physics please HELP !

74,851 results, page 87
  1. Physics

    A sample of charcoal from an archaeological site contains 55 g of carbon and decays at a rate of .877 Bq. How old is it? ok I am totally lost, I don't know where to start
  2. physics

    TWO LOCOMOTIVES APPROACH EACH OTHER ON PARALLEL TRACKS. EACH HAS A SPEED OF 95KM/H WITH RESPECT TO THE GROUNG. IF THEY ARE INITIALLY 8.5KM APART, HOW LONG WILL IT BE BEFORE THEY REACH EACH OTHER?
  3. physics urgent please

    Give an example of projectile motion;include in your explantion the term "velocity" , "accleration" and "displacement", orginality in your example will be appreciated?
  4. physics

    what is the magnitude of the centripetal force acting on the earth as it orbits the sun assuming a circular orbital speed of 3.00 X 10^4 meters per second
  5. physics

    If a pull of 350 N accelerates a 38-kg child on ice skates at a rate of 7.3 \frac{m}{s^2}, what is the frictional force acting on the skate?
  6. science(physics)

    give an example of projectile motion;include in your explantion the term velocity , accleration and displacement orginality in your example will be appreciated?
  7. Physics

    Calculate the height through which a crane can lift a load of 4 ton when it's motor of 4 H.P operates for 10 sec. Acceleration due to gravity is 10 m/s2
  8. Physics

    a 35 kg child slides down a 26 degree incline. the coefficient of kinetic friction is 0.33. what is her speed after sliding for 2.5 seconds starting from rest?
  9. Physics

    An outfielder throws a baseball to home plate with a velocity of +15 m/s and an angle of 30°. When will the ball reach its highest altitude? (Points : 3) 1.2 s 1.5 s 0.77 s 0.50 s
  10. Physics

    A crate with mass 26.0kg initially at rest on a warehouse floor is acted on by a net horizontal force of 160N .
  11. Physics

    Calculate the vertical distance an object dropped from rest would cover in 12s if it fell freely without air resistance.
  12. Physics

    Two people pushing a stalled car from rest generate a net force of +840N for 5.0s. What is the cars final velocity?
  13. physics

    CALCULATE THE ACCELERATION FOR A 10.0 KG BLOCK WHICH IS BEING PULLED UP A 35.0 DEGREE SLOPE BY A FORCE OF 140 N IF THE COEFFICIENT OF SLIDING FRICTION IS 0.100
  14. physics

    A stone of mass 2.8kg is projected upward with a speed of 5m/s. calculate the maximum height reached. use g=10m/s square.
  15. Physics

    A 172 N sign is supported in a motionless position by two ropes that each make an angle of 36° with the horizontal. What force does each rope exert?
  16. Physics

    A plane has an airspeed of 200 m/s due north and is subject to a westerly wind of 50 m/s. What is the planes speed relative to the ground?
  17. physics

    How much force does an 71 {\rm kg} astronaut exert on his chair while sitting at rest on the launch pad? Express your answer using two significant figures.
  18. physics

    A 25000 kg rock is located at a distance of 7.6 x 108 m away from a small planet of mass 7.8 x 1023 kg. What is the mutual force of attraction between these two
  19. Physics

    Suppose the surface (radius = r) of the space station in the figure is rotating at 38.6 m/s. What must be the value of r for the astronauts to weigh one-half of their earth-weight?
  20. physics

    calculate the net charge on a substance consisting of a combination of 2.6e13 protons and 6.0e13 electrons. answer in units of C.
  21. physics

    Two sinusoidal waves of the same frequency travel in the same direction along a string. If ym1 = 4.2 cm, ym2 = 5.9 cm, ö1 = 0, and ö2 = /5 rad, what is the amplitude (in cm) of the resultant wave?
  22. physics

    a toaster draws a current of 13.0A and has an electric potential difference of 120.V. For how long must it remain on to use 2.0x10^5J of electrical energy?
  23. Physics

    A car whose brakes are locked skids to a stop in 200 ft from an initial velocity of 50 mi/hr. Find the coefficient of sliding friction.
  24. physics

    a motorisrt accelerates their car to 36m/s before realising they are over the speed limit and decelerates to 32m/s. calculate the distance traveled
  25. physics

    a person whos mass is 102 kg stands on a beam supported by two ropes , A and B, he is standing on one foot to help you solve this problem.
  26. Physics- Lenses

    A planoconvex lens is to have a focal length of 28.5 cm. If made from fused quartz, what must be the radius of curvature of the convex surface?
  27. physics

    How much work in eV is required to bring three charges of 6.8x10-18C from a great distance apart to 5.04x10-9m from one another (at the corners of an equilateral triangle)?
  28. Physics

    A light-rail commuter train blows its 200 Hz horn as it approaches a crossing. The speed of sound is 332 m/s.
  29. physics

    A glacier advances at 4.3 × 10−6 cm/s.How far will it move in 6.4 years? Assume there is 365 days each year. Answer in units of cm. Thanks in advance!!
  30. physics

    if a cyclist takes one minute to comple half revolution on a circular path 120 m radius.what is the average velocity?
  31. Physics

    What is the magnitude of the electric field at a point midway between a −8.3μC and a +5.4μC charge 10cm apart? Assume no other charges are nearby.
  32. PHYSICS

    A grinding wheel 0.3m in diametre has amass of 5kg is rotating at an angular velocity of 2300rev/min.what is the kinetic energy?
  33. PHYSICS

    A grinding wheel 0.3m in diametre has amass of 5kg is rotating at an angular velocity of 2300rev/min.what is the kinetic energy?
  34. physics

    Determine the moment of inertia for three children weighing 57.0 lb, 42.0 lb and 78 lb sitting at different points on the edge of a rotating merry-go-round, which has a radius of 12 ft.
  35. physics

    In one mole or 18 grams of water, the total negative charge of all the electrons is: a. zero because its electrically neutral. b. less than one C c. almost 100,000 C. d. almost one million C. e. none of these
  36. physics

    A robot arm expends 15J of work to extend a spring 10cm from its equilibrium position. How much force is required?
  37. Physics

    Suppose the surface (radius = r) of the space station in the figure is rotating at 38.6 m/s. What must be the value of r for the astronauts to weigh one-half of their earth-weight?
  38. physics

    Calculate the gauge pressure inside a soap bubble 0.0002m in radius using the surface tension for soapy water
  39. Physics!!!

    How much work W must be done on a particle with a mass of m to accelerate it from rest to a speed of 0.899c ? Express your answer as a multiple of mc^2 to three significant figures.
  40. Physics

    the potential energy of a particle varies with velocity v as U equals to Av3/v + B where A and B are constant dimensional formula A/B is (1) ML-1T (2) M-1LT (3) L-1T-1 (4) MLT-1
  41. physics

    a string of cross section 2 cm^2 is doubled in length by the application of a longitudinal force 2*10^5dynes.the young"s modulus is: 1.10^5 dyne/cm^2
  42. physics

    The speed of sound in air is about 330m/sec. If a lighting flash occurs 5.5 seconds before you hear the thunder how far away from you was the strike?
  43. physics

    Two wires run parallel to each other with currents I1 = -60.3 A, and I2 = 44.1 A. If they are a = 0.12 m apart, what is the magnitude of the force (N) per meter of length? I used the formula (f/L)=Uo(I1)(I2)/(2(pi)(r)) I got 4.43810^-2(N/m)but it was
  44. Physics

    A player kicks a football from ground level with a velocity of magnitude 31.0 m/s at an angle of 30.0 degrees above the horizontal. What is its maximum height?
  45. Maths/Physics

    Is it possible to share a four fingered Kit Kat equally between 5 people if you can only break any one piece in half? Prove whether it is possible or impossible.
  46. physics

    Use these magnitudes of the forces of gravity at Earth's surface to determine the masses of the objects on which they act A)0.98N. B)62N C)44.5MN
  47. physics

    Time() 0 2 4 6 8 10 12 14 16 Velocity() 0 0 2 5 10 15 20 22 22 By measuring the slope of your curve, find the magnitude of the instantaneous acceleration at times = 9s i don't know how to solve it
  48. Physics

    A baseball with a mass of 0.145 kg is thrown straight down at the ground. At a particular speed, it has a drag force of 0.4 N acting on it. What is its acceleration at that time? a. -7.0 m/s2 b. -2.8 m/s2 c. -9.8 m/s2 d. -12.6 m/s2
  49. physics

    A satellite orbits at an average altitude of h = 423 km. How long does it need to complete one full orbit? Use REarth = 6370 km and mEarth = 5.98 x 10^24 kg
  50. physics

    Imagine having an 80-turn coil with radius of 5.0 cm and resistance of 30 Ù. At what rate must a perpendicular magnetic field change to produce a current of 4.0 A?
  51. physics

    find the equilibrium of two is N forces acting upon a body,when the angle betweenthem is a)90degrees b)120degrees c)180degrees d)10degrees e)45degrees
  52. General Physics 2

    three charges, +2.5×10^-6, -4.8×10^-6, and -6.3×10^-6, are located at (-20m,0.15m), (0.50m,-0.35m), and (-0.42m,-0.32m) respectively. What is the electric field at the origin?
  53. 11th grade physics

    the horizontal range of a projectile is 4 root 3 times of its maximum height. calculate the angle of projection.
  54. 11th grade physics

    if action and reaction are always equal and opposite, why don't they always cancel each other and leave no force for acceleration of the body?
  55. physics

    Use these magnitudes of the forces of gravity at Earth's surface to determine the masses of the objects on which they act A)0.98N. B)62N C)44.5MN
  56. Physics

    I am driving to Atlanta on the I-85 in my G35 Coupe at 40.0 m/s and I pass a cop. Will I get a ticket? The speed limit is 70.0 mi/h, 1 mile= 1.609 km = 1609 m.
  57. physics

    How much work in eV is required to bring three charges of 5.4x10-19C from a great distance apart to 3.76x10-8m from one another (at the corners of an equilateral triangle)?
  58. physics

    Two comets, each of mass 6500 kg and traveling 88 m/s in opposite directions, collide head-on and come to rest. How much energy is produced in this collision?
  59. PHYSICS

    How much work did the movers do (horizontally) pushing a 140-kg crate 10.1 m across a rough floor without acceleration, if the effective coefficient of friction was 0.60?
  60. physics

    When 1.60 multiplied by 105 J of heat enters a cherry pie initially at 20.0°C, its entropy increases by 470 J/K. What is its final temperature (C)?
  61. Physics

    How much work did the movers do (horizontally) pushing a 140-kg crate 10.1 m across a rough floor without acceleration, if the effective coefficient of friction was 0.60?
  62. Physics

    Carbon dioxide forms into a solid (dry ice) at approximately -157°F. What temperature in degrees Celsius does this correspond to?
  63. Intergated chemistry/physics

    What is the momentum of a 100 kilogram football player moving with a speed of 3.5 meters/second. The units should be written as kg m/s.
  64. physics

    brakes are applied in bringing in a 1200-kg car moving at 25 m/s to rest in 20.0 s. show that the amount of braking force is 1500n.
  65. physics

    Hm0 dug b00b pass taik pay 0ff.blue medcare x x1234567.sead h0sp
  66. Physics

    When a compact disk with a 12.0-cm diameter is rotating at 4.2 rad/s, what is (a) the linear speed and (b) the centripetal acceleration of a point on its outer rim?
  67. physics

    Two forces are applied to a car in an effort to move it, as shown in the following figure, where F1 = 416 N and F2 = 363 N. (Assume up and to the right as positive directions.)
  68. Physics

    two small spheres lie 1.5 meters apart and carry identical charges. How large is the charge on each if a sphere experiences a force of 2.0 N.
  69. Physics

    A 92 kg disk, with a radius of 0.97 meters, is rotating at 562 rpm. What is its angular momentum, to the nearest tenth of a Joule*sec?
  70. Physics

    A girl is floating in a freshwater lake with her head just above the water. If she weighs 395 N, what is the volume of the submerged part of her body?
  71. physics

    from point A, a boy walks 4 m to the east,2 m to the sout, 4 m to the west , and finally, 2 m to the north , find the distance he travelled and his displacement
  72. physics

    a framed painting weighs 220 newtons. the 2 wires support an angle of 120 degrees with each other. what are the tensions on the wire?
  73. Physics

    charges of -6nC and 4nC are 3m apart.(a)Determine the force they exert on each other.(b) the net electric field intensity at a point midway between them.
  74. Physics

    You drop a rock from a 300-meter cliff. How long will it take to reach the ground? Assume it has no significant air resistance
  75. physics

    A particular jet aircraft must reach a speed of 43 m/s in order to take-off. If the acceleration of the plane is 1329 m/s2, the minimum length of the runway is Answermeters
  76. Physics Need help plz

    An 1900 kg car is traveling with a speed of (22 +- .22) m/s. With what maximum accuracy can its position be determined? delta x= in meters Can someone please help me out I am lost on this on...Thank you
  77. physics

    Two identical balls A and B are released from the positions .They collide elastically on horizontal position MN. The ratio of the heights attained by A and B after collision will be ?
  78. Physics

    An austronaut orbits the Earth in the space shuttle, in one complete orbit, is the magnitude of thr displacement the same as the distance traveled?
  79. explian why please its physics

    expliain y the very high specific heat capacity of water leads to formation of land and sea breezes???
  80. physics

    When 1.60 multiplied by 105 J of heat enters a cherry pie initially at 20.0°C, its entropy increases by 470 J/K. What is its final temperature?
  81. physics

    How fast a Ford Focus car weighing 1200 kg should be moving to have the same momentum as the bullet? Express your answer in miles/hr.
  82. physics

    What average force is needed to accelerate a 6.00-gram pellet from rest to 110 over a distance of 0.800 along the barrel of a rifle?
  83. Physics

    A rocket blasts off with acceleration of 5 m/s squared. After 1 min it runs out of fuel. What is the max height and total time in the air?
  84. physics(optics)

    The critical angle between an equilateral prism and air is 45 degrees.if the incident ray is perpendicular to the refracting surface,then what happens?
  85. physics

    Four 6.0 kg spheres are located at the corners of a square of side 0.70 m. Calculate the magnitude and direction of the gravitational force on one sphere due to the other three.
  86. Physics

    A car slows down uniformly from a speed of 29.0 m/s to rest in 8.00s. How far does it travel in that time. - - I know that the equation is X = X0 + V0(t) + .5(at^2) I cant remeber where to put what numbers though. Thanks for the help!
  87. physics

    water 20 degrees celsius flows through a 25 mm diameter pipe at a rate of 50 liters per minute. is this laminar or turbulant flow or both?
  88. Physics

    a particle moving with a acceleration travels 24m and 64m in the first two consecutive intervals of 4 seconds each.find its initial velocity
  89. physics

    When 1.60 multiplied by 105 J of heat enters a cherry pie initially at 20.0°C, its entropy increases by 470 J/K. What is its final temperature (C)?
  90. physics

    A pump slowly lifts 3.0*10^6 kg of water an average distance of 80.0m in 12minutes. 1) how much work is done in the first 12 minutes? 2)How much power is delivered by the pumps?
  91. Physics

    3 particles of masses m1 = 1.5 kg , m2 = 2.5 kg and m3 = 3.5 kg form an equilateral triangle of edge length l= 135 cm. Determine the center of mass of the system.
  92. Physics

    A stone thrown upward to just reach the top of a palm tree that is 8.2m tall. Calculate the initial speed that is require
  93. physics

    A young boy swings a yo-yo horizontally above his head so that the yo-yo has a centripetal acceleration of 275 m/s2. If the yo-yo's string is 0.55 m long, what is the yo-yo's tangential speed?
  94. physics

    A 600 kg car is moving on a level road at 30 m/s. How large of a braking force is needed to stop it in a distance of 75m?
  95. Physics

    Suppose the surface (radius = r) of the space station in the figure is rotating at 38.6 m/s. What must be the value of r for the astronauts to weigh one-half of their earth-weight?
  96. Physics

    Starting from rest, a skier slides 100 m down a 28 degree slope.How much longer does the run take if the coefficient of kinetic friction is 0.17 instead of 0?
  97. PHYSICS

    An object is projected horizontally on a floor at 100ft/s. It then decceledates at 10ft/s2. After 5sec what are a.the speed of the body b. The distance it traversed
  98. physics

    mass = 46 kg, angle 20 degrees, tension 240 newton , coefficient of kinetic friction = 0.5 find acceleration of the object
  99. physics

    In a gas two waves of length 1m and 1.10m have a frequency difference of 10/3 Hz, the velocity of sound is ? a) 166m/s b) 332m/s c) 83m/s d) 336.7m/s
  100. Physics

    What is the net force acting on the ring in the diagram?