physics please HELP !

74,760 results, page 82
  1. Physics

    Computer the power output in watt of a machine that lift a 50kg crete through a height of 20cm in 1minute
  2. Physics

    “Strontium-90 is a pure beta source.” How could a physicist test this statement? I am stuck on this one, but I was thinking through measurement of radioactivity.
  3. physics

    If a trapeze artist rotates once each second while sailing through the air and contracts to reduce her rotational inertia to one-third of what it was, how many rotations per second will result?
  4. Physics

    You throw a ball towards a wall at 15ms-1, and it bounces back at 10ms-1. What is the total change in velocity? (the answer is not 5m/s)
  5. Physics

    An object slides down a frictionless 33 degree incline whose vertical height is 54.0 cm. How fast is it going in meters/second when it reaches the bottom?
  6. Physics

    What gravitational force do yhe two protons in the helium nucleus exert on each other? There separation is approximately 1.0 fm. I know that 1 fm is 10^-15 m i didn't know if that was how you figured it out to get it to N?
  7. College Physics

    two charged particles are located on an x axis: -q = -4.80 × 10-19 C at x = -3.00 m and q = 4.80 × 10-19 C at x = 3.00 m. What are the (a)x- and (b)y- components of the net electric field produced at point P at y = 5.00 m?
  8. physics

    Determine the ionization energy required to extract the electron totally out of a hydrogen atom, and put it at rest
  9. physics

    what is the length of the shortest pipe closed on one end that will have a fundamental frequency of 60 hz on a day when the velocity of sound is 340 m/s?
  10. science (physics)

    A body travels 10m in 5th second and 30m in 10th second. Find its initial velocity and acceleration.
  11. Physics

    What is the minimum work in joules needed to push a 1460 kg car 14.0 m up a 12.5 degree incline? (Ignore friction.)
  12. physics

    Stand on a 200 meter high building and, at noon, drop a ball. At what time does it hit the ground
  13. Physics

    If a projectile is fired straight up at a speed of 10 m/s, the total time to return to its starting position is about ? When I use the quadratic formula, I get -8.97
  14. Physics

    Which object has a greater momentum, a stationary tractor-trailer or a tossed tennis ball? Explain your answer please.
  15. Physics

    At what distance should an object be placed in front of a convex lens of focal length 20 cm to obtain an image of double its size
  16. physics

    a man holds a child on his shoulders while watching a football match. How much work has he done if the game lasts for 2 hours
  17. physics

    An object glides on a horizontal tabletop with a coefficient of kinetic friction of 0.65. If it comes to rest after 0.9 seconds, what was its initial velocity?
  18. physics

    A piano wire has length L and mass M. If its fundamental frequency is f, its tension is: i got T=(lambda*f)^2m/L, but their answer is 4LMF^2 and i cant figure out how to get that
  19. Physics

    A floating ball normally weighs 7 N. The acceleration of gravity is 9.8 m/s^2. What is the size of the buoyant force that acts on it? Answer in units of N.
  20. Physics

    Two objects attract each other gravitionally with a force of 2.5 *10^-10 N when they are .25m apart. Their total mass is 4.0kg. Find their individual masses.
  21. Physics

    An object is thrown directly up (positive direction) with a velocity (vo) of 20.0 m/s and do= 0. Determine how long it takes to get to the maximum height of 24.0 m.
  22. Physics

    If a person jumped off the side of a ship from 20 feet high what speed would they be travelling at when they impact the water? Thanks Mike
  23. physics

    Jessica stretches her arms out 0.6 m from the center of her body while holding a 2 kg mass in each hand. She then spins around on an ice rink at 1.1 m/s.
  24. Physics

    A Ferris wheel has a radius of 14 m. What period of rotation would give the occupants a feeling of "weightlessness" at the top? __s
  25. physics

    You are driving north on a highway. Then, without changing speed, you round a curve and drive east. Does your velocity change?
  26. Physics

    Is the answer to this 4? If the filament resistance in an automobile headlamp is 3 ohms, how many amps does it draw when connected to a 12-volt battery?
  27. Physics

    What is the magnitude of buoyant force acting on a 720 cm^3 toy submarine floating in fresh water? (D_water =1 g/cm^3)
  28. physics

    a bar is pushed so that it slides across the floor. how far will it go, given the coefficient of kinetic friction is 0.25, and the push imparts an initial speed of 2.5m/s?
  29. Circuits/physics

    For the element shown below, v(t)=1/2tVolts and i(t) = 12t-4t^2 Amps. (a) Find the instantaneous power p(t) as a function of time. + v(t) - |------| -----| |----- |------| i(t)----->

    Give some examples of applications that resulted from work done by physicists? Radios, Televisions, CD's, Computers, etc. Is my answer correct?
  31. physics

    A rock is thrown upward at an angle of 50 degrees with respect to the horizon. As it rises, its vertical component of velocity does what?
  32. Physics

    A rocket blasts off. In 10.0 seconds it is at 10,000 ft, traveling at 3600 mph. Assuming the direction is up, calculate the acceleration.
  33. physics

    If You do 100 j of work to elevate a bucket of water,what is its gravitational potential energy relative to its starting position?
  34. physics

    i need help with this one! A 100KHz oscillator that's followed by a doubler and two triplers will produce an output of frequency.... a.) 180 kHz b.) 500 " c.) 800 " d.) 1.8 "
  35. physics

    How much time will it take a car travelling at 88 km/hr (55 mi/hr) to travel 500km? Show work for credit and include final units.
  36. Physics

    A 1200kg car accelreates from 0mph-60mph in 8.5 seconds. Calculate the force needed to accelerate the vehicle.
  37. physics

    Calculate the hang time of a person who moves horizontally 2.00 m during a 1.23 m high jump. Express your answer with the appropriate units

    What is the acceleration (in meters/second^2) of a freely falling 73.0 kg sky-diver, if air resistance exerts a force of 273 N?
  39. physics

    A particle of mass 10 kg is slowly lifted up to a height of 10 metre then calculate the workdone by external and gravity force ?
  40. physics

    How much thrust is required to launch a 5 kg bottle rocket with an upward acceleration of 6.4 m/s2? I've gotten 32 because F=MA but I don't understand how to account for gravity. Please help!
  41. physics for life sciences

    since action and reaction are exactly equal and oppositely directed how is it ever possible for a net force to be acting on a body?
  42. physics

    Peter Pan is suspended in space. He throws an entire jar of pixie dust to his left. Which way does he move?
  43. physics

    A loaded truck can accelerate at 6.4 m/s^2. It loses its load so that it is only 0.9 as massive. By what factor must the acceleration change for the same driving force?
  44. Physics

    A student travels 6.0 m [E] in 3.0 s and then 10.0 m [N] in 4.0 s. Draw a vector diagram to determine the resultant displacement. Q: How do you know where the starting point is on the graph?
  45. Career Planning

    What job opportunities are offered for a bachelors degree of joint honours in both physics and math besides teaching?
  46. Physics

    A construction worker exerts 209N to move a load of bricks a distance of 10m across the parking lot,
  47. physics

    A female gymnast weighs 200 N. If she is hanging stationary from a high bar,how many forces are acting on her? A. one B.five C.four D.two E.three WOuld it be choice A or D?

    The weight of a hollow sphere is 100N.If it floats in water just fully submerged,what is the exterrnal diameter of the shere ?
  49. physics

    A loaded truck can accelerate at 6.4 m/s^2. It loses its load so that it is only 0.9 as massive. By what factor must the acceleration change for the same driving force?
  50. Physics

    A car accelerates uniformly from rest to a speed of 23.9 km/h in 8.2 s. Find the distance it travels during this time. Answer in units of m
  51. physics

    two ropes are tied on a post and applied with forces of 8 and ion.If the amgle between them is 60degrees. Find the resultant vector
  52. physics relativity

    An observer on Earth sees you travel 1000 m at half the speed of light. What distance do you think that you travelled?
  53. Physics

    This problem is about the work-energy theorem. What is the final speed of the particle? Express your answer in terms of K_f and M.
  54. physics

    Calculate the kinetic energy acquired by a 11- nail when it is struck by a 540- hammer moving with an initial speed of 4.9 .
  55. physics

    A car traveling initially at 9.52 m/s acceler- ates at the rate of 0.609 m/s2 for 3.62 s. What is its velocity at the end of the accel- eration?
  56. physics

    starting from rest, find a 54.6kg child’s speed at the bottom of a 15.5m tall slide if it is assumed to be frictionless
  57. Physics

    Hello, I am wondering if someone can answer me this question: In an Atwood machine why do the tensions that handle both bodies are the same? (English is not my native language)
  58. physics

    A long jumper jumps at a 20 degree angle and attains a maximum altitude of .6 m. a)what is her initial speed? b)How far is her jump?
  59. AP Physics<<help

    A 1.7 kg bundle starts up a 30 degree inlcine with 105 J of Kinetic Eneergy, How far will it slide up in the plane if the coefficient of friction is .3 ?
  60. Physics

    a dense plastic toy mass of 1.2kg is floating just beneath the surface of a pond. What is the bouyant force?
  61. College Physics II

    If a capacitor has 3.84 μC of charge on it and an electric field of 2.22 kV/mm is desired if they are separated by 3.80 mm of air, what must each plate's area be?
  62. Physics

    Problem 3- If a bug can jump straight up to a height of 0.5 m. a) what is its initial speed as it leaves the ground? b) How long is it in the air?
  63. physics

    A shotputter accelerates a 7.3kg shot from rest to 14m/s. If this motion takes 2.0s what average power was developed?
  64. physics

    to view full image of an object 160 cm high, the minimum size of the plane mirror required is?
  65. physics

    what is the shortest possible time in which a bacterium could drift at a constant speed of 3.5mm/s across a petri dish with a diameter of 8.4cm
  66. Physics

    A 16-kg child sits on a 5-kg sled and slides down a 143-meter, 30-degree slope, to the nearest m/s what is his or her speed at the bottom?
  67. physics

    A car accelerates uniformly from rest to a speed of 21.2 km/h in 8.3 s. Find the distance it travels during this time. Answer in units of m
  68. Physics

    In relativistic regimes, the total energy of an object with rest mass, m, speed, v, is: a); (Gama)mc^2 B);squre root of (m^2c^4 + p^2c^2)
  69. Physics

    How much work (in J) must be done to lift a stack of bricks, which has a mass of 600 kg, from the ground to a height of 15 m? Acceleration due to gravity is 10 m/s2
  70. Physics

    A person weighing 900 Newtons is standing on snowshoes. Each snowshoe has an area of 2500cm^2. What is the pressure on the snow?
  71. physics

    a pitches takes 0.10 seconds to throw a baseball, which leaves his hand at a velocity of 30m/s. the balls acceleration is?
  72. Physics

    A 84.0-kg airplane pilot pulls out of a dive by following, at a constant speed of 163 km/h, the arc of a circle whose radius is 312.0 m.
  73. physics

    a pitches takes 0.10 seconds to throw a baseball, which leaves his hand at a velocity of 30m/s the ball's acceleration is?
  74. Physics

    Three particles have charges +20μC each.They are fixed at the corners of an equilateral triangle of side 0.5m .The force on each of particle has magnitude
  75. physics

    Races are timed to an accuracy of 1/1000 of a second. What distance could a person rollerblading at a speed of 8.5 m/s travel in that period of time?
  76. physics

    How much heat is absorbed by a 30g iron skillet when its temperature rises from 24oC to 93oC? Joules do i addition everything?
  77. Physics

    Two bowling balls each have a mass of 6.8kg. the speres are located nest to one another with their centers 21.8 cm apart. what gravitational force do they exert on each other?
  78. physics

    a toroid has 3000 turns. the inner and outer diameter are 22 cm and 26 cm. what is the flux density inside the core when there is a current of 5 amperes?
  79. college physics

    How fast (in rpm) must a centrifuge rotate if a particle 9.50 cm from the axis of rotation is to experience an acceleration of 113000 g's? Need help please.
  80. physics

    A loaded truck can accelerate at 8.8 m/s 2 . It loses its load so that it is only 0.6 as massive. By what factor must the acceleration change for the same driving force?
  81. Physics Help

    An electron with velocity v = 2.4 × 106 m/s i encounters an electric field E = 1250 N/C i. How long will it take for the speed to be one fourth its original value?
  82. physics

    If a cyclist traveling at 14.0m/s skids to a stop in 5.60 s, determine the skidding distance assume uniform acceleration? Answer is 39.2m
  83. Physics

    conical pendulum is formed by attaching a 0.200 ball to a 1.00 -long. It has a radius of 40.0cm . What is the tension in the string?
  84. physics

    Find the time it would have taken a horse to run: displacement: +1609 m average acceleration: +0.0105 m/s^2 initial velocity: +16.58 m/s
  85. Math Physics

    A wattmeter shows that a motor is drawing 2200w. What horsepower is being delivered? Is this correct? 2200/746 = 2.95
  86. Physics

    I just need ideas on how i can estimate the height of a building by using only a tennis ball and a stop watch. I can only measure it by being on the ground level.
  87. Physics for Life science

    1.Since action and reaction are exactly equal and oppositely directed, how is ever possible for a net force to be acting on the body?
  88. Physics

    A boy sledding down a hill accelerates at 1.24 m/s2 . If he started from rest, in what distance would he reach a speed of 8.88 m/s? Answer in units of m
  89. Physics

    An American bald eagle heads south at 5.5 m/s, but encounters a wind blowing from the east at 1.9 m/s. By how many degrees will she be blown o course?
  90. Physics

    A 3kg block is resting on a table with a coefficient of friction of 0.4. It is now pushed with a force of 15n. What is the acceleration of the book?
  91. physics

    A 78-kg parachutist, in the first few seconds of her jump, accelerates at a rate of 7.4 m/s2 [down]. Calculate the force she experiences due to air resistance.
  92. physics

    what r the 4 forces on a plane whilst in flight?, im confused, i don't no whether it means like air resistance....or thrust.maybe u cud help me out :S
  93. physics

    What is the acceleration (in meters/second^2) of a freely falling 74.0 kg sky-diver, if air resistance exerts a force of 264 N?
  94. Physics

    What is the minimum work in joules needed to push a 1840 kg car 14.0 m up a 12.5 degree incline? (Ignore friction.)
  95. Physics

    A hiker shouts towards a vertical cliff 465 m away. The echo is heard 2.75 s. later. The wavelength of the sound is 0.750 m. What is its frequency?
  96. physics

    an american bald eagle heads south at 3.2 m/s, but encounters a wind blowing from the east at.97 m/s by how many degrees will she be blown off course?
  97. Physics

    at what distance would a convex magnifing lens that has a focal length of 10 cm have to be held for an image to appear upright and 3 cm tall? [6.67cm]
  98. Physics

    A proton moving at 500000m/s enters a series of charged parallel plates. What is the impact speed on the last plate.
  99. Physics

    Explain why the mass of the vehicle does not affect the calculated maximum or minimum velocities for cars on banked curves.
  100. Physics

    A ball rolling down a hill was displaced at 19.6m while uniformly accelerating from rest. If the final velocity was 5.00 m/s what was the rate of acceptation?