physics please HELP !

74,851 results, page 91
  1. Physics

    Rotating initially at 1800 rpm, a wheel with a diameter of 74.0 cm is brought to rest in 11.0 s. Calculate the magnitude of its angular acceleration in radians/second^2
  2. Physics

    A rocket moves upward, starting from rest with an acceleration of 35.0 m/s2 for 5.63 s. It runs out of fuel at the end of the 5.63 s but does not stop. How high does it rise above the ground?
  3. physics

    With an average acceleration of −1.6 m/s^2, how long will it take a cyclist to bring a bicycle with an initial speed of 13.3 m/s to a complete stop? Answer in units of s
  4. physics

    Driving home from school one day, you spot a ball rolling out into the street (see the figure ). You brake for 1.00 , slowing your 970- car from 16.0 to 9.50 .
  5. physics

    a car accelerates uniformly from rest to a speed of 21.8 km/h in 5.9 seconds.find the distance it travels during this time. answer in units of meters
  6. physics

    A Martian rover is moving up a hill sloped at 30.0° with the horizontal. If it has a constant velocity of 1.50 meters/second, calculate its vertical displacement after 21.0 seconds
  7. Physics

    A rocket moves upward, starting from rest with an acceleration of 35.0 m/s2 for 5.63 s. It runs out of fuel at the end of the 5.63 s but does not stop. How high does it rise above the ground?
  8. physics

    A 1-kg mass hangs by a string from a disk with radius 4.6 cm which has a rotational inertia of 5 × 10-5 kg·m2. After it falls a distance of 0.8 meters, how fast is it going to the nearest hundredth of a m/s?
  9. Physics

    A rocket moves upward, starting from rest with an acceleration of 35.0 m/s2 for 5.63 s. It runs out of fuel at the end of the 5.63 s but does not stop. How high does it rise above the ground?
  10. physics

    two perfect elastic balls of same mass m are moving with velocities u1 and u2 . they collide elastically n times. the kinetic energy of the system finally is?
  11. Physics

    Calculate the tension in the string if a single pulley of velocity ratio 5 is used to raise a body of mass 200g through a distance of 4cm.
  12. physics

    which of the following properties of a sound wave determines its pitch: wavelength, speed, amplitude, or frequency? Plese show work, Thank you, Silly
  13. Physics

    If the path-length difference between two identical and coherent beams is two wavelengths when they arrive on a screen, will they produce a dark or a bright spot?
  14. physics

    If a burning log is a black object with a surface area of 0.35 m2 and a temperature of 800 ˚C, how much power does it emit as thermal radiation?
  15. physics

    A punter kicks a football with a certain initial velocity of 13.8 m/s at an angle of 20.0o above the horizontal. How long does it take the ball to rise to the highest point of its tragetory?
  16. physics

    A diver jumps off a diving board with a speed of 25m/s he returns to the water after 3s. At the top of his dive describe his velocity and his acceleration?
  17. Physics

    An object is dropped from a platform 100 feet high. Ignoring wind resistance, what will its speed be when it reaches the ground? _____ ft/s Please help me!!!
  18. physics

    Find the velocity v and position r as functions of t for a particle of mass m which starts from rest at x=0 at time t=0 and subject to the following forces: F=Fo F=Fo +bti F=Fo coswt F=kt^2
  19. Physics!

    Suppose that you are standing on a train accelerating at 0.39g. What minimum coefficient of static friction must exist between your feet and the floor if you are not to slide?
  20. physics

    Two railroad cars, each of mass 1800 kg and traveling 70.0 km/hr, collide head-on and come to rest. How much thermal energy in joules is produced in this collision?
  21. Physics

    A 69 kg skier speeds down a trail, as shown in the figure. The surface is smooth and inclined at an angle of θ = 17° with the horizontal. Help me with an equation to solve. thanks!
  22. physics

    A rocket moves upward, starting from rest with an acceleration of 28.1 m/s2 for 4.76 s. It runs out of fuel at the end of the 4.76 s but does not stop. How high does it rise above the ground?
  23. Physics

    Use the first law of thermodynamics to determine the amount of heat change, Q, and whther it was added to or removd from the system. W=225J Delta U=600J Q=?
  24. physics

    What is the self-inductance of an air-core solenoid,1m long and 0.05m in diameter,if it has 1400 turns?(a)5.23mH(b)4.84mH(c)3.63mH(d)2.42mH
  25. Physics

    What is the angular momentum of a 2.4 kg uniform cylindrical grinding wheel of radius 12 cm when rotating at 1800 rpm? How much torque is required to stop it in 4.0 s?
  26. Physics

    STATE whether you expect the following entities to be in thermal equilibrium with their surroundings under normal circumstances. A. A desk - I think yes B. A person- I think yes C. The walls of a room- I think yes D. The sun- I think no
  27. physics

    an experimental jetplane just after takeoff climbs with a speed of 500km/hr at an angle of 37 degrees with the horizontal. At what rate is the plane gaining altitude?
  28. Physics

    A bullet fired into a fixed target loses half of its initial velocity in penetrating 15cm. How much further it will penetrate before coming to rest?
  29. Physics

    Steve can paddle his canoe at 10 km/h in still water. If he paddles directly against a river’s current that is moving at 3 km/h, what is Sam’s velocity relative to the shoreline?
  30. Physics HELP

    Two blocks of masses m1 = 6 kg and m2 = 6 kg are on either side of the wedge shown in the figure above. Find their acceleration and the tension in the rope. Ignore friction and the pulley.
  31. Physics

    A 52kg ice hockey player moving at 11m/s slows down and stops over a displacement os 8.0m. Calculate the net force of the skater.
  32. physics

    If a freely falling rock were equipped with a speedometer, by how much would its speed readings increase with each second IF it were on a planet where g = 20 m/s2? Show all work leading to your answer.
  33. physics (urgent)

    A flywheel with a moment of inertia of 1.00kg m^2 is rotating at 100 rpm. What torque is required to bring it to rest in 10.0 revolutions?
  34. Physics to Elena

    Ex=0 ; Ez=0 Ey = 10   sin(3.14x - 6.08e8 t) what is the time-averaged Poynting vector (magnitude and direction) for the position x=y=z=−3 ?
  35. Physics

    An arrow of mass 1000kg was fired from rest with a velocity of 15m/secs for a period of 0.5secs.calculate the applied force.
  36. physics

    A rocket moves upward, starting from rest with an acceleration of 29.4 m/s2 for 5.65 s. It runs out of fuel at the end of the 5.65 s but does not stop. How high does it rise above the ground?
  37. Physics

    Determine the stopping distance for a skier moving down a slope with friction with an initial speed of 20.6m/s. Assume μk=0.178 and θ=5.27.
  38. physics

    Two eagles fly directly toward one another, the first at 15.0 m/s and the second at 23.0 m/s. Both screech, one emitting a frequency of 2600 Hz and the other one of 3800 Hz. What frequencies do they receive if the speed of sound is 330 m/s?
  39. Physics

    A television tube operates at 20,000V. What is min wavelength for the continuous x-ray spectrum produced when the electrons hit the phosphor?
  40. physics

    With an average acceleration of −0.96 m/s2, how long will it take a cyclist to bring a bicycle with an initial speed of 14.8 m/s to a complete stop? Answer in units of s
  41. Physics with Calc

    A point charge of 1.8uC (microcoulumbs) is at the center of a Gaussian cube 55 cm on edge. What is the net electric flux through the surface?
  42. physics

    Suppose you wish to make a solenoid whose self-inductance is 3.0 mH. The inductor is to have a cross-sectional area of 2.0*10^-3 m2 and a length of 0.052 m. How many turns of wire are needed?
  43. physics

    why does the flame of a candle always faces upwards though the gravity of earth is pulling everything towards it centre? and though it is faced sidewards?please answer this question as quickly as possible
  44. physics multiple choice MCQ 5- i need help please @all respective sir & bro

    The unit of time in S.I. units is? a. second b. minute c. hour d. day e. year
  45. physics

    four resistor of resistances 1ohm,2ohm,3ohm,5ohm, are connected in series and afterwards in parallel.calculate the combined resistance in each case
  46. College Physics

    At what voltage would a 9 μF capacitor have the energy to lift 3 grams by 1 cm? i understand i need the0.5CV^2 equation however I don't know how to answer this
  47. Physics

    You drive your car 2 km to the gas station, 4 km to the shopping mall to let your mother off, and 4.5 km back home. The trip takes 20 min. What is your velocity in m/s?
  48. Physics

    A construction crane's cable lifts a 59.5-kg box upward with an acceleration of 1.38 m/s^2. Find the tension in the rope. 501.585 is incorrect.
  49. physics

    A sphere is fired downwards into a medium with an initial speed of 40 . Part A If it experiences a deceleration of , where is in seconds, determine the distance traveled before it stops.
  50. Physics

    A 600kg car is moving on a level road at 30m/s.how large is a retarding force is required to stop it in a distance of 70m
  51. physics

    At what projection angle will the range of a projectile equal to 6 times its maximum height? I know its easy but ive been absent and missed class!
  52. physics

    A body of mass 300g movers in a circle of 4m at a uniform speed of 12m/s. Calculate the angular velocity and the tripetal force
  53. Quantum Physics

    Suppose a particle has wavefunction ψ(x,t=0)=Aexp(−x22l2). What is the average value (expectation value) of p^, ⟨p^⟩, for this state at t=0?
  54. physics

    A power line 10 meter high carries a current 200 amperes .Find the magnetic field of the wire at ground?
  55. physics

    A typical color television draws about 2.8 A when connected to a 145 V source. What is the effective resistance of the T.V. set? Answer in units of Ω.
  56. Physics

    A bicyclist climbs a hill 17 m tall and then coasts down the other side without pedaling. If the cyclist’s speed was 2.5 m/s at the top, what is it at the bottom (ignoring friction)?
  57. Physics

    What is the threshold frequency for the photoelectric effect on lithium (phi= 2.93eV)? What is the stopping potential if the wavelength of the incident light is 400nm?
  58. Physics

    Ahmad throws a ball straight up. For which situation is the vertical velocity zero? [Note: Neglect the air resistance] Answer at the top on the way up none of the above on the way down
  59. physics

    A 2 kg metal plate slides down a 14-meter high slope. At the bottom its speed is 11.1 m/s. To the nearest Joule, what was the magnitude of the work done by friction?
  60. physics

    an astronaut is competing in mars olympic game her mass is 50 kg she will drive from tower 17 mm above a pool of water how much work in nj must she do to climb 17m
  61. Physics

    During a football game, A is 8.0 m behind B and is running at 7.0 m/s when B catches the ball and starts to accelerate away at 2.8 m/s(squared) from rest. a) Will A catch B? If so, after how long? b) How far down the field will B have run?
  62. math,physics,chemisty,biology

    the number of moles of H2O2 required to completely react with 400ml of 0.5N KMnO4 in acidic medium are
  63. physics

    Two eagles fly directly toward one another, the first at 15.0 m/s and the second at 21.0 m/s. Both screech, one emitting a frequency of 3200 Hz and the other one of 3800 Hz. What frequencies do they receive if the speed of sound is 330 m/s?
  64. Physics

    A 200-Ù resistor, 40.0-mH inductor and a 2.00-ìF capacitor are connected in series with a 120-V rms source at 1000 Hz. What is the phase angle of this circuit?
  65. Integrated Physics and Chemistry

    Some refrigerants used in air conditioners have been associated with.. A)somg B)destruction of the ozone layer C)thermal pollution D)power failures
  66. physics

    A pendulum has a mass of 3-kg, a length of 1.3 meter, and swings through a (half) arc of 30 degrees. To the tenth of a Joule, what is its maximum Kinetic Energy?
  67. Physics

    A bullet is fired straight up from a gun with a muzzle velocity of 312 m/s. Neglecting air resistance, what will be its displacement after 1.4 s? The acceleration of gravity is 9.8 m/s 2 .
  68. Physics

    What will be the average braking force needed to bring a car of mass 800kg traveling 72km/hr to a stop at a distance of 100m
  69. physics

    The longest pass in NFL history is approximately 83.7 m. Ignoring the effects of air resistance, calculate what must have been the initial speed of the football.
  70. Physics

    A television tube operates at 20,000V. What is min wavelength for the continuous x-ray spectrum produced when the electrons hit the phosphor?
  71. Physics

    What is the threshold frequency for the photoelectric effect on lithium (phi= 2.93eV)? What is the stopping potential if the wavelength of the incident light is 400nm?
  72. physics

    a diver dives from the top of a 100m cliff. he begins his dive by jumping up with a velocity of 5m/s how long does it takes for him to hit the water below?
  73. physics

    a mass of 0.1kg falls freely under the action of gravity .find the force acting on it its momentum kinetic energy after 10s?
  74. physics

    You're explaining to a younggster at the seashore why the water is cyan colored.The youngster points to the whitecaps of overturning waves and ask why they are white. what is your answer?
  75. physics

    Add the following vectors 1.50m{North 45 degrees West}, 10m{South30degreesEast}, 25Meters[South60mWest] pls help. explain to me how to solve it
  76. physics

    Two eagles fly directly toward one another, the first at 15.0 m/s and the second at 21.0 m/s. Both screech, one emitting a frequency of 3200 Hz and the other one of 3800 Hz. What frequencies do they receive if the speed of sound is 330 m/s?
  77. Physics

    Three balls A, B and C are kept in a straight line. The separation between A and C is 1 m, and B is placed at the midpoint between them. The masses of A, B, C are 100 g, 200 g and 300 g respectively. Find the net gravitational force on (a) A, (b) B, and
  78. Physics

    A rocket moves upward, starting from rest with an acceleration of 26.3 m/s2 for 5.43 s. It runs out of fuel at the end of the 5.43 s but does not stop. How high does it rise above the ground?
  79. Physics

    A 0.55 kg block slides across a tabletop with initial velocity of 3 m/s and it comes to rest in a distance of 0.53 m. Find the average friction force that retarded its motion.
  80. physics

    A stone is thrown downward into a well with an initial speed of 5.00 m/s. The sound of splash is heard 1.50 s later. Find the depth of the well if the air temperature is 15.0 ˚C?
  81. Physics

    Three point charges are on the x axis: −9 μC at −3 m, 2 μC at the origin, and −5 μC at 3m. Find the force on the first charge. The value of the Coulomb constant is 8.98755 × 109 N · m2/C2. Answer in units of N.
  82. physics

    Three balls A, B and C are kept in a straight line. The separation between A and C is 1 m, and B is placed at the midpoint between them. The masses of A, B, C are 100 g, 200 g and 300 g respectively. Find the net gravitational force on (a) A, (b) B, and
  83. physics

    Two eagles fly directly toward one another, the first at 15.0 m/s and the second at 21.0 m/s. Both screech, one emitting a frequency of 3200 Hz and the other one of 3800 Hz. What frequencies do they receive if the speed of sound is 330 m/s?
  84. Physics

    A jack has a lever arm of 45cm and pitch of 0.5cm. If it's efficiency is 30%,what force is required to lift a load W of mass 1200kg
  85. physics

    using a sketchs, show the type of directions of forces acting on the following farm hand tools i) a hoe ii) a rake for land clearing 0
  86. physics

    Bob is riding his bike along at 2m/s and drops his 2kg backpack from a height of 1.5 meters. What is the backpacks resulting velocity when it strikes the ground?
  87. physics

    What is the magnitude of the electrostatic force that the two protons inside the nucleus of a helium atom exert on each other? Why do atomic nuclei not simply explode?
  88. physics

    3 stings are attached on a ring. 2 of the strings make 70 degrees angle and each is pulled with 7.0 N . What force must be applied to keep the 3rd string to keep stationary?
  89. physics

    (a) What linear speed must an Earth satellite have to be in a circular orbit at an altitude of 153 km? m/s (b) What is the period of revolution? min Read the eBook
  90. Physics

    Two concentric conducing spheres of radii 4 cm and 12 cm are given equal but opposite charges of 6 x 10^-8C. How much energy is stored in the system? How would I go about in beginning to solve this problem?
  91. physics

    Consider a particle initially moving with a velocity of 5m/s starts deaccelarating at a constant rate of 2m/s*2 find the distance travelled in 2sec? Ans:2m
  92. Science - Physics

    Some helium at 20.0psi gauge pressure occupies 40.0ft^3. find its volume at 32.4 psi if the temperature remains constant.
  93. Physics

    I need to explain and demonstrate mathematically why it is easier to pull a wheelbarrow than it is to push it. Also, what effect does the component of force parallel to a bicycle crank have?
  94. physics

    You are on a hike in the mountains. You have 4.92 km left to go before your next campsite. The sun will set in 6.6 h. What avergae speed must you walk to camp at sunset? Answer in units of km/h
  95. physics

    if you wished to warm 100 kg of water by 15 degrees celsius for your bath, how much heat would be required? (give your answer in calories and joules)
  96. Physics

    A stone popelled from a catalpult with the speed of 50m/s attained a height of 100m. Calculate the time of flight and angle of projection.
  97. Physics

    A jet aircraft is accelerating at 4.3 m/s2 as it climbs at an angle of è = 44° above the horizontal (see figure). What is the total force that the cockpit seat exerts on the 77 kg pilot?
  98. Physics

    A bolt is to be tightened with a torque of 8.0 N*m. If you have a wrench that is 0.35 m long, what is the least amount of force you must exert? the equation for this problem is t=Fr sinbeta, but the sin is not given What am I suppose to do?
  99. Physics

    Calculate the pressure on the top lid of a chest buried under 4.30 meters of mud with density 1.75 103 kg/m3 at the bottom of a 12.5-m-deep lake
  100. Physics

    What is the greatest safe speed, without skidding, that a 1700 kg car can have on a level curve of radius 215 meters if Mk=0.4 and Ms=.85? Answer=42.3 I tried using the equation mv^2/r=mg+Mk.