physics please HELP !

74,641 results, page 99

  1. physics

    if you driving your car into a brick wall and are not wearing a seat belt, you will be badly injured why? your answer should include the word ''force'' and ''velocity''
  2. physics

    a 0.5KG ball is drop at concrete incline which is 45 degree above the horizontal then bounces off with the speed of 5m/s due to the force applied on it what is the change in its momentum?
  3. physics

    You drop a rock into a deep well and 4.1s later hear the splash. How far down is the water? Neglect the travel time of the sound. Express your answer using two significant figures.
  4. Physics

    A 10.4-g CD with a radius of 5.85 cm rotates with an angular speed of 33.8 rad/s. What is its kinetic energy? (in J) I need help with this question. I thought you would just use K=1/2mv^2 but when I use m=0.0104kg and v=33.8 I get 5.94 which isn't the correct answer....
  5. Physics

    A real spring does not oscillate forever. Instead, it eventually comes to a stop. Does this violate the Law of Conservation of Energy? Explain why or why not. I truly don't know what this means at all...can someone help me understand it?
  6. physics!!!

    For the vectors with a = 14, b = 13, and c = 365, calculate the following dot products. NOTE theres a picture but i couldn't upload its a right angle triangle with c as the hypt, a bottom and b side
  7. Physics

    A model airplane has a mass of .90 kg and moves at a constant speed on a circle that is parallel to the ground. Find the tension in the guideline (length = 17 m) for speeds of 19 and 38 m/s.
  8. Physics

    One type of aeroplane has a maximum acceleration on the ground of 3.4m/s what is the minimum length of runaway needed if it is to reach its take off speed of 110m/s.and how long atime will this take.
  9. physics

    Three positive point charges of q1 = 4.0 nC, q2 = 6.4 nC, and q3 = 1.5 nC, respectively, are arranged in a triangular pattern, as shown below. Find the magnitude and direction of the electric force acting on the 6.4 nC charge.
  10. Physics

    A gun shoots a bullet at 1200 m/s at an angle of 600 above the horizontal. Neglecting air resistance, determine: a.) its time of flight b.) its range
  11. Physics

    An outfielder throws a 2.12 kg baseball at a speed of 114 m/s and an initial angle of 54.8 ◦ . What is the kinetic energy of the ball at the highest point of its motion?
  12. physics

    An automobile tire is rated to last for 60,000 miles. To an order of magnitude, through how many revolutions will it turn? i put 10E7 but i got it wrong since i used 1rev/8ft
  13. physics

    To what temperature must you raise a copper wire, originally at 20.0°C, to double its resistance, neglecting any changes in dimensions? (Does this happen in household wiring under ordinary circumstances?)
  14. College Physics

    A child swings a yo-yo of weight mg in a horizontal circle so that the cord makes an angle of 30 degrees with the vertical. Find the centripetal acceleration.
  15. Physics

    3 equal charges each of of 2*10-6 C are fixed at three corners of an equilateral triangle ofsides 5 cm.find the column force experienced by one of the charge due to the rest two.
  16. Physics

    Two identical particles, each of mass 1400 kg, are coasting in free space along the same path. At one instant their separation is 30.0 m and each has precisely the same velocity of 820 m/s. What are their velocities when they are 4.00 m apart?
  17. physics

    State only Gauss law in integral form.Use it to find out electric field due to an isolated homogeneous sphere of charges at an outside point.
  18. Physics

    A racing car with mass (including the driver) of 900 kg accelerates from rest to a speed of 200 km/hr in 6 seconds. what is the power output of the engine?
  19. Physics

    Laser light of wavelength 632nm is incident on a diffraction grating having 600 lines per mm. Determine the angular separation between the first and second order maxima
  20. Physics - Grade 10

    Grant stands 3 meters from the check out at the grocery store holding a 20N bag of potatoes for 10 minutes. How much work does he perform?
  21. math/physics

    5. Consider a particle moving counter-clockwise around the ellipse x^9/9 +y^2/4 = 1. Find a relationship between dy/dt and dx/dt What are the rates of change of y and x at the times when the other variable isn't . changing at all?
  22. physics

    An electric train moving at 20kmh accelerates to a speed of 30kmh in 20 seconds.find the distance travelled in metres during the period of acceleration
  23. Physics

    A car moving at a constant speed of 50km/h turns a corner, changing it's direction from north to west. What is it's change in velocity. What was the acceleration if the then took 5s

    Scientists call a theory that unites many ideas in a simple way "beautiful." Are unity and simplicity among the criteria of beauty outside of science? Support your answer
  25. physics

    Express the following measurements as indicated. A. 6.20 mg in kilograms B. 3X10^-9 s in milliseconds C. 88.0 km in meters A. 6.20mg (1g/1000mg)(1kg/1000g) You do the rest. I will be happy to critique your work.
  26. physics

    According to newtons 1st law , construction workers are warned not to leave their hard hats on the rear window ledge of their cars, explain why?
  27. Physics

    suppose that two point charges each with a charge of +1 coulomb are separated by a distance of 1 meter will they attract or repel ? determine the magnitude of the electrical force between them
  28. physics

    To what temperature must you raise a copper wire, originally at 20.0°C, to double its resistance, neglecting any changes in dimensions? (Does this happen in household wiring under ordinary circumstances?)
  29. physics

    a ball of mass 0.4 kg is initially at rest on the ground. It is kicked and leaves the kicker's foot with a speed of 5 m/s in a direction of 60 degrees above the horizontal. What is the impulse
  30. Physics

    A golf ball is driven, by Emilee, horizontally from an elevated tee with a velocity of 90.65 km/hr. It strikes the fairway 6.34 sec later. How far has it fallen vertically? and how did u find it please
  31. Physics

    A man pulls a 10-kg box across a smooth floor with a force of 71 newtons at an angle of 23 degrees and for a distance of 97 meters. How much work, to the nearest joule, does he do?
  32. physics

    Each charge of 3 micro coulomb are placed at 3 corners of a square whose diagonal is 6cm long. Find the field intensity at the point of intersection of diagonals
  33. physics

    Young's modulus for a rod is 4 X 4x10 to the 11th power. what strain will be produced by a tensile stress of 420 MPa? I don't know where to start with this...
  34. physics

    12.5 kg wooden crate with an initial velocity of 2.5 m/s slides across a rough cement floor for 1.7 m before coming to rest. Calculate the coefficient of kinetic friction
  35. Physics

    A skier traveling 12.0 m/s reaches the foot of a steady upward 18° incline and glides 18.2 m up along this slope before coming to rest. What was the average coefficient of friction?
  36. physics

    a gun can shell targets 15 km away. find (a)the min launch speed needed to achieve that range (b) the shells flight time under these conditions
  37. Physics

    suppose that two point charges each with a charge of +1 coulomb are separated by a distance of 1 meter will they attract or repel ? determine the magnitude of the electrical force between them

    Calculate the stress, strain and young's modulus of a wire with a cross-sectional area of 3 x 10^-7 m^2 and a length of 0.6 m that is stretched to a distance of 1.2 x 10^-3 by a 120 N force.
  39. physics

    I'm not sure how to solve this..a baseball is popped straight up into the air and has a hang-time of 6.25s. Determine the height to which the ball rises before it reaches its peak.
  40. physics

    two boys start running straight toward each other from two points that are 100m apart,one runs with a speed of 5m/s while the other moves at 7m/ close are they to the slower one's starting point when they reach each other
  41. integrated physics and chemistry

    classes of steel and iron are defined by the amount of WHAT? and other elements present in the alloy. is it zinc,tin,carbon,or aluminum?
  42. Physics

    Calculate the electric force between these two electrons. The value of the Coulomb constant 9 × 109 N · m2/C2 and the elemental charge is 1.6×10−19C. Answer in units of N (Newtons)
  43. physics

    a 1240 kg automobile stops in a distance of 41m. if initial velocity was 22.5m/s, what force did the road exert on the car to stop it? Answer pls... Thank You
  44. Physics

    There is an 8 meter tall hill with a circular radius of 20 meters. What is yhe minimum speed a car needs to momentarily lose contact with the road?
  45. physics

    In a roller coaster ride cars and passengers slide down an incline of 36 degrees to horizontal if the friction is negligible find magnitude of acceleration
  46. Physics

    First start with an isothermal expansion at 2.0 atm from 1.0 L to 4.0 L. If this now is adiabatically compressed back to its original volume, what is the change in internal energy here? Also what are some examples of these processes?
  47. physics

    when 100 J of work is done on a stationary flywheel ( that is otherwise free to rotate in place), its angular speed increases from 60 rev/min. What is its moment of inertia?
  48. Physics

    If the force of friction is constant, prove that the stopping distance of a car on a level road varies directly with the square of the initial speed.
  49. physics

    A proton with charge mass ratio of 108 C/kg is moving in a circular orbit in a uniform magnetic field of 0.5T .Calculate the frequency of revolution.
  50. physics

    The speed of sound in air is 350m/sec the frequency of the fundamental node emitted by tube length 50cm open one end is:
  51. physics

    The earth's atmosphere extends to a height of nearby 200KM above its surface there many be explosion and noises taking place in the outer space but we do not hear them.why?
  52. Physics

    When a solar flare erupts on the surface of the sun, how many minutes after it occurs does its light show up in an astronomer's telescope on earth? I am totally!
  53. physics

    Two point charges of -86.5 mC and 36.3 mC are held fixed on an x axis at the origin and x = 24.4 cm, respectively. What are the magnitude and direction of the total electrostatic force on a third charge of 18.8 mC placed at (a) x = 48.8 cm (b) x = 97.6 cm I've tried everything...
  54. physics

    If a wire has a resistance of 132ohms a length of 110cm and an area of cross- sectional of 0.00415cm square find the resistivity of the material of which it is made
  55. physics

    ⦁ An arrow is shot with speed 36.0 m/s at an angle of 24.0° above the horizontal. Assuming the archer was on level ground, find the maximum height and the range.
  56. AP physics

    According to the equation a=bc what type of relationship (direct or inverse) exerts between the quantities A and C? Draw a qualitive graph to describe the relation between A and C. Assumeing B is constante.
  57. physics

    A 244 g particle is released from rest at point A inside a smooth hemispherical bowl of ra- dius 21.7 cm, as shown in the figure The acceleration of gravity if 9.81 m/s2 .

    Estimate the terminal speed of a wooden sphere (density 0.700 g/cm3) falling through air if its radius is 3.20 cm and its drag coefficient is 0.470.
  59. Physics

    The first leg of a relay race is semi circle of diameter 50m. If the runner covers the distance in 11s.calculate the average speed”
  60. Physics, still don't get it!

    Suppose a monatomic ideal gas is contained within a vertical cylinder that is fitted with a movable piston. The piston is frictionless and has a negligible mass. The area of the piston is 3.06 10-2 m2, and the pressure outside the cylinder is 1.02 105 Pa. Heat (2109 J) is ...
  61. physics - additional info added

    SEE ADDITIONAL INFO ADDED Using the motor principle explain why a motor is rotating in the direction indicated. I seriuosly have no idea, please help explain this theory to me. PHYSICS - drwls, Saturday, February 6, 2010 at 2:15pm To help you answer that question, I'd need a ...
  62. trig/physics

    Three positive particles of equal charge +11.o micro C, are located at the corners of an equilateral triangle of sides 15.0cm. Calculate magnitude and direction of the net force on each particle. DUUUUUUUUUH! THIS IS SO EASY! LOOK IN YOUR BOK, IDIOTIC DUDE! R U A BOY AND HOT, ...
  63. Physics

    A light string, connects blocks 1 and 2 of masses m1 and m2. These blocks are further connected to a block of mass M by another light string that passes over a pulley of negligible mass and friction. Blocks 1 and 2 move with a constant velocity v down the inclined plane, which...
  64. Probability

    The probability that a student passes a physics test is 2/3 and the probability that he passed both physics test and an english test is 14/15. The probability. The probability that he passes at least one test is 4/5. What is the probability that he passes the english test.
  65. Science, Physics, math, calculus

    Pool players often pride themselves on their ability to impart a large speed on a pool ball. In the sport of billiards, event organizers often remove one of the rails on a pool table to allow players to measure the speed of their break shots (the opening shot of a game in ...
  66. Physics (Center of Gravity)

    In a lab in my physics class, we were supposed to find the CG of my physics teacher. My partner and I had him lie flat on a wooden (assumed uniform) board that was resting on top of two PVC pipes at either end. Since the PVC pipes acted as the base of support, and since things...
  67. physics homework

    can you please check my answers? 10. when rewinding a an audio tape or vdieotape, one reel winds fastest at the end. which reel is this? why does it speed up? -The reel is the left and it speeds up because of its greater rotational intertia is near the rim. 15.the wheels of ...
  68. Physics

    Please help me with these three questions,they deal with coefficient of friction 1) A car rounds a turn of radius 25m at a speed of 20m/s. Find the coefficient of friction neccessary to keep the car on the road 2) A man is attempting to slide a piece of furniture weighing 750N...
  69. Physics

    Pool players often pride themselves on their ability to impart a large speed to a pool ball. In the sport of billiards, event organizers often remove one of the rails on a pool table to allow players to measure the speed of their break shots (the opening shot of a game in ...
  70. Physics

    Someone posted the question below, stating that they knew the answer to part A but needed help with part B. Well even with the answer for A, I can't figure it out! Can you take a step back from the question below to show me the steps for solving part A? I've been working on ...
  71. Physics

    ool players often pride themselves on their ability to impart a large speed to a pool ball. In the sport of billiards, event organizers often remove one of the rails on a pool table to allow players to measure the speed of their break shots (the opening shot of a game in which...
  72. Physics

    Hi. I am Walter White. I am good at chemistry but suck at physics. Can you help me? ---------------------------------------- Bob is traveling in a very fast space (v=0.8c) away from Alice, who is sitting still in an observatory watching him through a very good telescope. Bob ...
  73. PHYSICS!

    0.115 kg of water at 81.0o C is poured into an insulated cup containing 0.220 kg of ice initally at 0o. Calculate the mass of liquid when the system reaches thermal equilibrium.
  74. physics

    A 21.0-kg child descends a slide 2.20m high and reaches the bottom with a speed of 1.40m/s . How much thermal energy due to friction was generated in this process?
  75. Physics(astronomy)

    Radio waves and x-rays are similar in what: a) comparable wavelengths b) cannot compare c)have same photon energies On the test, it said those and I picked a. Is that correct? I am nervous T_T
  76. Physics

    an airplaine is flying at constant speed of 500 km/h on a straight line at 33000 feet above sea level. what is the net force acting on the airplane?
  77. Physics

    2. How much energy would a body of mass 50kg need to provide for the following: a. Climbing a hill 500m high. b. Walking up steps 10m tall. c. Jumping 10cm up.
  78. physics

    When landing after a spectacular somersault, a 40.0 kg gymnast decelerates by pushing straight down on the mat. Calculate the force she must exert if her deceleration is 5.00 times the acceleration of gravity.
  79. Physics

    A spiral spring 20cm long is stretched to 25cm by a load of 50N.What will be its length when streched by 100N assumimg that the elastic limit is not reached?
  80. physics

    An infinitely long wire carrying a current of 2 A is bent at a right angle as shown in the Figure. What is the magnetic field magnitude in Tesla a point P, 10 cm from the corner?
  81. physics

    The acceleration of gravity is 9.8 m/s 2 . What is the magnitude of the total force on a(n) 87 kg driver by the dragster he operates as it accelerates horizontally along a straight line from rest to 41 m/s in 5.3 s? Answer in units of kN
  82. Physics

    The acceleration of gravity is 9.8 m/s^2 . What is the magnitude of the total force on a(n) 72 kg driver by the dragster he operates as it accelerates horizontally along a straight line from rest to 61 m/s in 7.8 s? Answer in units of kN
  83. Physics

    Calculate the angular momentum and kinetic energy of a solid uniform sphere with a radius of 0.120 m and a mass of 14.0 kg if it is rotating at 6.00 rad/s about an axis through its center..
  84. physics

    Suppose David Ortiz hits a home run which travels 361. feet (110. m). Assuming it left the bat at 50.°, how fast was it hit?
  85. physics

    A bullet is fired straight up from a gun with a muzzle velocity of 225 m/s. Neglecting air resistance, what will be its displacement after 6.1 s? The acceleration of gravity is 9.8 m/s2 . Answer in units of m
  86. Physics

    Radio waves travel at the speed of light, which is 3.00 108 m/s. What is the wavelength for a FM station broadcasting at 105.9 MHz (the prefix M is "mega" and means 106)?
  87. Physics

    Two small spheres spaced 20.0 centimeters apart have equal charge. How many excess electrons must be present on each sphere if the magnitude of the force of repulsion between them is 4.57×10 −21 newtons?
  88. Physics

    A 80kg football player stands at the end of a uniform 8m, 50kg diving board supported as shown. Determine the forces exerted by the two supports.
  89. physics

    a uniform rectangular marble slab is 3.4m long and 2.0 m wide with a mass of 180kg. it is lyning on flat ground how much work is needed to stand it on end
  90. Physics

    The coefficient of static friction between hard rubber and normal street pavement is about 0.42. On how steep a hill (maximum angle) can you leave a car parked?
  91. physics please helpp

    Find the minimum diameter of a 51.5-m-long nylon string that will stretch no more than 1.01 cm when a load of 68.9 kg is suspended from its lower end. Assume that Ynylon = 3.51·108 N/m2
  92. Physics

    A spectrometer uses a grating with 11600 lines/cm. Find the angle at which red light, 632.3 nm, has the first-order bright band. Answer in units of degrees.
  93. Physics

    Jill and her friends have built a small rocket that soon after lift-off reaches a speed of 900 m/s How high above the Earth can it rise? Ignore air friction. h=? m
  94. physics

    A hippo has a mass of 6000kg. When standing on 4 feet, how much pressure is exerted on the ground? Assume each foot has an area of 0.10 square meter. Show your work.
  95. physics

    If we apply 300 kJ of heat to 2500 moles of air at constant pressure, what is the change in internal energy? Answer a. 214 kJ. b. 100 kJ. c. 180 kJ. d. 75 kJ.
  96. physics

    During a baseball game, a batter hits a popup to a fielder 80 m away. The acceleration of gravity is 9.8 m/s2 . If the ball remains in the air for 5.5 s, how high does it rise? Answer in units of m.
  97. physics

    A football is thrown upward at a(n) 23◦ angleto the horizontal. The acceleration of gravity is 9.8 m/s To throw a(n) 52 m pass, what must be the initial speed of the ball? Answer in units of m/s
  98. physics

    an arrow is shot into the air with an initial velocity of 100m is at elevation of 60 degree find. a the time of flight b the maximum height attained c the range
  99. Physics

    An engine of car of power 40KW moves on a rough road wit a velocity of force require to bring it to rest.
  100. Physics

    Calculate the following, expressing the answer in scientific notation with the correct number of significant figures: (8.86 + 1.0 * 10^-3) / 3.610 * 10^-3 please help me write out the equation and fill in the appropriate data thanks for your help Jiskha
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