1. physics

    At a playground, a 19.8 kg child plays on a slide that drops through a height of 2.13 m. The child starts at rest at the top of the slide. On the way down, the slide does a nonconservative work of -319 J on the child. What is the child's speed at the
  2. physics

    At a playground, a 19.7-kg child plays on a slide that drops through a height of 2.29 m. The child starts at rest at the top of the slide. On the way down, the slide does a nonconservative work of -368 J on the child. What is the child's speed at the
  3. mechnical

    1. A small fly wheel fitted to a motor with a moment of inertia of 80 kg m² slows down from 9000 rpm to 5500 rpm in 7.5 seconds. For the fly wheel, calculate: • The rate of deceleration which you can assume to be constant • The braking torque. 2.If
  4. Physics

    A girl is sledding down a slope that is inclined at 30º with respect to the horizontal. The wind is aiding the motion by providing a steady force of 131 N that is parallel to the motion of the sled. The combined mass of the girl and the sled is 59.9 kg,
  5. physic

    Block _____ Name ________________________________________ Date __________ Average Speed 1. In the 2008 Summer Olympics, Usain Bolt won the 100-m race in 9.69 s. What was his average speed? 2. Light from the sun reaches Earth in 8.3 min. The speed of light
  6. trigonometry

    a captive balloon is connected to a ground station A by a cable of length 842 ft inclined 65 degrees to the horizontal. In a vertical plane with the balloon and its station and on the opposite side of the balloon from A, a target B was sighted from the
  7. math

    a captive balloon is connected to a ground station A by a cable of length 842 ft inclined 65 degrees to the horizontal. In a vertical plane with the balloon and its station and on the opposite side of the balloon from A, a target B was sighted from the
  8. trigonometry

    a captive balloon is connected to a ground station A by a cable of length 842 ft inclined 65 degrees to the horizontal. In a vertical plane with the balloon and its station and on the opposite side of the balloon from A, a target B was sighted from the
  9. math

    A cuboid measures 6cm long, 5cm wide and 4cm high. What is the total length of the edges in centimeters?
  10. dynamics

    If it is released from rest at a height of h = 2 ft from the top of the uncompressed spring, determine the speed of the collar after it falls and compresses the spring 0.9ft .
  11. Math

    Okay .. i have a trig question for some floor plans that im trying to do. I have a right angle . /| / | c / | a /___| b I have the lengths of side c and b. Both Being 28ft in length. What is the length of side a? The way you have drawn it, or tried to draw
  12. Physics

    A test rocket is launched by accelerating it along a 200.0-m incline at 1.25m/s2 starting from rest at point A (the figure (Figure 1) .) The incline rises at 35.0 ∘ above the horizontal, and at the instant the rocket leaves it, its engines turn off
  13. Physics

    A test rocket is launched by accelerating it along a 200.0-m incline at 1.25m/s2 starting from rest at point A (the figure (Figure 1) .) The incline rises at 35.0 ∘ above the horizontal, and at the instant the rocket leaves it, its engines turn off
  14. Math (Calculus)

    Tower 1 is 60 ft high and tower 2 is 20 ft high. The towers are 140 ft apart. A guy wire is to run from point A to the top of each tower. [See a picture of this situation on page 274 of the textbook.] How many feet from tower 1 should point A be so that
  15. Physics

    . A stone is dropped from the top of a building that is 500m high. Disregarding air resistance how long does it take the stone to reach the ground?
  16. physics

    A tennis ball is thrown horizontally at a speed of 10 m/s from the top of a building 78.4 meters high. How long does it take the ball to hit the street?
  17. PHYSICS URGENT! PLEASE FRICTION CASE 2

    A 13 kg box is at rest on a level floor. The coefficient of static friction µS = 0.9 and the coefficient of kinetic friction µK = 0.8. Audrey is applying a 140 N push at an angle (=20°) as shown in Figure 1. C) What is the magnitude of FNormal on box
  18. physics

    Consider the system shown, with m1 = 2.0 kg, m2 = 3.0 kg, and α = 30o. The force F acts horizontally to the left and the kinetic coefficient of friction between m1 and the incline is μk = 0.40. The mass m2 is moving up at a constant speed. (a)
  19. maths-Arithmetic progression

    A ladder has rungs 25 cm apart.The rungs decrease uniformly in length from 45 cm at the bottom to 25 cm at the top.If the top and the botom rungs are two nd a half metre apart, what is the length of the wood required for the rungs
  20. Chemistry-Help Please

    Help please. Am doing a past exam paper and I hit a road block with this question: Chloride in a brine solution is determined by a precipitation titration. A 10.00 mL aliquot of the solution is titrated with 15.00mL of standard 0.1182 M AgNO3 solution. The
  21. insurance prep

    1. The information for Blocks 1 9 on the CMS-1500 can be obtained Customer Question Ask your own question now > 1. The information for Blocks 1–9 on the CMS-1500 can be obtained from the A. ledger card. B. medical treatment record. C. confidential
  22. Math

    The Pack-U-Up Moving Company uses several different size boxes,but the boxes all have the same meaurements on the top andbottom so they'll stack neatly on top of one another.The only differences between the boxes is their heights: some are three feet high,
  23. physics

    A 0.349 kg particle slides around a horizontal track. The track has a smooth, vertical outer wall forming a circle with a radius of 1.68 m. The particle is given an initial speed of 8.66 m/s. After one revolution, its speed has dropped to 6.05 m/s because
  24. physics

    A concrete block of mass 244 kg hangs from the end of the uniform strut of mass 45.0 kg. Angle ϕ = 30.0° and è = 45.0°. (a) Find the tension T in the cable. N (b) Find the horizontal component of the force on the strut from the hinge. N (right) (c)
  25. physics

    A concrete block of mass 244 kg hangs from the end of the uniform strut of mass 45.0 kg. Angle ϕ = 30.0° and è = 45.0°. (a) Find the tension T in the cable. N (b) Find the horizontal component of the force on the strut from the hinge. N (right) (c)
  26. Physics

    A block attached to a spring with unknown spring constant oscillates with a period of 7.0 s. Parts a to d are independent questions, each referring to the initial situation. What is the period if... The mass is doubled? The mass is halved? The amplitude is
  27. Physics - Work and Energy

    Jane, looking for Tarzan, is running at top speed (3.6 m/s) and grabs a vine hanging vertically from a tall tree in the jungle. How high can she swing upward? Does the length of the rope matter?
  28. Physics

    A coin rests 18.0 cm from the center of a turntable. The coefficient of static friction between the coin and turntable surface is 0.390. The turntable starts from rest at t = 0 and rotates with a constant angular acceleration of 0.850 rad/s2. (b) At what
  29. Physics

    A 16 kg mass is attached to a cord that is wrapped around a wheel with a radius of 10.9cm. The acceleration of the mass down the frictionless incline is measured to be 1.4 m/s2.The angle of incline is 36 degrees. Assume the axle of the wheel to be
  30. Physics please HELP

    An insulating sphere of mass m and positive charge q is attached to a spring with length h and spring constant k_s and is at equilibrium. An infinitely long wire with positive linear charge density lamda is placed a distance l away from the charged mass at
  31. physics

    A Boeing 787 is initially moving down the runway at 3.0 m/s preparing for takeoff. The pilot pulls on the throttle so that the engines give the plane a constant acceleration of 1.7 m/s2. The plane then travels a distance of 1900 m down the runway before
  32. math

    Mike was bored so he played with some colored blocks arranging them in a role he put 1 block in the first row 2 blocks in the second roll, 4 blocks and the third row and 8 blocks in the fourth row. If this pattern continues, how many blocks will Mike put
  33. please help with economics!

    Hi, please help me with this econs question! thanks! I'm asked to sketch the average and marginal cost curves of a software company, in which when it first starts up, the costs are extremely high. (High start up costs, millions of dollar spent to make the
  34. Economics

    Hi, please help me with this econs question! thanks! I'm asked to sketch the average and marginal cost curves of a software company, in which when it first starts up, the costs are extremely high. (High start up costs, millions of dollar spent to make the
  35. math

    I have 14 questions and I was wondering if someone could check my answers. This is a do or die situation. If I don't get an A, I may not get to graduate. I really appreciate you taking your time to double check theses for me. Thanks if you do. I know its a
  36. math word problems

    A ladder is leaning against a building. The distance from the bottom of the ladder to the building is 9 ft less than the length of the ladder.how high up the side of the building is the top of the ladder if that distance is 2 ft less than the length of the
  37. trigonometry

    R and S are in the same horizontal plane as the base of a cliff, but R is 132.6 meters nearer it than is S. They find the angles of elevation of the top of the cliff to be 32 degrees and 36 minutes and 63 degrees and 13 minutes. how high is the cliff?
  38. Physics

    A person is standing at the top of a 58.0m tall hill. He stumbles and falls.As he rolls down the hill, magically friction has no effect on him! When he is still 25.0m above the base of the hill determine how fast he is moving.
  39. physics

    a person is standing at the top of a 58 m tall hill. He stumbles and falls. As he rolls down the hill, magically friction has no effect on him! when he is still 25.0 m above the base of the hill determine how fast he is moving.
  40. math

    a tower 7 metres high stands on top of building which is 9 metres high. An observer at the bottom of the building notices that, as she walks away from the building, the angle theta which the tower subtends at her eyes seems to increase in size for a
  41. Physics

    A plane with a velocity of 111. 9 meters per second at a maximum rate of 6.8 m/s^2 the plane touches the runaway what's the minimum time before it can come to rest? A=6.8m/s^2 V=111.9m/s t=?
  42. Physics

    At a playground, a 18.7 kg child plays on a slide that drops through a height of 2.07 m. The child starts at rest at the top of the slide. On the way down, the slide does a nonconservative work of -318 J on the child. What is the child's speed at the
  43. Physics

    At a playground, a 18.7 kg child plays on a slide that drops through a height of 2.07 m. The child starts at rest at the top of the slide. On the way down, the slide does a nonconservative work of -318 J on the child. What is the child's speed at the
  44. Physics

    What should the theoretical maximum value of the uniform acceleration of a object freely rolling down an inclined plane and what would the angle of elevation be?
  45. English

    Can someone please help me proof read my paper and help me to know where my errors are and how I can better this paper? Is this good for a descriptive essay? Is their something I should elaborate more or less on? Are my paragraphs ok or do I need to
  46. Physics

    (1) A virtual image -7 cm tall and 17 cm away from a mirror is created by an object 7 cm away from a mirror. How tall is the object? What kind of mirror created the image? What is its focal length? (2) If a 1.75 m tall man is looking at a plane mirror from
  47. Physics

    (1) A virtual image -7 cm tall and 17 cm away from a mirror is created by an object 7 cm away from a mirror. How tall is the object? What kind of mirror created the image? What is its focal length? (2) If a 1.75 m tall man is looking at a plane mirror from
  48. physics

    please show me in steps how to solve this thanks alot! A bobsled zips down an ice track, starting from rest at the top of a hill with a vertical height of 150m. Disregarding friction, what is the velocity of the bobsled at the bottom of the hill? (g=9.81
  49. Physics

    A skier of mass 110 kg travels down a frictionless ski trial. a.) If the top of the trail is a height 200m above the bottom, what is the work done by gravity on the skier? b.) Find the velocity of the skier when he reaches the bottom of the ski trail.
  50. Constitution

    if an amendment violates the constitution,why should the Supreme court block its ratification? How can an amendment violate the constitution? THe amendment once adopted is a PART of the consititution. Now proposed amendments are all unconstitutional
  51. geology

    is this ok? harry hess studied the arced chains of islands with active volcanoes. in 1953 he discovered the great global rift. he is also know for his theriores on the sea floor spreading. alfred Wegener. alfred is remembered by his theory of the
  52. Physics

    A box with a mass of 4.0kg is sitting on a plane angled at 60degrees above the horizontal. The coefficient of friction between the box and the plane is 0.3. What is the horizontally applied force necessary to stop the box from sliding down the ramp?
  53. physics

    You spot a plane that is 1.63 km north, 2.3 km east, and at an altitude 5.2 km above your position. 1) How far from you is the plane? 2) At what angle from due north (in the horizontal plane) are you looking? 3) Determine the plane's position vector (from
  54. physics

    A freight train has a mass of 3.1 × 107 kg. If the locomotive can exert a constant pull of 4.9 × 105 N, how long would it take to increase the speed of the train from rest to 71.9 km/h? Disregard friction.
  55. Physics

    A freight train has a mass of 1.7 × 10^7 kg. If the locomotive can exert a constant pull of 5.2 × 10^5 N, how long would it take to increase the speed of the train from rest to 74.6 km/h? Disregard friction. Answer in units of s
  56. physics

    A freight train has a mass of 3.2 × 107 kg. If the locomotive can exert a constant pull of 7.1 × 105 N, how long would it take to increase the speed of the train from rest to 74.6 km/h? (Disregard friction.)
  57. pig question (PHYSICS)

    Hello, a slide loving pig slides down a certain 35° slide in twice the time it would take to slide down a frictionless 35° slide. What is the coefficient of kinetic friction between the pig and the slide? Is this the equation on how to solve it? It's
  58. Math

    A certain mass is supported by a spring so that it is at rest 0.5 m above a table top. The lowest position of the mass is 0.1 m, and the highest position is 0.9 m. The mass is pulled down 0.4 m at time =0, creating a periodic up and down motion. It takes
  59. BUSINESS RESEARCH

    A data processing analyst for a research company finds that a preliminary computer run of survey results that his company conducted for a client show that consumers love the client's new product. Based on that information, the analyst buys a large block of
  60. physics

    While a roofer is working on a roof that slants 36 degrees above the horizontal, he accidentally nudges his 85.0 N toolbox, causing it to start sliding downward, starting from rest. If it starts 4.25m from the lower edge of the roof, how fast will the
  61. Physics Important please

    An insulating sphere of mass m and positive charge q is attached to a spring with length h and spring constant k_s and is at equilibrium. An infinitely long wire with positive linear charge density lamda is placed a distance l away from the charged mass at
  62. physics

    4. A beam of light in water enters a plastic block (index of refraction=1.40(a) if the angle of incidence is 40, what is the angle of refraction in the plastic?(b) at what angle must the beam be incident on the plastic if the refraction angle is to be 30?
  63. physics

    A lumberjack (mass = 95.7 kg) is standing at rest on one end of a floating log (mass = 218 kg) that is also at rest. The lumberjack runs to the other end of the log, attaining a velocity of +2.54 m/s relative to the shore, and then hops onto an identical
  64. physics

    An ore car of mass 37000 kg starts from rest and rolls downhill on tracks from a mine. At the end of the tracks, 28 m lower vertically, is a horizontally situated spring with constant 2.8 × 10 5 N/m. The acceleration of gravity is 9.8 m/s 2 . Ignore
  65. physics

    A car of mass 1000 kg is on an icy driveway inclined at an angle of 33◦. The acceleration of gravity is 9.8 m/s^2 θ If the incline is frictionless, what is the acceleration of the car?
  66. mah

    holly spend 7 and 3/5 hours in school each day. her lunch period is 1/2 hour long, and she spends a total of 7/10 hour switching rooms between classes.the rest of her day is spent in 6 classes that are all same length. how long is each class?
  67. mah

    holly spend 7 and 3/5 hours in school each day. her lunch period is 1/2 hour long, and she spends a total of 7/10 hour switching rooms between classes.the rest of her day is spent in 6 classes that are all same length. how long is each class?
  68. Physics! Rolling Masses! HELP

    The five masses below all have the same radius and a cylindrically symmetric mass distribution. They start to roll down an inclined plane, starting from rest, at the same time and from the same height. Give their order of arrival at the bottom. (a) Icm=935
  69. physic

    Hi!Question:Two packing crates of masses m1 = 10.0 kg and m2 = 6.50 kg are connected by a light string that passes over a frictionless pulley as in the figure below. The 6.50 kg crate lies on a smooth incline of angle 45.0°. Find the acceleration of the
  70. sjc coolege

    A steel bar 10m long and 10cm ×2.5cm in section .It is subjected to an axial pull of 250KN. Determine the intensities of normal and tangential stresses on a plane.
  71. Physics

    During the investigation of a traffic accident that occurred in a 25 m/s zone, police find skid marks 60.0 m long corresponding to the distance the car traveled while braking to a halt. They determine that the coefficient of friction between the car's
  72. physics

    Roger pushes a box on a 30° incline. If he applies a force of 60 newtons parallel to the incline and displaces the box 10 meters along the incline, how much work will he do on the box?
  73. physics

    Two blocks of masses M and 3M are placed on a horizontal, frictionless surface. A light spring is attached to one of them, and the blocks are pushed together with the spring between them as shown in the figure below. A cord initially holding the blocks
  74. physics

    Two blocks of masses M and 3M are placed on a horizontal, frictionless surface. A light spring is attached to one of them, and the blocks are pushed together with the spring between them as shown in the figure below. A cord initially holding the blocks
  75. physics

    Responding to an alarm, a 100 kg, a fireman slides down a pole to the ground floor, 3.1 m below. The fireman starts at rest and lands with a speed of 3.8 m/s. Find the average force exerted on the fireman by the pole. Find the average force exerted on the
  76. physics

    10. A 2-kg object is moving at 3m/s. A 4-N force is applied in the direction of motion and then removed after the object has traveled an additional 5m. The work done by this force is: A. 12 J B. 15 J C. 18 J D. 20 J E. 38 J ans: D 11. A sledge (including
  77. Math

    A box contains 8 white balls, 7 black and 4 red. How many red balls must be added to the box so that the probability is 3/4? How many black balls need to be added so that it is 1/4? Thanks I have a mental block with this.
  78. math

    If a ball is thrown straight up from the top of a building that is 407 feet high, the position in feet above the ground is given by the function s(t) = -16t^2 + 75t + 407 where t is the number of seconds elapsed. a. How high is the projectile after 3
  79. Physics

    Can someone please check my answers for the first three questions and help me with the last one? 1)A racecar accelerates from rest at +7.2 m/s2 for 4.1 seconds. How fast will it be going at the end of that time? Answer: 29.5 m/s 2)A racecar starts from
  80. physics

    A physics professor is going ice skating for the first time. She has gotten herself into the middle of an ice rink and cannot figure out how to make the skates work. Every motion she makes simply cause her feet to slip on the ice and leaves her in the same
  81. TOm

    Hello, this is the last question that I can't seem to or be able to solve: 1. Jenny (75 kg) goes on a ski trip. She goes down a slope that's inclined at 15*. The drag coefficient of Jenny is 0.300, the surface of contact with air is 0.750 m^2 and the air
  82. physics

    A skier leaves the top of a ski ramp at an angle of 25 degrees with an initial velocity of 10 m/s. The ramp is 60 m high, neglecting air resistance determine:
  83. physics

    a ball is launched from the top of a 23 m high cliff with a velocity of 33 m/s oriented 12 degrees above the horizonal. Determine the time it takes for the ball to hit the ground.
  84. Science

    which would be the most likely forms that you would consider using within the next year? What personal advantages or disadvantages would prompt your decision? Thank you for using the Jiskha Homework Help Forum BUT your question is unclear. When you refer
  85. physics

    Two infinitely-long lines of charge run parallel to the z axis. One has positive unifonn charge per unit length, IvO, and goes through the x y plane at x=O, y=s/2. The other has negative unifonn charge per unit length, -A, and goes through x=O, y=-s/2.
  86. Please help Physics!!!

    Two infinitely-long lines of charge run parallel to the z axis. One has positive unifonn charge per unit length, IvO, and goes through the x y plane at x=O, y=s/2. The other has negative unifonn charge per unit length, -A, and goes through x=O, y=-s/2.
  87. Math, Analytic Geometry

    Derek wants to determine the height of the top of the backboard on the basketball goal at the playground. He places a standard 12-inch ruler next to the goal post and measures the shadow of the ruler and the backboard. If the ruler has a shadow of 10
  88. Penn foster high school.

    4. When sewing a new dress for yourself, the best method of marking the hem length is to A. pin it an even distance from the waistline. B. do it yourself with an adjustable hem marker. C. ask someone to mark it for you. D. chalk an even line from the lower
  89. physics

    "By means of a rope, whose mass is negligible, two blocks (mass: 11kg and 44 kg) are suspended over a pulley. The pulley can be treated as a uniform solid cylindrical disk. The downward acceleration of the 44 kg block is observed to be exactly one half the
  90. physics

    "By means of a rope, whose mass is negligible, two blocks (mass: 11kg and 44 kg) are suspended over a pulley. The pulley can be treated as a uniform solid cylindrical disk. The downward acceleration of the 44 kg block is observed to be exactly one half the
  91. Physics

    ball starts from rest under constant acceleration. If it travels a distance of 20.0 cm after time t, how far from the starting point is it after time 2t? Answer 40.0 cm. 60.0 cm. 80.0 cm. 100.0 cm. More information is needed to answer this question.
  92. P H Y S I C S

    A lumberjack (mass = 98.3 kg) is standing at rest on one end of a floating log (mass = 258 kg) that is also at rest. The lumberjack runs to the other end of the log, attaining a velocity of +3.69 m/s relative to the shore, and then hops onto an identical
  93. Physics

    A skater with an initial speed of 5.90 m/s stops propelling himself and begins to coast across the ice, eventually coming to rest. Air resistance is negligible. (a) The coefficient of kinetic friction between the ice and the skate blades is 0.125. Find the
  94. pre-calculus

    A plane flies at a speed of 150mph at an angle of 10 degrees, after 6 seconds, the plane keeps the same speed but changes to an angle 18 degrees. How long in minutes would it take the plane to travel to a cruising altitude of 30,000 feet?
  95. Math

    Derek wants to determine the height of the top of the backboard on the basketball goal at the playground. He places a standard 12-inch ruler next to the goal post and measures the shadow of the ruler and the backboard. If the ruler has a shadow of 10
  96. Probability and Statistics

    For questions 6 - 10 use the chi-squared distribution to test the hypothesis. 6) A restaurant owner wants to see if the business is good enough for him to purchase a restaurant. He asks the present owner for a breakdown of how many customers that come in
  97. Maths

    You wonder what altitude the plane reached when it was directly above the end of the runway and how far it travelled to get to that point. You know the runway tarmac is 5500 metres long and approximate that when the plane left the ground, it took off at an
  98. Physics

    A package is thrown down a curved ramp as shown in the figure. The package moves from A to B through a quarter-circle with radius R=3.00m. The mass of the package is 25.0kg. The package starts from rest at point A and there is no friction. A) Find the
  99. physics

    Two non-parallel light rays initially converge to a single point on a screen. A rectangular block of glass is now placed somewhere in front of the screen, in the path of the light rays, so that the glass surface is parallel to the screen. Where is the new
  100. trig

    A plane is flying 12,000 feet horizontally from a tall, vertical cliff. The angle of elevation from the plane to the top of the cliff is 45degrees, while the angle of depression from the plane to a point on the cliff at elevation 8000 feet is 14degrees.