# omar

Most popular questions and responses by omar
1. ## physics

a car, moving at 100 mi/hr, passes a stationary police car whose siren has a frequency of 500 Hz. what is the frequency change heard by observer in the moving car as he passes the police car? the velocity of sound in air is 343 m/s. ( 1 mi= 1.609 km).

2. ## physics 1

) An oil tanker’s engines have broken down, and the wind is blowing the tanker straight toward a reef at a constant speed of 1.5 m/s (Fig.1). When the tanker is 500 m from the reef, the wind dies down just as the engineer gets the engines going again.

3. ## chemistry

Consider the first order reaction A --> products where 25% of A disappears in 24 seconds. What is the half life of this reaction? ...i thought it would just be doubled but it isn't. i'd appreciate an explanation.

4. ## Physics

Two workers are sliding 310kg crate across the floor. One worker pushes forward on the crate with a force of 440N while the other pulls in the same direction with a force of 230N using a rope connected to the crate. Both forces are horizontal, and the

5. ## Physics

You pick up a 2.5kg can of paint from the ground and lift it to a height of 1.7m .How much work do you do on the can of paint? You hold the can stationary for half a minute, waiting for a friend on a ladder to take it. How much work do you do during this

6. ## physics

a 12 kg sled is pulled horizontally with a force of 82 N. the coefficent of the kentic friction of the sled is 0.42. draw a FBD of the sled.

7. ## accounting (balance sheet, retained earnings...)

Problem P3-5A On September 1, 2002, the account balances of Rijo Equipment Repair Corp. were as follows: Nbr: Debits Nbr: Credits 101 Cash \$4,880 154 Accumulated depreciation \$1,500 112 Accounts receivable 3,520 201 Accounts payable 3,400 126 Supplies

8. ## algebra

The ratio of the number of pencils to pens is 5 : 7. There are q pens. Express the number of pencils in terms of q.

9. ## math

36 students need to be divided into teams of equal size. How many different ways can the students be divided (assuming each team must have more than 1 member)?

10. ## OChem

A solution consisting of water and ethanol is found to have a refractive index of 1.3541 at 20 degrees C. The refractive indices at 20 degrees C of water and ethanol are 1.3330 and 1.3610, respectively. Determine the molar composition (in percent) of the

11. ## Physics

A chair of weight 85.0N lies atop a horizontal floor; the floor is not frictionless. You push on the chair with a force of F = 45.0N directed at an angle of 34.0∘ below the horizontal and the chair slides along the floor. Using Newton's laws, calculate

12. ## Chemistry

I did a lab for Organic Chemistry I did a simple distillation for an unknown and found that it boiled at 76 degrees. I also found out that the unknown was ethanol since we knew what the 4 possibilities were and mine was closest to ethanol. I also did a

13. ## chemistry

You want to prepare 500 ml of 1.0M acetic acid from a 17.4 M stock solution.What volume of stock solution is required?

12-3b

15. ## Math ASAP

Height: 10 inches Base Perimeter: 40 inches Lateral Surface Area: 400 square inches (^^^this is the total surface area of the sides) What is the Surface Area of the triangular prism? (the picture of the shape looks like a pentagon but the rectangle is much

16. ## Physics

density of ice 917 kg/m^3, density of sea water is 1025 kg/m^3, a piece of ice floating has a volume of 5.2 m^3, what is the weight of the heaviest bear the ice can support without sinking?

17. ## chemisrty

how many grams of cai2 are present in 3.28 moles? Can someone explaine how to do this question as well?

18. ## Math

A bottle of juice holds 3/8 gallon when it is full. If 1/3 of the juice has been poured out, how much juice is left in the bottle?

19. ## physics

object A exerts a gravitational force of magnitude 8.2 x 10^-10 N on object B. determine the magnitude of the gravitational force if, simultaneously, the separation distance is tripled, mA increased by 4 times and m8 is halved. explain your reasons and

20. ## chemistry

90Sr is one of the harmful radionuclides resulting from nuclear fission explosions. It decays by a first-order process with a half-life of 28 years. How many years would it take for 99.99% of a given sample released in the atmosphere to disintegrate?

21. ## physics

a 1500 kg car travelling at 16.7 m/s to the south collides with a 6300 kg truck that is initially at rest at a stop light. the car and the truck sticks togetherand moves together after the collision. what is the final velocity of the two-vehicle mass?

22. ## algebra

simplifying exspreesions

23. ## stoichiometry

What mass of solid aluminum hydroxide can be produced when 50.0 mL of 0.200 M aluminum nitrate is added to 200.0 mL of 0.100M potassium hydroxide?

I need to find 3 business in my comunity: one that is formed as a sole proprietory, one that is formed as a general partnership, and one that is formed as a corportion. Identify the business and explain what characteristic of the business form led the

25. ## java programming

the learner is asked to write a program using java with user input that caculate and displays, the number of months it will take the user to save an amount of money. the user must enter the

26. ## Math

Admission cost to a theatre are adults \$5,children \$2. If 1000 people paid to enter the theatre and the total receipts were \$3800. How many adults attended ?

27. ## Burnhamthrop Chemistry

initially 0.25 mol of water vapour and 0.20 mor of carbon monoxide are place in a 1.00 L reaction vessel. at equilibrium spectroscopic evidence shows that 0.10 mol of corbon dioxide is present calculate K for the reaction

28. ## Geomatry

A pilot flying at an altitude of 3500 feet sees a baseball field at an angle of depression on 35 degrees. what is the pilot's approximate horizontal distance, x, from the baseball field at this point? round your answer to the nearest foot.

Let's say that you and two partners want to start a company that specializes in special occasion gift baskets for individuals and corporate clients. You want to have a storefront in the local shopping mall or shopping area, as well as a vertual starfont on

30. ## chemistry

formic acid is a monoprotic acid with a ka at ml solutionof m of formic acid solution is titrated with m naoh what is the ph at the equivalence point

31. ## science

how do different liquids affect egg shells? Sounds like a worthy science project. Why don't you try some liquids and find out? Some might dissolve or soften them, some will change their color. wwell it depends on what type of liquid your useing like soda

32. ## math

Lolita saved \$ 5000 in a saving account which pays 12% interest compounded monthly. Eight months later she saved another \$ 5000. Find the amount in the account two years after her first saving.

33. ## physics

a sound wave has frequency of 631 Hz in air and a wavelength of 0.54m. what is the temperature of the air? assuming the velocity of sound at 0 degree celcius is 334 m/s. answer in units of celcius.

34. ## Calculus

Given that x=cos^2t and y=ln(sint) find d^2y/dx^2 at the point t=π/4

35. ## Math ASAP

Height: 10 inches Base Perimeter: 40 inches Lateral Surface Area: 400 square inches (^^^this is the total surface area of the sides) What is the Surface Area of the triangular prism?

36. ## trig

Find the exact value by using a half-angle identity. cos 22.5 degrees

37. ## Chemistry

What quantity of HNO3 can be neutralized by 0.1L of 0.50 m NaOH

list four things all living things do

39. ## chemistry

help balance this redox equation: HNO3 + Zn(s) NO(s) + ZnO ...i know i need H2O and possibly H+

40. ## MATH

FIND Y" if Y=ln(sec(x)+tan(x))

41. ## calc

Find the point on the graph of y = x2+1 that is closest to the point (3,1). d = √[(x-3)^2+(y-1)^2] d = √[(x-3)^2+(x^2+1-1)^2] d = √[(x-3)^2+(x^2)^2] d = [(x-3)^2+x^4]^1/2 d' = 1/2 [(x-3)^2+x^4)^1/2 [2(x-3)+4x^3] 0 = [1(2x-6+4x^2)] / [2√(x-3)^2+x^4]

42. ## statistics

2. Find the variance and standard deviation of the following sample. 0 -5 -3 6 4 -4 1 -5 0 3

43. ## chemistry

what is the mass (by difference) of a sample if the initial mass of the sample in the bottle was 29.89-g and the final mass of the bottle and sample was 22.01-g ?

44. ## Algebra 2

Please help me solve and find the excluded values for this problem. Also please show me the work for this problem I want to learn! h(x)=x^2-9/x^2-4x+3

45. ## physics

A ball is shot upward from the ground with an initial velocity of 12.0 m/s, along a y-axis that extends upward and that has its origin y = 0 on the ground. How much time does the ball take to move upward from y = 3.00 m to y = 5.00 m?

46. ## Math ASAP

Base Area: 22 square inches Lateral Surface Area: 308 square inches What is the Surface Area of the hexagonal prism?

47. ## Chemistry

What quantity of HNO3 can be neutralized by 0.1L of 0.50 m NaOH

48. ## possessive nouns

the chirps of the baby birds are quiet.

49. ## vector calculus

find an equation for the plane that contains the line x = 2t-8, y=3t +3, z= 5- t, and the point (5,4,0)

50. ## Stat

the teacher wants me to make a survey questions about a sample and get a statistical data from it, how? including variance and standard deveriation. thanks

51. ## chem

Explain the fact that acetic acid can be extracted quantitatively from ether solution by dilute aqueous sodium hydroxide solution.

52. ## english

how meny sea creaturs are dead

53. ## Physics

The MAVEN spacecraft, a NASA mission that is studying the Martian atmosphere, launched from Cape Canaveral in November 2013 on an Atlas V rocket. The rocket burns about 280,000 kg of fuel over 4 minutes (you can assume dm/dt is constant over that interval)

54. ## consumer math

how many feet are there in 24 yards

55. ## Algebra 2

Please help me solve and find the excluded values for this problem. Also please show me the work for this problem I want to learn!F(h) = x^2-9/x^2-4x+3

56. ## math

Find all pairs of numbers such that when they are added they equal 100, and when they are multiplied they are at least 2000.

57. ## math

By a unit fraction, we mean a rational number with a numerator of 1. Symbolically, 1 b where b is a nonzero integer. Find six distinct, positive unit fractions whose sum is 1.

58. ## math

50 red cars and 30 white and 20 blue what is the probability of 2 cars from the same colors ?

59. ## physics

does sunlight warm your body with light waves yes or no and why

60. ## algebra

A 400 g solution is 25% salt. How much salt must be added to produce a solution that is 40% salt?

61. ## algebra

A 400 g solution is 25% salt. How much salt must be added to produce a solution that is 40% salt?

when crating an interval for a requncy table-hoe do you determine the interval number-

63. ## math

to find the cordinates of the maximum or minimum point of a quadratic relationship?

64. ## biology

__Glycolysis is used to gain energy from glucose. How efficient is it (give an actual number) in its ability to get the energy from glucose into ATP? (assume the organism is undergoing anerobic fermentation). __You are studying a particular reaction in

65. ## math

the width of a rectangular painting is 2 meters less than the length, the area of the painting is 20 M^2

66. ## Health

Explain the relationship between hepatitis and virus?

67. ## Mathematics

How to use graphs to solve quadratic equations

68. ## physics

A marine siren consists of a cylinder 72 cm in length closed at one end.for sound through air at 336 m/s. find the lowest frequency of the siren

69. ## Calculus

Solve the differential equation: dy/dx = (3x^2) / (y+1) with initial conditions x = -1, y = 2 I have: ∫y + 1 dy = ∫3x^2 dx (y^2 / 2) + y = x^3 + C (2^2 / 2) + (2) = (-1^3) + C? 4 = -1 + C 5 = c (y^2 / 2) + y = x^3 + 5 Is this correct?

70. ## PHYSICS

A 3.50 kg ball with a velocity of 10.00 m/s collides with a stationary ball with a mass of 5.00 kg. After the collision, the first ball travels at a 42.6 degree angle from its original path, while the second ball travels at a -26.7 degree angle from the

71. ## Calculus

1) A telephone company has 10,000 phones in a certain city where the basic rate is \$4 per month. The officials have evidence that if the charge is reduced the number of phones will increase at an estimated rate of 1,000 phones for each 25 cent reduction.

72. ## Ã¡lgebra

What is the least perimeter of a rectangle with an area of 32 square feet?

73. ## math

Jennifer drove at steady speed for 2 hours then reduced speed by 10 mph and drove for another 3 hours what was the initial speed if the total distance was 220 miles?

74. ## math

2 over 5m-14=9+3 over 5m

75. ## chemistry

how many milligrams of calcium is in 1.229-g of calcium carbonate?

76. ## Algebra 2

Please help me solve and find the excluded values for this problem. Also please show me the work for this problem I want to learn!@!@!. 49X^6+7X^7/28X^8

78. ## algebra 2

Write in standard form (2b^2-b)+(b^2+4b-4) PLEASE EXPLAIN ON HOW TO DO IT I WANT TO LEARN

79. ## algebra 2

write in standard form. (2b^2b)+(b^2+4b-4)

80. ## physics

What is the distance between an object and its real image formed by a thin converging lens with focal length f = 14 cm, if the object distance is 60 cm? (b) What is the minimum object-image distance for a real image formed by that lens?

81. ## physics

If the water had lost 12000 joules and the calorimeter gained 1300 joules as the temperature of both rock and calorimeter increased from 22°C to 73°C and the mass of rock in the calorimeter was 189 grams, what is the specific heat, c, of the rock

82. ## Math ASAP

Base Area: 22 square inches Lateral Surface Area: 308 square inches What is the Surface Area of the hexagonal prism?

83. ## Math ASAP

Top Area: 26 square inches Top Perimeter: 34 inches Height: 11 inches What is the Surface Area of the 12-sided prism?

84. ## Math ASAP

Top Area: 13 square inches Total Surface Area: 346 square inches What is the Lateral Surface Area of the 5-sided prism?

85. ## Math ASAP

Base Area: 23 square inches Height: 11 inches What is the Volume of the hexagonal prism?

86. ## Math ASAP

Volume of Prisms: Volume: 150 cubic inches Top Area: 10 square inches What is the height? {5-sided prism}

87. ## project

i need to write projec about travel guide to Libay ?

88. ## Science

What is mantenrep?

89. ## math

what is the answer to 5z-1=?, 8s+4= etc. im thinking it is 5x3 (z=3)-1 equals 14. am I right?

90. ## Algebra

Find the roots of the given equation by completing the square. αx^2 + βx + δ = 0

91. ## Algbera

solve for the roots of the quadratic equation 2(x^2 - 4x + 5)=x^2 - x

92. ## algebra

Sam earns R1 350 per week doing tiling. How much does sam earn in an hour if he works 45 hours a week?

93. ## Pre-calculus

The problem is Find the difference quotient and simplify your answer F(x)=5x - x^2, F(5+h) - F(5) over h ^2 this means power of two

94. ## geometry

abcd is a rectangle such that ab=-3 radical sign 48+2 radical sign 75+4radical sign108 and Bc=4 radical sign 27 +radical sign 300 prove that abcd is a square

7x=5+5x

96. ## algebra

what is (34576=657)+364*4567divided by 45637*234869=? use a calculator

1. ## Math

c. supplies

posted on May 6, 2019
2. ## math

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posted on May 22, 2018
3. ## Science

2.0668

posted on February 11, 2018
4. ## chem - precipitation problems

H2s + Pb(NO3)2 : 2HNO3 + PbS But i am not sure of the average rate , can you please tell me the answer?

posted on January 1, 2018