1. Physics

    A 69kg skateboarder, at rest on a frictionless surface, throws a 4.0kg rock with the velocity given by v=3(i hat)+4(jhat), where the x and y axes are both in the horizontal plane. What is the x component of the subsequent velocity of the skateboarder? WHat
  2. Physics

    The inner conductor of a coaxial cable has a radius of 0.900 mm, and the outer conductor's inside radius is 5.00 mm. The space between the conductors is filled with polyethylene, which has a dielectric constant of 2.30 and a dielectric strength of 18E6
  3. English

    Can you please check these sentences for me? Thank you. 1) Henry believes beauty to be not as superficial as thought. 2) He urges Dorian to enjoy his youth now that he can, while it won't last for ever. 3) He also urges him to give in to any kind of
  4. physics

    what are the units of wavelengh They can be any length units, but it is common to use meters for radio waves, centimeters for microwaves, micrometers for infrared, and nanometers or Angstroms (10^-8 cm) for visible and ultraviolet light. Regardless of what
  5. Physics

    Please help me with the following problem: Joe is on a cross-country trip from New York to Los Angeles. He drives for 45.0 min at 70.0 km/h, 10.0 min at 95 km/h, and 30.0 min at 55.0 km/h, and he spends 20.0 min eating lunch and buying gas. What is the
  6. physics # 2

    2. A particle of mass m and speed v collides at right angles with a very massive wall in a perfectly elastic collision. The magnitude of the change of momentum of the particle is a.) zero b.) mv/2 c.) mv d.) ã (2) mv e.) 2mv Hint: the final momentum is
  7. physics

    I did a projectile motion lab, predicting where a ball would land before actually dropping it. I have to answer this question: you accounted for variations in the velocity measurement in your range prediction. Are there other measurements you used which
  8. math

    6=e^5r I have no idea how to do this please help Thanks
  9. help i have no idea!!!!!!

    4( 34+5y-14-4y)=104
  10. Steve

    I have no idea how to do this: h t t p : / / t i n y u r l . c o m / y f e 9 8 s d
  11. math

    which is the least? 3/7, 2/5, 1/2, 1/3 I have no idea!
  12. physics

    You drop a rock from rest out of a window on the top floor of a building, 50.0 m above the ground. When the rock has fallen 3.80 m, your friend throws a second rock straight down from the same window. You notice that both rocks reach the ground at the
  13. SCIENCE HELP

    Can anyone anyone please help me or guide me to a web site where I can find this information? Thank you. Dolphin and porpoise populations are endangered by the _________ fishery. I have twenty questions to complete on my paper and I found all the answers
  14. physics

    A.An observer moving at a speed of 0.810 c relative to a rod measures its length to be 2.00 m and sees its length to be oriented at 30.0 degrees with respect to the direction of motion. What is the proper length of the rod? B.What is the orientation angle
  15. English

    I need help answeringthis question about a poem. i will write the instructions below..Thank you How does Martin Espada use imagery,setting, and figures of speech to convey the idea in " Latin Night at the Pawnshop"? the only problem i am having is
  16. English

    Hi there could you help me with this question from the novel to kill a mockingbird. Discuss the theme of personal intergrity in relation to the novel. Use examples of people who are involved in bringing out this theme. The task i am having difficulty with
  17. physics

    You drop a rock from rest out of a window on the top floor of a building, 50.0 m above the ground. When the rock has fallen 3.80 m, your friend throws a second rock straight down from the same window. You notice that both rocks reach the ground at the
  18. Chemistry

    What NaCl concentration results when 209 mL of an 0.660 M NaCl solution is mixed with 492 mL of a 0.270 M NaCl solution? __ mol/.209 L = 0.660 M __ mol/.492 L = 0.270 M .. I have no idea how to solve this. I have no idea why I even set up the equation
  19. Physics

    a shaft rotation @ 800 rpm delivers a torque of 240 N.m to an output shaft that is rotating @ 200 rpm. a. if the efficiency of the machine is 70%, compute the output torque b, what is the output power e=Po/Pi .7=x/240 N.m = 168 N.m this is not the answer
  20. physics

    As an environmentally friendly idea, some have proposed using the temperature gradient of the ocean to generate electricity. This system would use the temperature gradient between the surface of the ocean (at about 200 C) and the water temperature at a
  21. Physics

    As an environmentally friendly idea, some have proposed using the temperature gradient of the ocean to generate electricity. This system would use the temperature gradient between the surface of the ocean (at about 200 C) and the water temperature at a
  22. Physics

    What is the ratio of the wight of a man when he is in a tunnel 1000 km below the surface of the Earth to his weight at the surface? ...I'm not sure how to proceed, not because I don't know how to do it, but because I have no idea how to come up with a(g)
  23. physics

    A hydraulic jack in a gas station lifts a 900kg car a distance of .25cm When a force of 150N pushes a piston through a distance of 20cm Find the IMA (book answer is 80) AMA (book answer is 59) Efficency (book answer is 74%) can you help, I have no idea how
  24. College physics

    a person drives northward (90 degrees) at 15m/s in a truck that weighs 2500kg. a second person driving a car that weighs 1600 kg drives southwest (225 degrees) at 16 m/s. They have a perfectly inelastic collision. What is the direction and speed of the two
  25. social studies Hinduism

    Looking for information on hinduism: 1) Considering that Hiduism lacks a united belief system, what makes up the hindu religion? 2)What are the cultural and societal influences that have made hinduism vital to the region in which it originated? 3) Explain
  26. Math(Please help)

    Show that (f X g)(x) = (g X f)(x) = x for f(x)= 3x-5 and g(x)= x+5 / 3 I have know idea how to do this.
  27. Definition

    What does innovation mean? Does it just mean a new idea?
  28. algrebra

    16(5/8x+1/16)x=16(7/16+x) I have no idea how to multiple 5/8 by 16
  29. math

    Why is an idea like the pacific?
  30. Math 115

    16÷(-2)x 4 OVER 2^3 +4 I have no idea of how to do this
  31. Algebra 2

    What is f(-5)if f(x) = |2x - 1| + 10? 21 19 -1 -21 I have no idea how to solve this.
  32. Algebra

    SImplify: (x - 9/x) / (1 + x/3) and (m^-1 + n^-1) / (m^-3 + n^-3) I have no idea what to do
  33. math

    9 divided by 6/7 .. i have no idea how you do this so please help!
  34. Math(Please help)

    If (e^x)^-2 X (e^x)^2 X e^x = 1/e^2 find x? I have no idea how to do this
  35. Math

    If (e^x)^-2 X (e^x)^2 X e^x = 1/e^2 find x? I have no idea how to do this.
  36. Algebra

    Simplify (6x^-2)^2(0.5x)^4. I have no idea how to do this!, please help!
  37. grammar

    Concentration does not mean think one idea.
  38. Function Notations s

    I have no idea what to do here. [f(2)-f(1)]-[f(1)-f(0)] f(s)=s^2-6s-9
  39. health

    I have no idea what to do for a project can you help me?
  40. algebra

    I need help with doing this problem... 5x-7(2-4x). Any idea how to do it?
  41. Math

    why is an idea like the pacific?
  42. physics

    no idea how to do this problem A kid at the junior high cafeteria wants to propel an empty milk carton along a lunch table by hitting it with a 3.0g spit ball. If he wants the speed of the 40g carton just after the spit ball hits it to be 0.30 m/s, at what
  43. English

    1. She explained to me how to draw a dinosaur. 2. She explained how to draw a dinosaur to me. (Are both okay? Which one is better?) 3. Susan suggested to us a very good idea. 4. Susan suggested a very good idea to us. (Are both okay? Which one is better?)
  44. PHYSICS HELP PLEASE!

    The maximum wavelength of light emitted from a blackbody that will emit electrons from a given piece of metal is 255nm. What is the fraction of total energy emitted from the black body that emits electrons? I set up the integral:
  45. Physics

    A mass of 4.77 kg of chilled water at 0C is placed in a freezer which is kept at −19.2C. Approximately how much electric energy is needed to operate the compressor to cool this water to −19.2 C if the room temperature is maintained at
  46. ap physics

    I need some help with the following problems. I got no idea how to do it...PLEASE HELP!!!!THANKS A LOT!! A hunter is standing on flat ground between two vertical cliffs that are directly opposite one another. He is closer to one cliff than the other. He
  47. Physics E&M

    An electron is released from rest on the axis of a uniform positively charged ring, 0.100 m from the ring's center. If the linear charge density of the ring is +0.149 µC/m and the radius of the ring is 0.200 m, how fast will the electron be moving when it
  48. Physics

    Determine the work done by a person when lowering an object of mass 2.6 kg by a distance of 2.4 m. The person applies a force Fext such that the object moves with constant speed, i.e., without acceleration? My ans: W=F*d F = ma But it's saying constant
  49. SS

    What is the basis for the the economic theory of mercantilism that drove the exploration and settlement of North America by Europeans? Mercantilism is rooted in the idea that a nation’s power stems from the authority of an absolute monarch. Mercantilism
  50. Physics. LAST PROBLEM!!

    A small metal ball with a mass of m = 82.5 g is attached to a string of length l = 1.72 m. It is held at an angle of θ = 58.5° with respect to the vertical. The ball is then released. When the rope is vertical, the ball collides head-on and perfectly
  51. Physics

    Two acrobats, each of 50.0 kg, launch themselves together from a swing, holding hands. Their velocity at launch was 6.80 m/s and the angle of their initial velocity relative to the horizontal was 36.0 degrees upwards. At the top of their trajectory, their
  52. PHYSICS....PLEASE HELP

    Which of the following systems have high entropy? Which systems have low entropy? a. papers scattered randomly across a desk b. a freshly opened pack of cards c. a cultivated field of cabbages d. a room after a party Whomever designed this question doe not
  53. Biotechnology

    I need a couple of ideas. For the project we are supposed to test out an idea for biotechnology product that is innovative. However, it's just 2 pages, meaning that we can't "develop" something and thus it can include a lot of assumptions. Our choices
  54. physics

    Two boats start together and race across a 42 km wide lake and back. Boat A goes across at 42 km/h and returns at 42 km/h. Boat B goes across at 21 km/h, and its crew, realizing how far behind it is getting, returns at 63 km/h. Turnaround times are
  55. physics

    Two boats start together and race across a 42 km wide lake and back. Boat A goes across at 42 km/h and returns at 42 km/h. Boat B goes across at 21 km/h, and its crew, realizing how far behind it is getting, returns at 63 km/h. Turnaround times are
  56. physics

    Two boats start together and race across a 42 km wide lake and back. Boat A goes across at 42 km/h and returns at 42 km/h. Boat B goes across at 21 km/h, and its crew, realizing how far behind it is getting, returns at 63 km/h. Turnaround times are
  57. physics

    Two boats start together and race across a 42 km wide lake and back. Boat A goes across at 42 km/h and returns at 42 km/h. Boat B goes across at 21 km/h, and its crew, realizing how far behind it is getting, returns at 63 km/h. Turnaround times are
  58. Physics

    a) Why do athletes in jumping or throwing disciplines use an approaching run as part of their acceleration? b) Neglecting air resistance and aerodynamics, what would be the best angle of release in discus throwing? My ans: a) To increase horizontal
  59. physics

    A spherically symmetric object, with radius R = 0.700 m and mass M = 1.90 kg, rolls without slipping across a horizontal floor, with velocity V = 1.200 m/s. It then rolls up an incline with an angle of inclination θ = 40.0 deg and comes to rest a
  60. PHYSICS

    Using the motor principle explain why a motor is rotating in the direction indicated. I seriuosly have no idea, please help explain this theory to me. PHYSICS - drwls, Saturday, February 6, 2010 at 2:15pm To help you answer that question, I'd need a figure
  61. Physics

    Imagine a vessel containing 2.000 kg of liquid whose specific heat equals 1.50 kcal/kg/°c. Suposse that all of the liquid exists at its vaporization temperature of 450 k. We transfer 150 cal of heat energy to the liquid. What is the temperature of the
  62. physics

    A space probe is to be put into a circular orbit of radius 42.00 km about an asteroid. At this radius the magnitude of the gravitational acceleration, normally referred to as the "gravitational field", is 1.00×10-3 meters per second squared. What speed,
  63. Physics (Mechanics)

    A uniform plate of height H= 0.69 m is cut in the form of a parabolic section. The lower boundary of the plate is defined by: y= 1.10x^2. The plate has a mass of 5.62 kg. Find the moment of inertia of the plate about the y-axis. Alright, I've done this so
  64. introduction to economices

    Explain the idea of SE and IE
  65. ap calc

    If f(x)=e^x, g(x)=sin(x), and h(x)=f(g(x)), then h'(pi/2)=? Please help I have no idea how to solve
  66. Math

    What is the value of x/yz if x= -2, y= -3, and z= -4? A. 6 B. -6 C. 1/6 D. -1/6 I have no idea how to work this out. Can someone walk me through this?
  67. english

    i need 4 symbols that represnt me and i have no idea how to know what they are
  68. Math equation

    I have no idea how to solve this. f(x)=3x-4 a) f(10) b) f (-2) c) f (0) d) (b)
  69. Calculus 1

    Calculate f'(-1) f(x) = x^7 * h(x) h(-1) = 5 h'(-1) = 8 Answer is 27, but I got no idea how to get there.
  70. Science

    I need an idea for an essay about muscles
  71. English

    I need to write an essay but have no Idea where to go with it.
  72. English

    I need to how to unscramble: nutxee No Idea what it is PLEASE HELP!
  73. philosophy

    what makes an idea dangerous?
  74. Postmodernism

    Hi! It says describe an idea or theory IN postmodernism. What theory or idea can I describe?
  75. Math

    Given f(x) and g(x)=f^-1(x). If f(1)=4 and f'(1)=-3, then find g'(4). ...No idea where to start with this. Please help? Thanks much!
  76. Chemistry

    the idea expressed in whims is known as
  77. algebra I

    Please help I have no idea where to start. Solve for h 5h + 5+ 4h = 36
  78. math

    i need Help i have no idea how to simplify this expression! x/x+5 + 7x+10/x^2+5x
  79. Algebra III

    3^2x - 6 x 3^x + 9 = 0 Solve for x I have no Idea what to do
  80. biology

    What is the main idea of metabolism. please help
  81. MATH

    Does anybody has any idea how does 2(tan( θ)-θ)+C become 2[((√x^2-4)/2)-sec^-1*(x/2)]+C
  82. Algebra 2

    (a+3)^2/a-3/5/(a^2-9)= Pls help have no idea where to start
  83. English

    I need a idea for a propaganda poster? It can be anything
  84. chemistry

    what is the big idea of energy?
  85. chemistry

    what is the 'big idea of energy'???!
  86. history

    who came up with the idea of the school bus?
  87. acting

    Hi i was wonder how to become in actor any idea ? will be helpful
  88. Chemistry

    what is the big idea of energy
  89. Calculus

    What are the antiderivites of x/ (x^2 (squareroot of x^4-1)) and 1/ (1+(x^2/4)) no idea :{
  90. Calculus

    If f(x) = integrate t^2 from x to x^2, then f'(x)= f'(-1)= Please help! I have no idea how to approach this.
  91. physics

    Two spherical objects are separated by a distance of 2.41 x 10-3 m. The objects are initially electrically neutral and are very small compared to the distance between them. Each object acquires the same negative charge due to the addition of electrons. As
  92. Language Arts

    Passage: "Harriet Tubman: Conductor on the Underground Railroad" by Ann Petry 1) What is the implied main idea of the passage? A) Harriet and the fugitives only survived because of the kindness of others. B) Harriet worked hard to ensure the fugitives
  93. Martin Luther King

    Hey guys could you help me with a better sentence than this. "In a competition the usual suspect of an offense towards the other player is the contender but Martin Luther King's death was not about the person who did it but the idea behind why he did it
  94. Physics

    Two steel blocks are at rest on a frictionless horizontal surface. Block X has a mas of 3.0 kg ans is attacthed by means of a light taut string to block Y that has a mass of 12 kg. A force of 45 N (E) is applied to block x. Calculate the force block Y
  95. physics

    What is the kinetic energy of each electron in a beam of electrons if the beam produces a diffraction pattern of a crystal which is similar to that of a beam of 1.00 eV neutrons? Note: The electron mass is 9.11 × 10–31kg; and the neutron mass is 1.67 ×
  96. Physics-Please check and I need help

    Please help set this up- A person goes into the electric field and has an object with a charge value of 4.2E-6C. At a distance of 10m from the object that's responsible for the elctric field, the person sees a force of 8.0N on the object they have. What is
  97. Physics

    A fullback preparing to carry the football starts from rest and accelerates straight ahead. He is handed the ball just before he reaches the line of scrimmage. Assume that the fullback accelerates uniformly (even during the handoff), reaching the line with
  98. Physics

    Orange light (wavelength=600nm) is passes through a single slit. Use a=2000nm and L=2m. a) Determine the linear size on the screen of the 2nd maximum (not including the central maximum). b) Determine how many total maxima occur in the pattern. a) I thought
  99. Physics

    Orange light (wavelength=600nm) is passes through a single slit. Use a=2000nm and L=2m. a) Determine the linear size on the screen of the 2nd maximum (not including the central maximum). b) Determine how many total maxima occur in the pattern. a) I thought
  100. Physics Drwls

    I was wanting help with my physics post and since no one replied I thought there wasn't a physics tutor on Jiskha, but came back on today cause I really need to get a hang of my physics stuff and luckily seen you Drwls. A bike rider approachea a hill with