Posts by joy

Total # Posts: 968

  1. physics

    A harmonic wave with a frequency of 90 Hz and an amplitude of 0.025 m travels along a string to the right with a speed of 20 m/s. a)Write a suitable sine wave function for this wave in terms of x and t. b) Find the maximum speed of a point on the string. (c) Find the maximum ...
  2. physics

    A physical pendulum in the form of a thin rod of length 1.04 m is pivoted at point P, a distance x from the pendulum's center of mass. Find the value of x for which the period of the pendulum will be a minimum.
  3. physics

    A simple harmonic oscillator's velocity is given by vy(t) = (0.86 m/s)sin(11t ? 5.55). Find the oscillator's position, velocity, and acceleration at each of the following times. (Include the sign of the value in your answer) a) t = 0s b) t = 0.5s c) t = 2s
  4. physics

    What is the moment of inertia for a solid cylinder?
  5. physics

    A uniform horizontal beam with a length of 8m and a weight of 200N is attached to a wall by a pin connection. Its far end is supported by a cable that makes an angle of 53° with the beam (Figure below). If a 600N person stands 2m from the wall, ?nd the tension in the cable...
  6. physics

    A uniform ladder of length L rests against a smooth, vertical wall as shown in the figure below. If the mass of the ladder is m and the coefficient of static friction between the ladder and the ground is muks=0.4, ?nd the minimum angle theta at which the ladder does not slip.
  7. physics

    3)A baseball player holds a 36oz bat (weight = 10N) with one hand at the point O (Figure below). The bat is in equilibrium. The weight of the bat acts along a line 60cm (or 0.6m) to the right of O. Determine the force and torque exerted on the bat by the player.
  8. physics

    An electric motor exerts a constant torque of 10N?m to the shaft of a grindstone with mass 16kg and radius 0.5m. If the system starts from rest, find (a) the rotational kinetic energy of the grindstone after 8s, (b) the work done by the motor during this time, and (c) the ...
  9. physics

    is that right?
  10. physics

    TanTheta=tan^-1=W/H
  11. physics

    The uniform block of width W and height H in the figure below rests on an inclined plane in static equilibrium. The plane is slowly raised until the block begins to tip over. Assume the tipping occurs before the block starts to slide. Find an expression for the angle ? at ...
  12. physics

    How do I calculate String mass density from what I got frequency= 30.0Hz, segment length= 42.5cm , nodes=2, string length=83.5cm and tension=2.150kN?
  13. physics

    How do I calculate density of a string with what I have? The string mass is 12g and length is305.4cm
  14. Algebra

    Find ?(f??g)(x) and ?(g??f)(x). f(x)=4x(squared)+3?; ?g(x)=4x?2(f??g)(x)=______(Simplify your? answer.) I keep getting lost on these f(x) and g(x)problems
  15. Algebra

    This is the question word for word on MyMathLab. The title of the chapter it is from is "Problem Solving and Quadratic Functions"
  16. Algebra

    A company has determined that when x hundred dulcimers are? built, the average cost per dulcimer can be estimated by ?C(x)=0.2x(squared)?2.6x+9.950?, where? C(x) is in hundreds of dollars. What is the minimum average cost per dulcimer and how many dulcimers should be built to ...
  17. physics

    A solid cylinder of mass m and radius R rolls down a parabolic path PQR from height without slipping (assume R ? H) as shown in the figure below. Path PQ is rough (and so the cylinder will roll on that path), whereas path QR is smooth, or frictionless (so the cylinder will ...
  18. physics

    At one point during its swing, a wrecking ball exerts a tension force of FT = 9825 N on its cable, which makes an angle of ? = 25.0° with the horizontal. The crane's 9.00-m-long boom is at an angle of ? = 60.0° with the horizontal. What is the torque exerted by the...
  19. physics

    A wheel starts from rest and in 10.65 s is rotating with an angular speed of 5.810 ? rad/s. (a) Find the magnitude of the constant angular acceleration of the wheel. rad/s^2 (b) Through what angle does the wheel move in 6.085 s? rad
  20. physics

    A water molecule, consisting of two hydrogen atoms and one oxygen atom, resides in the plane of an x-y coordinate system. The coordinates of the oxygen atom and the two hydrogen atoms are, respectively, (0 m, 4.22 ? 10^?11 m), (7.57 ? 10^?11 m, 1.01 ? 10^?10 m) and (?7.57 ? 10...
  21. physics

    A ballistic pendulum is used to measure the speed of bullets. It comprises a heavy block of wood of mass M suspended by two long cords. A bullet of mass m is fired into the block in the horizontal direction. The block, with the bullet embedded in it, swings upward (see figure ...
  22. physics

    A helicopter rescues a trapped person of mass m = 67.0 kg from a flooded river by lifting the person vertically upward using a winch and rope. The person is pulled 13.0 m into the helicopter with a constant force that is 11% greater than the person's weight. (a) Find the ...
  23. figure description

    The figure is a rectangle on an xy plane. Line 1(red) starts from the origin (0,0) and goes right on the x-axis until it reaches the end of the rectangle, then it goes up until it reach the end of the rectangle and stop there. Line 2(blue) also starts from the origin but it ...
  24. physics

    Please help. If you need the figure, let know how I can show you and I will do it. A particle moves in the xy plane (see the figure below) from the origin to a point having coordinates x = 7.00 m and y = 4.00 m under the influence of a force given by F = 4y^2i? 2xj. (a) What ...
  25. physics

    A 1.80-g hailstone, which can be modeled as a particle, falls a vertical distance of 155 m at constant speed. What is the work done on the hailstone by gravity and air resistance? (a) gravity J (b) air resistance J
  26. physics

    A constant force of magnitude 5.75 N is exerted on an object. The force's direction is 57.5° counterclockwise from the positive x axis in the xy plane, and the object's displacement is ?r = (4.8i ? 2.2j + 1.7k) m. Calculate the work done by this force. J
  27. physics

    our answer isn't even close to the answer key. Have other idea?
  28. physics

    A newly established colony on the Moon launches a capsule vertically with an initial speed of 1.453 km/s. Ignoring the rotation of the Moon, what is the maximum height reached by the capsule? km The answer key is 1040km. I have tried v^2/2g (1.4532km/s)^2/(2*.0162km/s^2) and ...
  29. physics

    A newly established colony on the Moon launches a capsule vertically with an initial speed of 1.453 km/s. Ignoring the rotation of the Moon, what is the maximum height reached by the cap
  30. physics

    In each situation shown in the figure below, a ball moves from point A to point B. Use the following data to find the change in the gravitational potential energy in each case. You can assume that the radius of the ball is negligible. (a) h = 1.45 m, ? = 25°, and m = 0.80 ...
  31. physics

    A 0.410-kg soccer ball is kicked at an initial speed of 32.5 m/s at an angle of 33.0° to the horizontal. What is the kinetic energy of the soccer ball when it has reached the apex of its trajectory?
  32. physics

    more step please
  33. physics

    If ? = 40°, ? = 60°, and M = 4.0 kg, determine the tension in string 1 & 2. -------/ / 1 /2 / . . . Blockmass Alpha is on the top left angle and Beta is on the top right angle.
  34. physics

    The period of oscillation of a near-Earth satellite (neglecting atmospheric effects) is 84.3 min. What is the period of a near-Moon satellite? (R?= 6.37 × 10^6 m; RMoon= 1.74 × 10^6 m; m? = 5.98 × 10^24 kg; mMoon = 7.36 × 10^22 kg.)
  35. physics/math

    can somebody explain how 5.06(g-a)-4.24(g+a) become 0.82 g - 9.3 a I'm confused
  36. physic

    I don't get it can you do it in number form?
  37. physic

    where did 0.62g come from?
  38. physic

    How 5.06(g-a)become 0.82 g and 4.24(g+a)become 9.3
  39. physic

    where did you get 0.2g from?
  40. physic

    you are so coolDamon
  41. physic

    This the rightlink //d2vlcm61l7u1fs.cloudfront. net/media%2Ff38%2Ff385e045-5c9f-4f53-8ded-aa29a4d1d55c%2FphpOMgUlO.png
  42. physic

    //d2vlcm61l7u1fs.cloudfront. net/media%2Ff38%2Ff385e045-5c9f-4f53-8ded-aa29a4d1d55c%2FphpOMgUlO.png
  43. physic

    Find the acceleration of the block of mass M = 5.06 kg in the figure below. (Take m = 4.24 kg.)
  44. Physics

    The figure below shows a box of dirty money (mass m1 = 4.0 kg) on a frictionless plane inclined at angle ?1 = 35°. The box is connected via a cord of negligible mass to a box of laundered money (mass m2 = 2.0 kg) on a frictionless plane inclined at angle ?2 = 55°. The ...
  45. physic

    love you dr. neutron. your step are so easy to learn physic.
  46. physic

    The figure below shows a box of dirty money (mass m1 = 4.0 kg) on a frictionless plane inclined at angle ?1 = 35°. The box is connected via a cord of negligible mass to a box of laundered money (mass m2 = 2.0 kg) on a frictionless plane inclined at angle ?2 = 55°. The ...
  47. physic

    A 2.26 kg object is subjected to three forces that give it an acceleration a= ?(8m/s^2)i + (6m/s^2)j. If two of the three forces are F1 = (36.2 N)i + (18N)j and F2 = ?(12N)i + (8N)j,find the third force.
  48. physic

    Given that Earth orbits the Sun with a semimajor axis of 1.000 AU and an approximate orbital period of 365.24 days, determine the mass of the Sun. (1 AU = 1.496 ? 1011 m)
  49. physics

    Find the acceleration of the two blocks sliding down the incline in the figure below. (Take m1 = 1.1 kg and m2 = 1.8 kg. Indicate the direction with the sign of your answer Link to figure, copy and paste part by part Part1: //d2vlcm61l7u1fs.cloudfront. Part2: net/media%2Fda5%...
  50. physics

    Given that Earth orbits the Sun with a semimajor axis of 1.000 AU and an approximate orbital period of 365.24 days, determine the mass of the Sun. (1 AU = 1.496 ? 1011 m)
  51. physics

    In the figure below, 5.2 kg block A and 6.2 kg block B are connected by a string of negligible mass. Force A = (16 N) acts on block A; force B = (27 N) acts on block B. What is the tension in the string? (Express your answer in vector form.) To see the figure copy and paste ...
  52. physics

    Bobpursley,it look like you know what it wrong with my calculation. Can you show me in number--step by step to the answer key. I am not really get it with just word.
  53. physics

    disregard the parenthesis error. It was a typo.The mass of the sun from google is 1.989*10^30kgwhich is heavier than the earth mass of 5.972*10^24kg. The answer should be in year not second. Is there other idea to solve for this question? Please show ste to the answer key.
  54. physics

    Somebody please shows me step by step to the answer key for part b. I got stuck at it for days The answer key is .126yr but my answer is .687yr. It looks easy but it is not. This what I have done-->I plug in the values that I find on google into the equation.==> T^2=((...
  55. physics

    A race car travels 40 m/s around a banked (45° with the horizontal) circular (radius = 0.20 km) track. What is the magnitude of the resultant force on the 80-kg driver of this car?
  56. AP-B Physics

    a bug on a turntable which is rotating at 2.00 radians over second sits there for 1.7 seconds before he is brushed away. What was the angular distance the bug traveled.
  57. physic

    The Moon orbits Earth in a nearly circular orbit that lasts 27.32 days. Determine the distance from the surface of the Moon to the surface of Earth.
  58. physic

    i still don't know what the value for a is.I look up on google and it is the distance in AU and this question doesn't give what is the value for a.
  59. physic

    do you know what is a equal to. I know everything else except for a.
  60. physic

    Can somebody shows me step by step with numbers on how to calculate the period for this question-equation. A black hole is an object with mass, but no spatial extent. It truly is a particle. A black hole may form from a dead star. Such a black hole has a mass several times the...
  61. physics

    is there any way I can send you the picture?
  62. physics

    Find the acceleration of the two blocks sliding down the incline in the figure below. (Take m1 = 1.1 kg and m2 = 1.8 kg. Indicate the direction with the sign of your answer
  63. physic

    Somebody please show me how to get to the answer key for this question.I have been stuck at this question for days. Two black holes (the remains of exploded stars), separated by a distance of 10.0 AU(1 AU = 1.50 ? 10^11 m), attract one another with a gravitational force of 7....
  64. physics

    Two banked curves have the same radius. Curve A is banked at an angle of 12°, and curve B is banked at an angle of 20°. A car can travel around curve A without relying on friction at a speed of 19.5 m/s. At what speed can this car travel around curve B without relying ...
  65. physics

    thank you so much for helping I really appreciate it because I don't know how to do any of my study guide questions. I don't want just the answer but how you do it to study for a test. My teacher doesn't explain any thing. I wish I could just post all the questions...
  66. physics

    A skydiver of mass 81.5 kg (including outfit and equipment) floats downward suspended from her parachute, having reached terminal speed. The drag coefficient is 0.533, and the area of her parachute is 20.96 m^2 . The density of air is 1.14 kg/m^3 . What is the air's drag ...
  67. MATH

    can you explain how to use the quadratic solver stie? the value for b an dc are too large. It give me DNE when I enter them as you show above
  68. physics

    A mass m1 = 28 kg on a frictionless ramp is attached to a light string. The string passes over a frictionless pulley and is attached to a hanging mass m2. The ramp is at an angle of ? = 31° above the horizontal. m1 moves up the ramp uniformly (at constant speed). Find the...
  69. physic

    Two black holes (the remains of exploded stars), separated by a distance of 10.0 AU (1 AU = 1.50 ? 10^11 m), attract one another with a gravitational force of 6.50 ? 10^25 N. The combined mass of the two black holes is 5.40 ? 10^30 kg. What is the mass of each black hole? ...
  70. physic

    Two spheres of mass M1 = 810 kg and M2 = 390 kg are placed 4.80 m apart. A particle of mass m = 12.0 kg is now placed midway between the two spheres. (a) What is the net gravitational force on the particle due to the two spheres? N toward the sphere of M1 or M2 (b) At what ...
  71. physics

    Can somebody shows me how to get to the answer key? The answer for a) is 1.5, b) rP is 1.34AU and rA is 2.01AU and c) is .335AU Copy and past this link part by part as it is to see the figure: part1: webassign. part2: net part3: /katzpse1/7-p-009.gif Question: The figure below...
  72. physics

    If you want to see the figure, then type the website below part by part because jiskha doesn't allow the whole link be posted on it site. part1:world wide web part2: webassign. part2: net part:3: /katzpse1/ part4: 7-p-009.gif
  73. physics

    I know answer for a) is 1.5
  74. physics

    The figure below is a scaled representation of a planet's orbit with a semimajor axis of 1.528 AU. (Use the exact values you enter in previous answer(s) to make later calculation(s).) (a) Find the ratio of the aphelion-to-perihelion distance. rA rP = (b) Find the ...
  75. physic

    I don't understand this question at all. If you want to see the figure, let me know The figure below is a scaled representation of a planet's orbit with a semimajor axis of 1.528 AU. (Use the exact values you enter in previous answer(s) to make later calculation(s).) (...
  76. physic

    Does anybody know how I can find the mass of the electron for this question. I need to find it first to solve for the real one but don't see mass anywhere in the question.I see radiant and speed but no mass The radius of circular electron orbits in the Bohr model of the ...
  77. physics

    A black hole is an object with mass, but no spatial extent. It truly is a particle. A black hole may form from a dead star. Such a black hole has a mass several times the mass of the Sun. Imagine a black hole whose mass is eighty-two times the mass of the Sun. (a) Would you ...
  78. physics

    Consider the Earth and the Moon as a two-particle system. (a) Find the gravitational field of this two-particle system at the point that is exactly halfway between the Earth and the Moon. (Assume a radial direction r? from the Earth to the Moon. Express your answer in vector ...
  79. physics

    The radius of circular electron orbits in the Bohr model of the hydrogen atom are given by (5.29 ? 10^?11 m)n^2, where n is the electron's energy level (see figure below). The speed of the electron in each energy level is (c/137n), where c = 3 ? 10^8 m/s is the speed of ...
  80. physics

    A box of mass m rests on a rough, horizontal surface with a coefficient of static friction ?s. If a force Fp arrow is applied to the box at an angle ? as shown, what is the minimum value of ? for which the box will not move regardless of the magnitude of Fp? (Use any variable ...
  81. physics

    A small sphere of mass m = 0.520 kg is dropped from rest into a viscous liquid in which the resistive force on the sphere can be expressed as FD = ?bv, and reaches one-fourth of its terminal speed in 3.14 s. (a) What is the terminal speed of the sphere? m/s (b) What is the ...
  82. for steve

    Steve how does √((1.342t^2)^2 + (6.040t)^2) = 12.0 t = 1.839 I don't get it can you explain further? I took the square root of (1.342t^2)^2+(6.040t)^2 and it gives me 6.19
  83. physics

    what don't get it. ecan you explain more on the part ?((1.342t^2)^2 + (6.040t)^2) = 12.0 t = 1.839 ?
  84. physics

    can somebody shows me how to get to the answer key step by step. the answer key is 2.78i-10.2j A 1.49-kg particle initially at rest and at the origin of an x-y coordinate system is subjected to a time-dependent force of F(t) = (4.00ti ? 9.00j) N with t in seconds.What is the ...
  85. physics

    A sled and rider have a total mass of 58.4 kg. They are on a snowy hill accelerating at 0.4g. The coefficient of kinetic friction between the sled and the snow is 0.17. What is the angle of the hill's slope measured upward from the horizontal? You may find a spreadsheet ...
  86. physics

    A sled and rider have a total mass of 58.4 kg. They are on a snowy hill accelerating at 0.4g. The coefficient of kinetic friction between the sled and the snow is 0.17. What is the angle of the hill's slope measured upward from the horizontal? You may find a spreadsheet ...
  87. physics

    Somebody please shows me how to solve for b) and c)step by step. I found a)=2.27s but stuck there. A 1.49-kg particle initially at rest and at the origin of an x-y coordinate system is subjected to a time-dependent force of F(t) = (4.00ti ? 8.00j) Nwith t in seconds.(a) At ...
  88. physics

    I think you post your question at the wrong place. click on post a question on the top right so you can post your question for tutor to see and help you out.
  89. physics

    The radius of circular electron orbits in the Bohr model of the hydrogen atom are given by (5.29 ? 10?11 m)n2, where n is the electron's energy level (see figure below). The speed of the electron in each energy level is (c/137n), where c = 3 ? 108 m/s is the speed of light...
  90. physics

    The radius of circular electron orbits in the Bohr model of the hydrogen atom are given by (5.29 ? 10?11 m)n2, where n is the electron's energy level (see figure below). The speed of the electron in each energy level is (c/137n), where c = 3 ? 108 m/s is the speed of light...
  91. physics

    A box of mass m rests on a rough, horizontal surface with a coefficient of static friction ?s. If a force F with arrowp is applied to the box at an angle ? as shown, what is the minimum value of ? for which the box will not move regardless of the magnitude of F with arrowp? (...
  92. physics I need serious help please

    A 1.49-kg particle initially at rest and at the origin of an x-y coordinate system is subjected to a time-dependent force of F(t) = (4.00ti ? 8.00j) N with t in seconds. (a) At what time t will the particle's speed be 14.0 m/s? s (b) How far from the origin will the ...
  93. physic

    A force of 75.0 N in the horizontal direction is required to set a 37.3-kg box, initially at rest on a flat surface, in motion. After the box begins to move, a horizontal force of 51.3 N is required to maintain a constant speed. (a) What is the coefficient of static friction ...
  94. physic

    ehh Steve your method doesn't get me anywhere closer to the answer key. Cau you explain futher with steps?
  95. physic

    A 1.57-kg particle initially at rest and at the origin of an x-y coordinate system is subjected to a time-dependent force of F(t) = (7.00ti ? 8.00j)N with t in seconds. (a) At what time t will the particle's speed be 19.0 m/s? s (b) How far from the origin will the ...
  96. physics

    Harry Potter decides to take Pottery 101 as an elective to satisfy his arts requirement at Hogwarts. He sets some clay (m = 4.00 kg) on the edge of a pottery wheel (r = 0.730 m), which is initially motionless. He then begins to rotate the wheel with a uniform acceleration, ...
  97. physics

    Harry Potter decides to take Pottery 101 as an elective to satisfy his arts requirement at Hogwarts. He sets some clay (m = 4.00 kg) on the edge of a pottery wheel (r = 0.730 m), which is initially motionless. He then begins to rotate the wheel with a uniform acceleration, ...
  98. physics

    A sled and rider have a total mass of 57.2 kg. They are on a snowy hill accelerating at 0.5g. The coefficient of kinetic friction between the sled and the snow is 0.20. What is the angle of the hill's slope measured upward from the horizontal? You may find a spreadsheet ...
  99. physics

    can somebody shows me how to get to the answer key-- a)=2.51s, b)=19.9m, and c)=11.8i-16.1j A 1.57-kg particle initially at rest and at the origin of an x-y coordinate system is subjected to a time-dependent force of F(t) = (7.00ti ? 8.00j)N with t in seconds. (a) At what time...
  100. physics

    A 1.49-kg particle initially at rest and at the origin of an x-y coordinate system is subjected to a time-dependent force of F(t) = (4.00ti ? 8.00j) N with t in seconds. (a) At what time t will the particle's speed be 14.0 m/s? s (b) How far from the origin will the ...
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