physics please HELP !

74,851 results, page 58
  1. physics

    An elevator is moving upward at 1.20 m/s when it experiences an acceleration 0.25 m/s2 downward, over a distance of 0.71 m. What will its final velocity be?
  2. physics help!

    Using the Bohr model, estimate the wavelength ë of the Ká characteristic X-ray for a metal an atom of which contains Z = 50 protons.
  3. physics

    Using the Bohr model, estimate the wavelength ë of the Ká characteristic X-ray for a metal an atom of which contains Z = 50 protons.
  4. Physics

    In a hydrogen atom, if the radius of the orbit of the electron is doubled, then its energy will ... >> Increase by a factor of 2??
  5. physics

    George takes off for a long jump at an angle of 28 degrees, and lands 6.9 m away. How fast was he when he jumped?
  6. physics

    Radio waves transmitted through space at 3.00¡¿10 8 m/s by the Voyager spacecraft have a wavelength of 0.120 m. What is their frequency?
  7. physics

    If your boat weighs 1600 N, how much water will it displace when it’s floating motionless at the surface of a lake?
  8. Physics

    What net external force is required to give a 30 kg suitcase an acceleration of 2.5 m/s2 to the right? Answer in units of N
  9. physics

    What is the magnitude of F? Assume the acceleration due to gravity is 9.8 m/s 2 and the surface is frictionless. Answer in units of N.
  10. physics

    A rock is dropped from a height of 130.0 meters. With what velocity does it land? How long does it take to fall?
  11. Physics/ optics

    An object is located 25cm in front of a +6.00 lens, where is the image? is it real or virtual?
  12. Physics

    A boy sledding down a hill accelerates at 1.25 m/s2. If he started from rest, in what distance would he reach a speed of 5.00 m/s?
  13. college physics

    How many seconds would it take a 7.00hp motor to raise a 475 lb boiler to a platform 38.0 ft high?
  14. Physics

    An elevator is moving upward at 0.90 m/s when it experiences an acceleration 0.40 m/s2 downward, over a distance of 0.64 m. What will its final velocity be?
  15. physics

    For a simple 15 upward ramp, what length would be needed for a runaway truck traveling 140 ?
  16. Physics

    A boy sledding down a hill accelerates at 1.25 m/s2. If he started from rest, in what distance would he reach a speed of 5.00 m/s?
  17. college physics

    how long would it take a 4.50kW MOTOR TO RAISE A 175KG BOILER TO A PLATFORM 15.0M ABOVE THE FLOOR?
  18. AP Physics B

    What is the force of Friction as a 12 kg object slides down for 30 meters down a 30 degrees incline at a constant velocity?
  19. Physics

    a boat sails 150km N60°E, then 100km West. What is it's displacement from its starting point?
  20. Physics check

    Atoms whose nuclei have the same number of protons but different numbers of neutrons are called.... isotopes?
  21. mathematical method of physics

    expand 3sin(4x)+4cos(10x) in to functional series of e(exp)ix
  22. Physics

    A 2473 kg elephant is walking at 3 m/s on a flat surface. How much kinetic energy does he have? Answer in Joules or J
  23. physics

    How high will an object rise if it is projected upward at a 45 degree angle and an initial velocity of 50 m/s?
  24. Physics Please

    You want to show that V^2 - Vo^2 = 2 a (X - Xo) first rewrite that as: (V-Vo)(V+Vo) = 2a (X-Xo) now your average velocity during the interval = (V+Vo)/2 so X = Xo + t(V+Vo)/2 but V = Vo + a t so t = (V-Vo)/a so X = Xo +(V-Vo)(V+Vo)/2a we are there.
  25. Physics

    A 6.25 kg solid ball with a radius of 0.185 m rolls without slipping at 3.55 m/s. What is its total kinetic energy?
  26. Physics

    A 2473 kg elephant is walking at 3 m/s on a flat surface. How much kinetic energy does he have? Answer in Joules
  27. Physics

    If the fundamental frequency of an 70 cm long guitar string is 470 Hz, what is the speed of the traveling waves?
  28. Physics

    How could you use the spotlights at a play to make the yellow clothes of the performers suddenly change to black?
  29. physics

    a car is moving at 17.7 m/s when it begins to slow down with a deceleration of 2.5 m/s2. how long does it take to travel 20 meters as it slows down
  30. ap physics

    How fast would a 1200 kg car travel if it had the same linear momentum as a 1500 kg truck traveling at 90 km/h?
  31. physics

    find the change n momentum of a 1120-kg car that increases its speed / what minimum force is need to do this?
  32. Physics

    A skydiver has a terminal velocity of 9.0 m/s. If they have a mass of 98, what is their k value for their air resistance? Use g = 10 m/s/s and do not report units on your answer, they should be N s/m.
  33. physics

    WHAT IS THE REASON BEHIND THE JISKHA"S TEACHERS TO BE NOTHING!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!(except Writeacher and STEVE) ARE THEY DAFT OR NUISANCE!!!!!!!!!!!!!!!!!! ANSWWER Me QUICKLY !!!!!!!!!!!!!
  34. physics

    Describe how the energy from a rotating flywheel can be transferred to moving parts of a child's toy.
  35. Physics

    A spring has a a constant of 650 N/m. How far must it be compressed to push a 4kg object on a friction-less surface to 3 m/s?
  36. physics

    If your boat weighs 1400 N, how much water will it displace when it’s floating motionless at the surface of a lake?
  37. physics

    How high will an object rise if it is projected upward at a 45 degree angle and an initial velocity of 50 m/s?
  38. science physics

    i don't get how to solve this please help me Two resistors, 47 Ù and 82 Ù, are connected in series across a 45 V battery. What is the current in the circuit?
  39. Physics

    From the position vs time graph of an object moving with constant acceleration, how could you find the velocity
  40. Physics

    An elevator is moving upward at 0.97 m/s when it experiences an acceleration 0.34 m/s 2 downward, over a distance of 0.80 m. What will its final velocity be?
  41. physics

    how many revolutions per minute would a 15 m ferris wheel need to make for passengers to feel weightless at the top?
  42. physics

    Find the total force necessary to give a rocket of mass 25,000 slugs an acceleration of 28.0 ft/s2.
  43. Physics

    How long does it take T-Rex to reach its food 200m away assuming that he starts from rest and accelerates at 4.00 m/s2?
  44. 11th grade Physics

    What voltage is necessary to produce a current of 200 amperes through a resistance of 1 x 10^-3 ohms?
  45. 11th grade Physics

    What is the current produced by a 9-volt battery flowing through a resistance of 2 x 10^-4 ohms?
  46. Physics

    A motor cyclist travelling at 12m/s decelerate at 3m/s(squared)? How far does he travel while coming to rest?
  47. physics

    if a worker pushes a box 3 times as far as you do and exerts double the force you applied, which one of you does more work and by how much?
  48. math or physics

    Find the distance from 0 to 3 of the ∫ l3t-5ldt. I don't understand how the answer is 41/6.
  49. physics

    What is the magnitude and direction of an electric field that exerts a 4.00 ✕ 10 -5 N upward force on a - 1.80 µC charge? N/C
  50. physics

    A body immersed in liquid has an upthrust of 140N with a density of 12kg calculate the velocity
  51. Physics

    A loud speaker emits energy in all directions at a rate of 2.75 J/s . What is the intensity level at a distance of 25 m?
  52. Physics

    A train whose speed is 100km/hr rounds a curve whose radius of curvature is 150m what is the acceleration?
  53. Health Physics

    As one exhales, what change in energy takes place between the diaphragm and the air in the lungs?
  54. Physics

    A 200kg motorcycle is driving in a circular path at 1 rev per 5 seconds and the circle has r=12m
  55. physics

    How fast (in ) must a centrifuge rotate if a particle 8.00 from the axis of rotation is to experience an acceleration of 117000 's?
  56. Physics

    A solid weigh 45N and 15N respectively in air and water. Calculate the relative density
  57. physics

    Find the voltage increase when 12 J of work is done to push a 0.0013 C charge into an electric field.
  58. physics

    What is the number of the highest harmonic that could be heard by a person who is capable of hearing frequencies up to 1.00×104 ?
  59. Physics

    What will a spring scale read for the weight of a 75 kg woman in an elevator that moves upward with acceleration 0.30 g? w=?
  60. Physics

    What is the efficiency of a crane that used current of 8A at 150V to raise 450kg load at the rate of every minutes?
  61. physics

    A.Use newtons first law to explain why whiplash occurs? B.why are cars fitted with head rests?
  62. physics

    A 1.00 x 10^3 kg sports car accelerates from rest to 25.0 m/s in 7.50 s. What is the average power output of the automobile engine?
  63. Physics

    Calculate the length of a displaced pendulum Bob which pass through its lowest point twice every second. Take g=10m/s²
  64. physics

    A 8.2 kg object undergoes an acceleration of 2.5 m/s2. What is the magnitude of the resultant force acting on it? Answer in units of N
  65. Physics

    the speed of a train increases from 15 mi/h in a distance of 500 ft. calculate the average acceleration in ft/s squared
  66. physics

    Consider the motion of the tip of the minute hand of a clock. In one hour, the displacement and average velocity is .......
  67. Another physics question...

    Deduce the electric field strenght at a point midway between charges of 7.2*10^-6 C and -3.4*10^-6 C that are 2.0m apart from air. Thank you!
  68. physics

    How long will it take a 1030 W motor to lift a 330 kg piano to a sixth-story window 13.0 m above?
  69. physics

    Correct the following statement: The racing car rounds the turn at a constant velocity of 145 km/hr.
  70. physics

    what is the distance traveled by a vehicle in 12 minutes, if it's speed is 35km/h? And the answer I got was 7km but I got it wrong. Please help!
  71. Physics

    A positive and a negative charge, each of magnitude 1.0 10-5 C, are separated by a distance of 12 cm. Find the force on each of the particles
  72. physics

    A radio station is broadcasting at 90.7 mhz. compute for its wavelength in angstrom and energy in kilojoules.
  73. Physics

    what is the mass of hydrogen peroixide, H2O2, in 350 grams ofa 20% by weight solution?
  74. physics

    If you do 110 J of work to elevate a bucket of water, how much energy did you add to the gravitational field?
  75. physics

    Calculate the speed of sound wave in air if its frequencies and wavelengths are 256Hz and 1.32m
  76. physics

    A positive and a negative charge, each with a magnitude of 1.41 x 10^-5 C, are separated by a distance of 0.44 m. Find the force on each of the particles.
  77. physics

    A 1.56kg seagull dives through the air and gains 4495 of energy.What is the birds speed?
  78. Physics

    How much force is needed to bring a 3200 lb car from rest to a velocity of 44 ft/s in 8 seconds? Please indicate the formula used.
  79. Physics

    a child twirls a yo-yo about in a horizontal circle. The yo-yo has a mass of 0.20 kg and is attached to a string 0.8 m long. what is the velocity of the yo-yo? thanks!
  80. physics

    How much centripetal force is needed to keep a 0.20 kg ball on a 1.50 m string moving in a circular path with a speed of 3.0 m/s?
  81. physics

    Forces of 4.57 N and 4.74 N act at right angles on a reddish-green block of mass 5.76 kg. How much acceleration occurs?
  82. physics

    How much centripetal force is needed to keep a 0.20 kg ball on a 1.50 m string moving in a circular path with a speed of 3.0 m/s?
  83. physics

    How long will it take a 1280 W motor to lift a 345 kg piano to a sixth-story window 19.0 m above?
  84. Physics

    A 1300 kg sports car accelerates from rest to 85 km/h in 6.2 s. What is the average power delivered by the engine?
  85. physics

    An object is projected at an angle of elevation of 45 degree with a velocity of 100 m/s calculate its range
  86. physics

    A 0.49 cm high object is placed 8.5 cm in front of a diverging lens whose focal length is -7.5 cm. What is the height of the image?
  87. physics

    If you cover your home thermostat with a blanket, will it make the house hotter or colder, or have some other effect?
  88. physics

    at highway speeds, a particular automobile is capable of an acceleration of about 2.6 m/s^2. at this rate, how long does it take to accelerate from 60 km/h to 110 km/h?
  89. Physics

    an athlete executing a long jump leaving the ground at an angle of 30° and travels 8.9m .what was the take off speed?
  90. physics

    a car of mass(m)800kg initially at rest is accelerated at rate of 4m/s calculate the k.e @ 5seconds
  91. Physics

    Is this true or false? All objects moving in a circle are accelerated. I really don't uderstand this question.
  92. PHYSICS

    The force applied by the e-brake is F(eb) = m*a(eb) = -8.13*1452 = -12,100 N I didn't get the same answer - I got 11,804.76....please check
  93. Physics

    In general, what conditions with observable effects make magnets interact with non-magnet materials?
  94. Physics

    Calculate the distance (in km)that Larry runs if he maintains an average speed of 8km/hr for 45 minutes.
  95. 11th grade Physics

    What happens when a conductor is wired in parallel with the bulb? Is the swich open or closed?
  96. PHYSICS

    A pebble is tossed off a skyscraper and reaches the groung 7.65 seconds later. How tall is this building? 7.65 s x 9.8 m/s^2 = 74.97 meters????? Not sure if I did this right? Thanks
  97. Physics

    Two spherical objects with a mass of 7.60 kg each are placed at a distance of 2.93 m apart. How many electrons need to leave each object so that the net force between them becomes zero?
  98. physics

    Explain how an object can orbit a planet & why astronauts float around in the orbiting space shuttle
  99. Physics

    Why is the total distance traveled by a mass traveling in a circle of radius R during n revolutions, 2piRn?
  100. physics

    What frequency would you need to produce a sound wave in room-temperature air with a wavelength of 9 m? the answer in Hz