1. Physics

An object is placed at a distance of 1.5 m from a screen and a convex lens is interposed between them. The magnification produced is 4. What is the focal length of the lens.

2. Physics

A billiard ball moving at 5.45 m/s strikes a stationary ball of the same mass. After the collision, the first ball moves at 4.81 m/s, at an angle of 28° with respect to the original line of motion. Find the velocity (MAGNITUDE and DIRECTION) of the second

3. Math

Carlene saves \$y. Sharon save 3 times as much money as Carlene. Jason saves \$50 more than Sharon. How much do they have altogether?

4. Physics

The spring shown in the figure is compressed 59cm and used to launch a 100 kg physics student. The track is frictionless until it starts up the incline. The student's coefficient of kinetic friction on the 30∘ incline is 0.14 . k= 80,000 N/m m=100 kg uk=

5. Spanish--1 question

Why is it not always necessary to include a subject pronoun before the verb in Spanish?

6. Calculus

A large container has the shape of a frustum of a cone with top radius 5m, bottom radius 3m, height 12m. The container is being filled with water at the constant rate of 3.9 m^3/min. At what rate is the level of water rising at the instant the water 9 m

7. Physics

A box of mass m and initial speed v0 slides distance d across a horizontal floor before coming to rest. Use work and energy to find an expression for the coefficient of kinetic friction.Express your answer in terms of the variables v0, d, and free fall

8. Trig

House B is located at a bearing of N67°E from house A. House C is 370 meters from house A at a bearing of S68°E. House B is located at a bearing of N11°W from house C. Find the distance from house A to house B. (Round your answer to two decimal places.)

9. Physics test review

A ball is thrown horizontally from the top of a building 30.1 m high. The ball strikes the ground at a point 66.8 m from the base of the building. The acceleration of gravity is 9.8 m/s2 . Find the time the ball is in motion. Answer in units of s Find the

10. Algebra

A kayaker paddles upstream for 1.5 hours then turns his kayak around and returns to his tent in 1 hour. He travels 3 miles each way. What is the rate of the rivers current?

11. Physics

A coin is placed on a large disk which rotates uniformly at a rate of 2 rot/s. The coefficient of friction between the coin and the disk is 0.1. To what distance from the center of the disk should the coin be placed so that the coin may not slip? I know

12. geometry

Eddie is arguing with tana about the probability of flipping three coins. They decided to flip a penny, nickel, and a dime. Which would be better determining the sample space, a tree diagram or an area model? Justify your answer.

13. calculus

A large container has the shape of a frustum of a cone with top radius 5 m, bottom radius 3m, and height 12m. The container is being filled with water at the constant rate 4.9 m^3/min. At what rate is the level of water rising at the instant the water is 2

14. Physics

A small sphere of mass 2 kg is attached to the end of a cord of length 2m and rotated in a vertical circle about a fixed point O. Determine the tension in the cord at the lowest point of the trajectory if the speed at this point is 7m/s. Use g=9.8 m/s2.

15. Physics

A small sphere of mass 3 kg is attached to the end of a cord of length 2m and rotated in a vertical circle about a fixed point O. Determine the tension in the cord at the uppermost point of the trajectory if the speed at this point is 8m/s. Use g=9.8 m/s2.

16. Calculus (math)

A boat leaves a dock at 2:00 P.M. and travels due south at a speed of 15 km/h. Another boat has been heading due east at 20 km/h and reaches the same dock at 3:00 P.M. How many minutes past 2:00 P.M. were the boats closest together?

17. Calculus (math)

A painting in an art gallery has height h and is hung so its lower edge is a distance d above the eye of an observer. How far from the wall should the observer stand to get the best view? (In other words, where should the observer stand so as to maximize

asked by Thanks to whoever solve this!
18. Physics

A small sphere of mass 1 kg is attached to the end of a cord of length 1 m and rotated in a vertical circle about a fixed point O. If the speed at the uppermost point of the trajectory is 1 m/s, the sphere will have a circular trajectory (will move in a

19. calculus

The Voltage v , Current I and Resistance R are related by the equation V=IR. Suppose that V is increasing at a rate of 2 volt/sec, while I is decreasing of the rate of 1/5 (amp/sec ). Let t denote time in seconds. Find the rate at which R is changing when

20. Calculus

Joshua jumps from a platform diving board that is 32 feet above the water. The position of the diver can be modeled by s(t) = -16t2+16t+32, where s is his position and t is the seconds that have gone by since he jumped. When does the diver hit the water,

21. Math Question

In △PQR, ∠R=90◦ ,∠P=58◦, and PR=7.1 cm. Determine the area of △PQR to the nearest tenth of a square centimetre.

22. Intermediate Algebra

A bank loaned out \$17,000 part of it at a rate of 6%per year and the rest at 14%per year. If the interest received in one year totaled \$1500 how much was loaned at 6%.

23. physics

. A 2.0 kg brick has the dimensions 7.5 cm x 15 cm x 30 cm. Find the pressure exerted by the brick on a table when it is resting on its various faces.

24. Math

In trapezoid CDEF, angle D = angle E=90degrees. Angle C =60 degrees, EF=4.5cm, and DE=3.5cm. What is the perimeter of the trapezoid to the nearest mm?

25. Accounting

On Jan.1, Pedigo Corporation purchased a small company and recorded goodwill of \$150,000. its useful life is indefinite. may 1- purchased for 475,000 a patent with an estimated useful life of 5 years and a legal life of 20 years.Prepare adjusting entries

26. Mechanical Behavior of Materials

The television coverage of the World Series showed several remarkable slow-motion views of the deflection of the bat as it hit the ball. Major league wood baseball bats are made of ash. A typical major league bat has a length of 0.95m and a tapering

27. socials studies 9

why do you think lawyers in the land claims trials refer to the royal proclamation of 1763 more than 200 years after it was proclaimed? I do not understand this question..

28. physics

A jet plane is flying with a constant speed along a straight line, at an angle of 25.5° above the horizontal, as Figure 4.30a indicates. The plane has weight vector W whose magnitude is 86500 N, and its engines provide a forward thrust vector T of 103000

29. Art History

The top rock on a dolmen is called the: A. bridge B. Henge C. Capstone D. Cairn I think it's C., but not sure

30. Mechanical Behavior of Materials

The creep compliance of a polymer is given below. A specimen of polystyrene is loaded in creep with a stress of 10MPa for 25hours and 30MPa for an additional 25hours and then unloaded. What is the creep strain after 75hours? t (hours) J(t) MPa-1 0 1.0 x

31. Mechanical Behavior of Materials

An atomic force microscope cantilever, of rectangular cross section, has a length, l, of 200μm, a width, b, of 20μm and a depth, h, of 1μm. It is made of silicon nitride, which has a Young's modulus, E, of 300GPa. What is the maximum force that can be

32. Chemistry

What would be the molarity of a solution made by dissolving 126g K3PO4 into 1500 mL of water?

33. Calculus

A marble is dropped from the top of the empire state building. a. Determine the position and velocity functions for the marble b. What is the average velocity for the first 3 seconds of flight? c. Whatisthespeedofthemarblewhent=0? t=3? t=6? d. How long

34. Mechanical Behavior of Materials

A helmet has an open cell polystyrene foam liner that is designed to absorb the kinetic energy from an impact. The foam has a relative density of 10% and the Young's modulus of the solid polystyrene that the foam is made from is 1.5GPa. How much energy per

35. Mechanical Behavior of Materials

Calculate the load that a fibroblast cell applies to buckle a single column in a collagen tissue engineering scaffold, given that the column has a length of 100μm, is circular in cross section, with a diameter of 2μm, and has a Young's modulus of 5MPa.

36. Mechanical Behavior of Materials

At a point in a plate subjected to plane stress loading along its surface, the cartesian stress components acting on the y-face of an element oriented along the (x,y) frame are σy=8MPa and τxy=16MPa, The maximum allowable tensile (normal) stress, to

37. algebra

Please Help Me Check My Work :) 1) Find the 5th term of - f(n)= 3(n-3) My answer- -279 2) Find the third term if the first term is 4 - f(n)= 2f(n-1)+2 My answer- 16 3) Find the third term using the explicit rule - f(n) 4-n/n+3 My answer- 1/6 4) Recursive

38. Science: Chemistry

1. The element gold, Au, has a face-centered cubic structure. (Density - 19.3 g/cm^3) (a) What are the # of gold atoms in 1 unit cell? (b) What are the # of unit cells in 1 mol? (c) What is the volume of 1 mol gold unit cells? (d) What is the volume of 1

39. Physics

A 1550 -kg car moves on a horizontal curved road. If the radius of the curve is 46 m and the coefficient of friction between the tires and road is 0.1, find the maximum speed the car can have so that it may not skid.

40. Physics

A 4.80kg cat leaps from the floor to the top of a 94.0-cm-high table. If the cat pushes against the floor for 0.230s to accomplish this feat, what was her average power output in hp during the pushoff period?

41. Chemistry

What is the density (in mg/mL) of a H2S gas at 12.9 atm and 137 K?

42. Art History

One fundamental change that marks the beginning of the Neolithic period is: A. year-found settlements. B. use of the bow and arrow. C. weaving D. use of stone tools I think it's A, but not sure.

43. Statistics

About 7% of men in the U.S. have some form of red-green color-blindness. Suppose we randomly select one U.S. adult male at a time until we find one who is red-green color-blind. How many men would we expect to choose, on average? Design and carry out a

44. Trigonometry

A telephone pole 40 feet high is situated on an 13° (H) slope from the horizontal. The measure of angle CAB is 21°. Find the length of the guy wire AC.

45. chemistry

3. If 5.20 g of HCl is added to enough distilled water to form 3.00 L of solution, what is the molarity of the solution? [Use molecular weight: HCl, 36.46 amu] 5.20/36.46= 0.1426 X 3.00=0.428 M IS THIS CORRECT

46. Chemistry

I'm having trouble understanding Boyle's Law and Dalton's law of partial pressures. Can anyone help me work this please? Thank you A sample of propane gas, C3H8, was collected over water at 22.5 ºC and 680. torr. The volume of the wet gas is 3.89 L. What

47. math

Concrete is made by mixing cement and sand in the ratio 3:1:15 how much sand would be needed to make 125 tonnes of concrete

48. math

An urn initially contains 5 white and 7 black balls. Each time a ball is selected, it’s color is noted and it is replaced in the urn along with two other balls of the same color. Compute the probability that (a) one black and one white is selected. (b)

49. Trigonometry

Round your answer to three significant digits. Use the distances shown in the following figure to determine the depth of the submarine below the surface of the water. Assume that the line segment between the surface ships is directly above the submarine.

50. Chemistry

1. The eleent gold, Au, has a face-centered cubic structure. (Density - 19.3 g/cm^3) (a) What are the # of gold atoms in 1 unit cell? (b) What are the # of unit cells in 1 mol? (c) What is the volume of 1 mol gold unit cells? (d) What is the volume of 1

Bill kicks a rock off the top of his apartment building. It strikes a window across the street 17 m away. The acceleration of gravity is 9.8 m/s2 . If the window is 22 m below the position where Bill contacted the rock, how long was it in the air? Answer

52. Math

Use inverse trigonometric functions to find a solution to the equation in the given interval. Then find solutions? cos x = -0.6 , 0

53. Intermediate Algebra

How much would you have to deposit today in order to have \$5000 in 4 years in a bank account that pays 5% annual interest rate

54. statistics

For a certain yes/no survey question, 55% of the respondents answered “yes”.     The null hypothesis is that the population is equally divided on this issue (50% yes and 50% no). The sample size is equal to your age.      For a significance

55. calculus

Use l'hopital's Rule to evaluate lim x in 0 of (4x(cos 6x-1 )) / sin 3x-3x

56. chemistry

Is it appropriate to call a soft drink an aqueous solution? Justify your answer.

57. Enlgish

I just need an explanation from the instructions. I am a bit confused about it. EITHER use EACH of these nouns in a sentence which shows a human trait or characteristic OR choose one noun and use it in FIVE different sentences showing five human traits for

58. Chemistry

How many hydrogen bonds can each (i) water and (ii) ice molecule form?

59. Finance

Here's another way to look at it. Suppose you want to borrow \$100,000. You choose a 30-year fixed rate loan at 7.5%, and pay one discount point (\$1,000), a 1% origination fee (\$1,000), and \$350 in other fees. Although the lender is giving you a loan for

60. Chemistry

What is the molarity of a solution made by mixing 213.6 ml of 1.5 M NaCl with 328 ml of 4.3 M NaCl?

61. Grammar

Think critically or critically think

62. Social Studies

information to show how the U.S. Constitution distributes and limits powers within the federal government.

63. Algebra 2

Solving By Factoring (x-8)(x-5)=x Please show work!!!!

64. Trigonometry

An airplane approaches an airport. At a certain time, it is 939 m high. Its angle of elevation measured from the airport is 19.5◦. To the nearest metre, how far is the plane from the airport?

65. Chemistry

What is the molar mass of a gas (96.0 g) in a 25.0 L container at 27.0 °C? The pressure inside the container is 3.04E5 Pa.

66. Intermediate Algebra

The average monthly benefit B for certain individuals is given by the equation B=18.75+585.72, where t is the number of years since 1990. In what year will the monthly benefit B exceed \$1050? That is, solve B>1050.

67. Physics

A ball is thrown horizontally from the top of a building 30.1 m high. The ball strikes the ground at a point 66.8 m from the base of the building. The acceleration of gravity is 9.8 m/s2 . Find the time the ball is in motion. Answer in units of s

68. English

He is proud that he is rich. ----------------- What is the part of speech of 'that he is rich'? Is it an adverbial clasue? Or is 'of' omitted before 'that'?

69. Physics with Calculus

The system shown in the figure is in static equilibrium. The rod of length L and mass M is held in an unpright position. The top of the rod is tied to a fixed vertical surface by a string, and a force F is applied at the midpoint of the rod. The

70. KCKCC

A researcher believes that the percentage of people who exercise in California is greater than the national exercise rate. The national rate is 20%. The researcher gathers a random sample of 120 individuals who live in California and finds that the number

71. Physics

A 24.00 kg block at rest on a horizontal frictionless air track is connected to the wall via a spring. The equilibrium position of the mass is defined to be at x=0. Somebody pushes the mass to the position x=0.3500 m, then lets it go. The mass undergoes

72. Trigonometry

Round answer to two significant digits A telephone pole 40 feet high is situated on an 13° (H) slope from the horizontal. The measure of angle CAB is 21°. Find the length of the guy wire AC.

73. MicroEconomics

an accountant claims that she has found a legal way for Beth to shelter \$3,000 of taxable income from the federal government. The maximum amount that Beth is willing to pay to learn this strategy and reduce her taxable income by \$3,000 is

74. Algebra 2

Solving By Factoring Help me with these problems. 2x(2x+1)=2 5x^2+34x=7 Please show work I want to learn!!!

75. mathematics

find the number in an A.P such that the sum of 1st and 3rd term is 12 and the product of 1st and 2nd is 24

76. calculus

This is a question related to L'hopital's rule. lim x -> -infinity of ((x)(e^x)) This thing is weird because I apply l'hopital's rule yet I never receive the correct answer which is supposedly = 0. It just stays in the form [-infinity * -infinity]. Anyone

77. Algebra 2

Solving By Factoring 7p^2-50p=-7 Please show work for I could learn.

78. S.S.

7. After 1965, black civil rights leaders found it difficult to A. now support Hispanic rights in the United States. B. protest the Vietnam War. C. enforce the new laws in the South. D. achieve economic equality in the North. It's not B.

79. physics

I'm working on my science fair project for 5th grade. I want to measure the speed of rotation from an Ice skater. What type of equipment would I need to use? I think a video camera, a bright dot on the skater's chest and some type counter software. That's

80. trig

if x is a positive acute angle, then express tan(180+x) as a function of x

81. math

which would be better for determining the sample space, a tree diagram or an area model? Justify your answer

82. Calculus

This is a question related to L'hopital's rule. lim x -> -infinity of ((x)(e^x)) This thing is weird because I apply l'hopital's rule yet I never receive the correct answer which is supposedly = 0. It just stays in the form [-infinity * -infinity]. Anyone

83. calculus

find the derivative of y y= 2 (22x+31)^(3/2)+ arctan((22x+21)^(1/2))+ln(11x+16)-22x-30

84. math

If a certain number is added to the numerator and denominator of 1113 , the result is 1011 . Find the number

85. history

2. Roosevelt addressed the struggles of industry with the National Industrial Recovery Act (NIRA). Which of the following was not one of the main components of this effort? African American labor assistance Public works projects National Recovery

86. Preschool Creative Thinking

A creative teacher should encourage and accept non-conformist behavior as long as it: a. constructive b. joyful c. age-appropriate d. inoffensive I thinking c, but the word encourage mad me think it might be a, because one should always encourage

87. arithmetic

the 20th sum of an arithmetic progression is -7 and the sum of the first 20 terms is 620. find the 1st and 30th terms i am looking at using S20 = a(1-rn)/l-r = 620. but i am reallys tuck and think i am very wrong. please help.

88. Economic

Beth is single and lives in New York. Beth earned \$280,000 in 2011. The following table shows the IRS tax rates for a single taxpayer in 2011 On Taxable Income .. Tax Rates up to \$8,500 10% From \$8,500 to \$34,500 15% From \$34,500 to \$83,600 25% From

89. Algebra 2

Find x,y,z 2x-3y+z=-1 2x-y+2z=6 5x-4y+3z=6 Please show work I want to learn!!!

90. chemistry

(3.0 x 10^4 ) ÷ (6.2 x 10^1) = 18.6x10^3 (4.7 x 10^-3 ) ÷ (9 x 10^-4) = 42.3x10^-7 (3.0 x 10^4 ) x (6.2 x 10^1) = 18.6x10^3 (5.1 x 10^2 ) x (3 x 10^4) = 15.3x10^-2

91. Mustapha

The oxidation number of kromium in k2Cr2O7

92. math

3x-2 + 2-x = - 1 ---- ---- -- 8 4 2

93. Algebra 2

Solving By Factoring 6x^2-13x=-6 (x-8)(x-5)=x 4x(x-6)-x(x-2)=-24 Please show work I want to learn!!!!!!

94. math

What is 1 plus 1

95. Chemistry

what are the simplest molecules to synthesize a n,n-dimethyl-2-methylpropanamine

96. Algebra 2

Solving By Factoring 4x(x-6)-x(x-2)=-24 Please show work!!!

97. maths

the denominator of a fraction is two more than the numerator.when we decrease the numerator by1 and increase the denominator by 3,we get 1/4.find the fraction

98. Calculus

what is x and cosh ln(x) when tanh(lnx^(1/2)= 12/13

100. human life

how does the human life cycle in a body

101. physics

A 2.7 kg object falls from a tower. It experiences 2.3 N of air resistance. What is the acceleration?

102. Maths

The pulley in the jib of a crane has a diameter of 56cm. Find: a) The circumference of the pulley b) The number of revolutions turned by the pulley when the crane raises a load through a vertical height of 44m.

103. math

2 six sided dice are throne together.what is the probability that a total of 10 is thrown.can u show me how to do please ,thanks

104. E.V.S

Project on there is great relationship between elnino and droughts of India.

105. math

Let r be a rational number. Is (ab)^r = a^r b^r for any real numbers a and b?

106. math

the bearing of P from Q is 60. what is the bearing of Q from P?

107. algebra

solve the equation for x -2(2x-2)=2x for y 9x+y=9 solve theinequality 2x-6