m/s and his speed is zero just as he reaches the base. If the coefficient of friction between his clothes and the surface of the baseball infield is 0.60, determine the

7. ## chemistry

1) Aqueous solutions of potassium sulfate and ammonium nitrate are mixed together. Which statement is correct? A) Both KNO3 and NH4SO4 precipitate from solution B) A gas is released C) NH4SO4 will precipitate from solution D) KNO3 will precipitate from

8. ## chemistry

use exponential notation to express the number 480 in 3 significant figures and 4 significant figures

9. ## math

0.7 of which is 3.43

10. ## physics

Which of the following statements about electric field lines due to static charges are true? (Select all that apply.) Electric field lines can never cross each other. Static charges can create closed loop electric field lines that do not begin or end on a

11. ## chemistry

A student weighs out 0.568 g of KHP (molar mass = 204 g/mol) and titrates to the equivalence point with 36.78 mL of a stock NaOH solution. What is the concentration of the stock NaOH solution? KHP is an acid with one acidic proton. a. 3.15 M b. 0.0757 M c.

12. ## physics

A 0.450 kg hammer is moving horizontally at 6.00 m/s when it strikes a nail and comes to rest after driving it 1.00 cm into a board. (a) Calculate the duration of the impact. (b) What was the average force exerted on the nail?

13. ## Language Arts

1. What is the key to an effective search for information as you prepare for your presentation? (1 point) A. Prewriting B. Strong research skills C. Paraphrasing D. Drawing conclusions 2. Why would a website that is selling a service not be a credible

14. ## chemistry

Balance following oxidation reduction reactions using oxidation states method? a) Cl2(g) + Al(s) --> Al3+(aq) + Cl- b.) O2(g) + H2O(l) + Pb(s) --> Pb(OH)2(s) c) H+(aq) + MnO4-(aq) + Fe2+(aq) --> Mn2+(aq) + Fe3+(aq) + H2O(l)

15. ## math

4/100 of which is 0.8

16. ## chemistry

An unknown diprotic acid requires 26.66 mL of 0.117 M NaOH to completely neutralize a 0.845 g sample. what is the molar mass of the acid?

17. ## physics

Two charges q 1 = −3.20 nC and q2 = +8.96 nC are at a distance of 1.94 µm from each other. q 1 is fixed at its location while q 2 is released from rest. (a) What is the kinetic energy of the charge q 2 when it is 0.340 µm from q 1? J (b) The charge q 2

18. ## chemistry

A 100 L flask contains a mixture of methane and argon gasses at 25 degree C . The mass of argon present is 228 g and the mole fraction of methane in the mixture is 0.650 . calculate the total kinetic energy of gaseous mixture

19. ## chemistry

A 18.3 g piece of aluminum (which has a molar heat capacity of 24.03 J/oC mol) is heated to 82.4oC and dropped into a calorimeter containing water (specific heat capacity of water is 4.18 J/goC) initially at 22.3oC. The final temperature of the water is

20. ## physics

One hazard of space travel is debris left by previous missions. There are several thousand masses large enough to detect by radar orbiting the earth, but there are far greater numbers of very small masses such as flakes of paint. Calculate the force

21. ## chemistry

30 ml of sample of unknown strong base is neutralized after the addition of 12 ml of a 0.150 M HNO3 solution if the unknown base concentration 0.0300 M give the possible identities for the unknown base

22. ## chemistry

At 500 K in the presence of a copper surface, ethanol decomposesaccording to the following equation. C2H5OH(g) CH3CHO(g) + H2(g) The pressure of C2H5OH was measured as afunction of time and the following data were obtained. Time (s) PC2H5OH(torr) 0 250.

23. ## physics

Calculate the acceleration of a sled that is heading down a 50° slope (one that makes an angle of 50° with the horizontal). The coefficient of kinetic friction on ice is μk = 0.100. (Take the x direction to be parallel to and down the slope and the y

24. ## ap chemistry

what mass of barium sulfate can be produced when 100 ml 0.100 M of solution of barium chloride is mixed with 100.0 ml of a 0.100 M solution of Iron (III) sulfate

25. ## Calculus

Consider the curve given by y^2 = 2+xy (a) show that dy/dx= y/(2y-x) (b) Find all points (x,y) on the curve where the line tangent to the curve has slope 1/2. (c) Show that there are now points (x,y) on the curve where the line tangent to the curve is

26. ## :)

Which white person discussed or mentioned in Narrative Life is most important?

27. ## Science

A car is travelling along a straight road. The driver suddenly observes that the road ahead is flooded and applies the brakes. Describe what happens to the car and the brakes. Your answer should include details of braking distance and braking force.

28. ## Maths

A windscreen wiper of a vehicle clears out an angle at 108 degree.what is the area

29. ## physics

What is the magnitude and direction of an electric field that exerts a 4.00 ✕ 10 -5 N upward force on a - 1.80 µC charge? N/C

30. ## chemistry

An analytical procedure requires a solution of chloride ions ,How many grams of CaCl2 must be disolved to make2.15L of 0.0520 M C

31. ## chemistry

n the spectroscopic analysis of many substances, a series of standard solutions of known concentration are measured to generate a calibration curve. How would you prepare standard solutions containing 10.0, 25.0, 50.0, 75.0, and 100. ppm of copper from a

32. ## physics

When a hammer strikes a nail, it is compressed along its length. Suppose that a steel nail 10.00 cm long and 3.00 mm in diameter is compressed an average of 65.0 µm by a 0.460 kg hammer during a 1.20 ms collision. (a) What average force was exerted on the

33. ## Physics

A young woman named Kathy Kool buys a sports car that can accelerate at the rate of 4.77 m/s2. She decides to test the car by dragging with another speedster, Stan Speedy. Both start from rest, but experienced Stan leaves the starting line 1.04 s before

34. ## Science

In rabbits, B represents the allele for black coat and b represents the allele for white coat. Black is dominant over white. If a rabbit has the genotype Bb, what is the rabbit's phenotype? A) gray B) black C) white D) BB X bb d?

35. ## Science

In the chart, the organism Rr represents a genetically _____________ individual. A) heterozygous B) homogeneous C) homozygous D) retrozygous a or c?

36. ## math

A golfer hits a ball. The ball leaves the club with an initial upward velocity of 40 meters per second. If the ball is 0.25 meters off the ground when it leaves the golf club, about how many seconds will it take for the ball to hit the ground?

37. ## LANGUAGE ARTS HELLPPPP!!!!!

1. What is the key to an effective search for your information as you prepare for your presentation? (1 point) A. prewriting B. strong research skills C. paraphrasing D. drawing conclusions

38. ## science

What will happen when titanium reacts with oxygen?

39. ## physics

The curves on a race track are banked to make it easier for cars to go around the curves at high speed. Draw a free-body diagram of a car on a banked curve. From the motion diagram, find the direction of the acceleration. The acceleration is directed

40. ## physics

On the moon, the acceleration due to gravity is only 1.6 m/s/s. If someone on earth can throw a baseball 24.2 m high, how high could he throw it on the moon?

41. ## chemistry

The reaction SO2 + H2O =H2SO4 Is the last step in the commercial production of sulfuric acid . the enthalpy change for this reaction is -227 KJ . In designing a sulfuric acid plant is it necessary to provide for heating or cooling of the reaction mixture ?

42. ## physics

Displacement vectors A, B, and C add up to a total of zero. Vector A has a magnitude of 1550 m and a direction of 22.9° north of east. Vector B has a direction of 41.0° east of south, and vector C has a direction of 35.2° north of west. Find the

43. ## chemistry

A 30 ml sample of unknown strong base is neutralized after the addition of 12 ml of a 0.150 M HNO3 solution if the unknown base concentration is 0.0300 M give some possible identities for the unknown base

44. ## physics

A man holding a rock sits on a sled that is sliding across a frozen lake (negligible friction) with a speed of 0.540 m/s. The total mass of the sled, man, and rock is 93.5 kg. The mass of the rock is 0.300 kg and the man can throw it with a speed of 15.0

45. ## ap chemistry

what volume 0,100M of Na2PO4 is required to precipatate all the lead(II) ions from 150 ml of 0.250M Pb(NO3)2

46. ## Physics

A car drives up a straight hill at a constant speed of 60 kilometers per hour. A truck drives over the crest of the hill at a constant speed of 60 miles per hour. What is the net force on the car and on the truck? 1. both not zero 2. not zero; zero 3. both

47. ## Physics

An object traveling at a constant 20 m/sec in a circular path is changing its 1. velocity. 2. speed. 3. weight. 4. mass.

48. ## statistics

6. A geography student needs to take three 300- level and three 400- level geography classes next semester in order to graduate. If there are 10 300- level courses being offered and 7 400- level courses being offered, how many different schedules could the

49. ## algebra2/trignometry

in right triangle PQR,Q=90DEGREE,PQ=4 AND PR=7 WHAT IS ANGLE R TO THE NEARST TENTH OF A DEGREE

50. ## Lines and Slopes Math

A line is perpendicular to x+3y-4=0 and has the same y-intercept as 2x+5y-20=0. Find an equation for the line

51. ## Math

A line is parallel to 5x+2y-8=0 and has the same y-intercept as x+4y-12=0 Find an equation for the line.

52. ## Algebra

almost done with Algebra...help! 2 3x – 6(2x – 0.055) = 10x + 0.515 I don't know what want but assuming your solving for x... 23x-12x-.33= 10x + 0.515 11x-.33= 10x + 0.515 x= 0.845 You need to clarify your post. Is that 23x or 3x (for problem #2

53. ## Math

Kristin worked a total of 10 1/2 hours over 2 days. She worked 6 3/4 hours the first day and h hours the second day. Which equation represents how to find the number of hours Kristin worked the second day? A. 6 3/4h=10 1/2 B. h-6 3/4=10 1/2 C.10 1/2h= 6

54. ## math

if one of the zeroes of a cubic polynomial x^3+ax^2+bx+c is -1.find the product of other 2 zeroes

55. ## Algebra 2

If the slope turns out to be 4/0 in an equation them is it undefined. Also, therefore, would the y intercept not be able to be determined or can it be determined?

56. ## Math

1. The variables x and y vary directly. When x is 3, y is 6. Find x when y = 2/3. 2. The force acting on an object varies directly with its acceleration. A force of 25 newtons accelerates an object at 1.25 m/s. What is the acceleration of a 35 newton

57. ## Algebra

A physics student stands at the top of a hill that has an elevation of 37 meters. He throws a rock and it goes up into the air and then falls back past him and lands on the ground below. The path of the rock can be modeled by the equation y = -0.02x^2 +

58. ## math

write each fraction as a decimal and each decimal as a fraction in simplest form. 1.8/20 2.0.64 3.3/100

59. ## Physics

A small child is learning to ride a bike for the first time. Her dad decides it would be a good idea to start her on a small hill. The hill is inclined at 3.30° to the horizontal. The child starts partway down the hill, 9.00 m away from her dad, who stays

60. ## Physics

A 70 cm diameter wheel is rotating at 1 300 revolutions per minute and a small 5g mass is fixed to the outer edge of the wheel. Calculate the strength and direction of the centripetal force that is exerted on the mass.

61. ## Chemistry

NaN3--->Na+N2 How many moles of Na are produced if 3.5 moles NaN3 react?

62. ## math

How many fewer minutes would it take the driver to travel a distance of 10 miles at a speed of 65 miles per hour than at a speed of 50 miles per hour? Round your answer to the nearest minute.

63. ## english

Which of the following sentences correctly follows the rules of capitalization? a. The President of the company made a speech today b. I would love to spend my summers in the North c. He met with senator John Brown from Kansas d. My Grandfather told me

64. ## Algebra

John drove 5 hours before stopping to get gas. After he filled the tank, he increased his speed by 10 MPH. If he completed a 490-mile trip in 9 hours of driving time, how fast did he drive before he stopped for gas?

65. ## Chimistry

A piece of metal (75 g at 98.0°C) was dropped in water (95 g at 22.0°C) and the final temperature was measured to be 31.2°C. If the specific heat of water is 4.18 J/g°C. What is the heat capacity of the metal?

66. ## physics

(a) Find the electric potential difference V B − V A due to a point charge q 1 = −2.65 nC that is 0.250 m from location A and 0.410 m from location B. V (b) A charge q 2 moving from B to A gains in kinetic energy. What is the sign of this charge?

67. ## biology

I have to write an essay on about why organ donation should be mandatory in Canada. I need help thinking of arguments. Some that I have thought of are: 1. there is a shortage of organs for transplants 2. it improves the life of the recipient 3. After death

68. ## physics

A proton is acted on by an uniform electric field of magnitude 233 N/C pointing in the positive x direction. The particle is initially at rest. (a) In what direction will the charge move? (b) Determine the work done by the electric field when the particle

69. ## physics

(a) A charged particle accelerates as it moves from location A to location B. If V A = 170 V and V B = 210 V, what is the sign of the charged particle? positive negative (b) A proton gains electric potential energy as it moves from point 1 to point 2.

70. ## physics

Two parallel conducting plates are separated by 10.0 cm, and one of them is taken to be at zero volts. (a) What is the electric field strength between them, if the potential 8.50 cm from the zero volt plate (and 1.50 cm from the other) is 450 V? kV/m (b)

71. ## physics

An electron has an initial velocity of 2.00 ✕ 10 6 m/s in a uniform 6.00 ✕ 10 5 N/C strength electric field. The field accelerates the electron in the direction opposite to its initial velocity. (a) What is the direction of the electric field? (b) How

72. ## chemistry

a) calculate the concentration of your unknown (Gatorade) using correct units Note if you did not run the Gatorade use absorbance =0.205 abs units in order to calculate the concentration of the dye in the Gatorade b) calculate of % T for an absorbance of

73. ## physics

A solid, uniform disk of radius 0.250 m and mass 60.4 kg rolls down a ramp of length 4.60 m that makes an angle of 18.0° with the horizontal. The disk starts from rest from the top of the ramp. (a) Find the speed of the disk's center of mass when it

74. ## physics

What is the force on the charge located at x = +8.00 cm in Figure 17.40(a) given that q = 5.00 n C and a = 7.00? (The positive direction is to the right.) N

75. ## physics

Guy has to get a piano onto a 2.4 m high platform. He can use a 3.0 m long frictionless ramp or a 4.0 m long frictionless ramp. Which ramp will Guy use if he wants to do the least amount of work? Either ramp as the work done is same in both cases. The

76. ## physics

A baseball (m = 145 g) traveling 20 m/s moves a fielder's glove backward 25 cm when the ball is caught. What was the average force exerted by the ball on the glove? Magnitude N Direction in the direction opposite to the ball's motion in the direction of

77. ## physics

How much work must be done to stop a 1070 kg car traveling at 111 km/h?

78. ## physics

Can the gravitational potential energy of a baseball ever be negative? Yes No Explain without using a formula.

79. ## physics

(e) If the speed of the ball at the bottom of the circle is v, what is the expression for the centripetal force on the ball in terms of its speed v and the length L of the string? Take the upward direction as positive and the downward direction as negative

80. ## physics

A football is kicked from the ground with a speed of 23m/s at an angle of 42 degrees above the horizontal a) how long is the football in the air b) how far does it travel

81. ## physics

A quarterback threw a football at 27 m/s at a certain angle above the horizontal. If it took the ball 3.3 s to reach the top of its path, how long was it in the air? s

82. ## physics

A cargo plane is moving with a horizontal velocity of vx = +230 m/s at a height of y = 840 m above level ground as shown in the figure below when it releases a package. Ignoring air resistance, how much time will it take the package to reach the ground?

83. ## math

They are five apple slices in each school lunch. If 35 students buy a school lunch, !@#\$%^& many apple slices are there ? Write an equation for this problem.

84. ## physics

Calculate the maximum deceleration of a car that is heading down a 14.5° slope (one that makes an angle of 14.5° with the horizontal) under the following road conditions. You may assume that the weight of the car is evenly distributed on all four tires

85. ## physics

A skydiver weighing 840 N opens his parachute at the appropriate height from the ground. The air exerts a significant upward drag force, which is initially greater than the weight of the diver. This helps to slow the skydiver down. What is the diver's

86. ## physics

A 75 kg person escapes from the burning building by jumping from the window 25 m above a catching net air resistance exerts a 95 N force on the person during the fall apply Newton second law find the acceleration during the fall find the velocity and free

87. ## physics

A mover has to move a heavy sofa of mass 66 kg to the second floor of the house. As he pulls on the rope tied to the sofa he makes sure that the rope is parallel to the surface of the ramp, which is at 30.0° to the horizontal. If the coefficient of

88. ## physics

The stone was thrown through a distance of 80 cm the act of throwing takes approximately 0.064 s. determine the launch velocity of the stone

89. ## physics

A contestant in a winter games event pushes a 41.0 kg block of ice in the positive direction across a frozen lake as shown in the Figure (a). The coefficient of static friction is 0.1 and the coefficient of kinetic friction is 0.03.

90. ## chemistry

Sodium vapor lamps are used in Chicago to light city streets. The light emitted (given off) by these lamps has a λ of 5.9 x 10-7 m. What is the λ in cm? What is the λ in nanometers (nm) [1 meter = 1 x 109 nm]? What is the ν of this radiation? In what

91. ## PROBATION AND PAROLE

According to psychoanalytic theory, the unconscious: A. consists of thoughts and feelings that can easily be called into consciousness. B. is capable of strongly influencing conscious behavior. C. is considered by Freudian thought to develop during

92. ## physics

An express subway train passes through an underground station. It enters at t = 0 with an initial velocity of 23.5 m/s and decelerates at a rate of 0.150 m/s2 as it goes through. The station in 215 m long. (a) How long is the nose of the train in the

93. ## physics

A jet needs to reach a takeoff speed of 75.0 m/s. If the runway is 1625 meters long, what minimum acceleration is needed? How much time will it take to reach the takeoff speed

94. ## physics

while cruising along dark stretch of highway at a speed of 25 m/s you see that bridge ahead has been washed out. you apply the breaks to and come to a stop in 4.0 sec construct the position vs time graph and acceleration vs time graph and motion graph for

95. ## physics

Displacement vectors A, B, and C add up to a total of zero. Vector A has a magnitude of 1550 m and a direction of 22.9° north of east. Vector B has a direction of 41.0° east of south, and vector C has a direction of 35.2° north of west. Find the

96. ## chemistry

A compressed gas cylinder contains 1.00 into 1000 g argon gas . the pressure inside the cylinder is 2050 psi at a temp of 18 degree . how much gas remains in the cylinder if the pressure is decreased to 650 psi at a temperature of 26 degree of 26 degree c

97. ## chemistry

A bicycle tire fitted was fitted with the air pressure of 75 psi at temperature 19 degree C riding the bike on a asphalt on a hot day increases temperature of the tire to 58 degree C. The volume increase by 4% . What is the new pressure

98. ## College Algebra (Word Problem)

A rectangular eld is to be fenced o along the bank of a river; no fence is required along the bank of the river. The material for the fence costs 8 dollars per running foot for the two ends and 16 dollars per running foot for the side parallel to the

99. ## chemistry

A beaker contain 300.ml of a 0,20 M Pb(NO3) solution. If 200 ml of 0,20M solution og MgCl2 is added to the beaker, What will be the concentration of Pb2+ ions in the resulting solution