Login or Sign Up
Ask a New Question

Physics

  1. A person pushes a box. He applies a force of 400 newtons, and he pushes the box for a distance of 4 meters. After he stops pushing, the box slides forward another meter. How much work was done by the person?

    • 100 joules • 2,000 joules • 1,600 joules

  2. A racquet ball with mass m = 0.238 kg is moving toward the wall at v = 12.5 m/s and at an angle of θ = 31° with respect to the horizontal. The ball makes a perfectly elastic collision with the solid, frictionless wall and rebounds at the same angle with

  3. 1) can the position-time graph for the motion of an object be a horizontal line?explain

    - so its yes? 2) can the positon-time graph bea vertical line, explain -so its yes

  4. A parallel-plate capacitor with air between the plates has an area A= 2.00 x 10^-4 m^2 and a plate

    separation d = 1.00 mm. Find its capacitance.

  6. If 500 J of work are required to carry a charged particle between two points with a potential difference of 40V, the magnitude of the charge on the particle is:

    a) 0.040 C b) 12.5 C c) 20C D) cannot be computed unless the path is give e) none of these My

  7. A ladder 20m long rest against a vertical wall so that the foot of the ladder is 9m long. Find correct to the nearest degree the angle that the ladder makes with the wall.

  8. 1.A bus travels 400 m between two stops. It starts from rest and accelerates at 1.50 m/s^2 until it reaches a velocity of 9.00 m/s. The bus continues at this velocity and then decelerates at 2 m/s^2 until it comes to a halt. Find the total time required

  9. Radioactive Decay Energy Quick Check

    Polonium has a large, unstable nucleus. Through which process is it most likely to become stable? gamma decay beta-plus decay beta-minus decay alpha decay(✔️) Which type of energy does alpha decay generate? Potential

  11. The range of human hearing extends from approximately 20 Hz to 20000 Hz. Find the wavelength of these extremes when the speed of sound in air is equal to 343 m/s.

  12. A spaceship in deep space has a velocity of 4000 km/s and an acceleration in the forward direction of 6 m/s2. What is the acceleration of a ball relative to the spaceship after it is released in this spaceship?

  13. On the surface of the Moon, a 91.0-kg physics teacher weighs only 145.6 N. What is the value of the Moon’s gravitational field at its surface?

  14. A small glider is placed against a compressed spring at the bottom of an air track that slopes upward at an angle of 38.0 ∘ above the horizontal. The glider has mass 6.00×10−2 kg . The spring has 630 N/m and negligible mass. When the spring is

  16. A 39-turn circular coil of radius 3.20 cm and resistance 1.00 Ω is placed in a magnetic field directed perpendicular to the plane of the coil. The magnitude of the magnetic field varies in time according to the expression B = 0.010 0t + 0.040 0t2, where B

  17. An object projected horizontally from the top of a cliff with a velocity of 7 metre per second and land on the ground level a point 56m from the base of the cliff calculate the height of the cliff

  18. what forms of energy are involved in the following situations? (choices: kinetic energy, potential energy - gravitational potential energy, elastic potential energy)

    a. a bicycle coasting along a level road b. heating water c. throwing a football d. winding

  19. A) A 600 kg steel beam is supported by the two ropes shown in (Figure 1). Calculate the tension in the rope.

    Express your answer to two significant figures and include the appropriate units. B) The rope can support a maximum tension of 3200 N . Is this rope

  21. We were doing a refraction lab where you passed a lazer beam through a water in a semi-circular dish. I was wondering why we used a semi-circular shape?

  22. A merry-go-round is a common piece of playground equipment. A 2.4 m diameter merry-go-round with a mass of 300 kg is spinning at 22 rpm. John runs tangent to the merry-go-round at 5.0 m/s, in the same direction that it is turning, and jumps onto the outer

  23. The track near the top of your favorite roller coaster has a circular shape with a diameter of 36 m. When you are at the top, you feel as if you weigh only one-fifth of your weight on the ground. What is the speed of the roller coaster?

  24. How many days does it take for a perfect blackbody cube (0.0100m on a side, 30.0 degree C)to radiate the same amount of energy that a one-hundred-watt light bulb uses in one hour?

    I got no idea to do it. Please give me some hints!!!Thanks!!!

  26. Two forces 3N and 4N on a body in directions due North and due East respectively.Calculate their equilibrant.

  27. An ideal massless spring is fixed to the wall at one end. A block of mass M attached to the other end of the spring oscillates with amplitude A on a frictionless, horizontal surface. The maximum speed of the block is V_m. The force constant of the spring

  28. a small rock with mass 0.20 kg is released from rest at point A which is at the top edge of a large, hemispherical bowl with radius R = .5m. assume that the size of the rock is small compared to R, so that the rock can be treated as a particle, and assume

  29. A stationary source produces a sound wave at a frequency of 100 Hz. The wave travels at 1125 feet per second. A car is moving toward the sound

    source at a speed of 200 feet per second. Item 3 What is the wavelength of the stationary sound source and the

  31. A wheel with rotational inertia I is mounted on a fixed, fricitonless axle. The angular speed w of the wheel is inccreased from zero to w_f in a time interval T.

    1: What is the average net torque on the wheel during the time interval, T? a) w_f/T b)w_f/T^2

  32. 1. A slingshot is used to launch a 5.00-gram rock. The effective spring constant of the slingshot is 200 N/m. By what distance must the slingshot be stretched in order to launch the rock at 20.0 m/s?

  33. A receiving antenna becomes misaligned by 30° to its original position. The power of the received signal in this new position is 12µW.

    Wavelength = 0.016 m I calculated the power received in the original position as 1.04 x 10^-5 W What I need to find out

  34. How much work must be done to stop a 1250 kg car traveling at 105 km/h?

  36. A car, in overtaking trailer, uniformly accelerated its speed from 40 kph to 90 kph in 8 seconds. Calculate the distance traveled during the period of acceleration.

  37. A tension of 6000 newtons is experienced by the elevator cable of an elevator moving upward with an acceleration of 2m/s^2. what is the mass of the elevator

  38. A motorist traveling with a constant speed of 15m/s passes a school-crossing corner, where the speed limit is 10m/s. Just as the motorist passes, a police officer on a motorcycle at the corner starts off in pursuit with constant acceleration of 3m/s^2.

  39. Workers have loaded a delivery truck in such a way that its center of gravity is only slightly forward of the rear axle. .63m in front of the rear wheels and 2.3m behind the front wheels. The mass of the truck and its contents is 9155 kg. Find the

  41. Electrons are ejected from a metallic surface with speeds ranging up to 4.50x10^5 m/s when light with a wavelength of 615nm is used. (a) What is the work function of the metal? (b) What is the cutoff frequency for this surface?

  42. The gravitational field strenght on the moon is 1.63N/kg. If a rock on the moon weights 2000N, how much does the same rock weigh on the earth?

  43. please check:

    Which of the following energy forms is associated with an object in motion? a. potential energy b. elastic potential energy c. nonmechanical energy d. kinetic energy i think its B Which of the following energy forms is associated with an

  44. Thanks for any help :)

    Four 20 ohm resistors are connected in parallel and the combination is connected to a 20V emf device. The current is: A) 0.25A B) 1.0 A C) 4.0 A D) 5.0 A E) 100 E Parallel circuits: I know that the voltage is 20V and the Resistance is

  46. In the parallel circuit, if the current put out

    by the battery is 3 A and the current through R1 is 1 A, what is the current through R2?

  47. A horse runs 15 m [N 23° E] and then 32 m [S 35° E]. What is the total displacement of the horse?

    I can't even visualise this... My friend told me the basic steps on how to solve it, but I got the wrong answer anyways... d1 = 15 m [N 23° E] d1x = 15m sin

  48. A 72.0 kg swimmer jumps into the old swimming hole from a tree limb that is 4.00 m above the water.

    Part A- Use energy conservation to find his speed just as he hits the water if he just holds his nose and drops in. Part B- Use energy conservation to find

  49. A potter’s wheel with rotational inertia of 45 kg m2, is spinning freely at 40 rpm. The potter drops a lump of clay onto the wheel where it sticks a distance 1.2 m from the rotational axis at the wheel’s center. If the subsequent angular speed of the

  51. A boy can throw a ball a maximum horizontal distance of R on a level field. How far can he throw the same ball vertically upward? Assume that his muscles give the ball the same speed in each case.

  52. Blood flow rates in the umbilical cord can be found by measuring the Doppler shift of the ultrasound signal reflected by the red blood cells. If the source emits a frequency f, what is the measured reflected frequency fR? Assume that all of the red blood

  53. The hydrogen atom contains a proton, mass 1.67 10-27 kg, and an electron, mass 9.11 10-31 kg. The average distance between them is 5.3 10-11 m. The charge of the proton is the same size, opposite sign of the electron.

    a)What is the magnitude of the average

  54. The linear impulse delivered by the hit of a boxer is 97.7 N·s during the 0.368 s of contact.

    What is the magnitude of the average force exerted on the glove by the other boxer? Answer in units of N.

  55. Black Holes are suspected when a visible star is being noticeably pulled by an invisible partner that is more than 3 times as massive as the Sun. A red giant star is accelerated in a linear direction by gravity at 0.075 m/s2 towards an object that is 9.4

  56. A bike wheel rotates uniformly through 2 revolutions in 3 seconds.

    a) what is the period of the wheel's rotation? T=3rev/2s=1.5s b) what is the frequency of the wheel's rotation? (in Hertz) f=1/T =1/1.5 =.666Hz c) what is the angular speed of the

  57. A 15kg box is resting on a hill forming an angle with the horizontal. The coefficient of static friction for the box on the surface is 0.45. Calculate the maximum angle of the incline before the box starts to move.

    Steps included would be great, I have the

  58. Bob is pulling a 30kg filing cabinet with a force of 200N , but the filing cabinet refuses to move. The coefficient of static friction between the filing cabinet and the floor is 0.80.

    What is the magnitude of the friction force on the filing cabinet?

  59. A jack exerts a vertical force of 4.5 x 10^ 3 newtons to raise a car 0.25 meter. How much work is done by the jack?

  60. A loop circuit has a resistance of R1 and a current of 2.2 A. The current is reduced to 1.7 A when an additional 3 Ω resistor is added in series with R1. What is the value of R1? Assume the internal resistance of the source of emf is zero.

  61. A ball is allowed to fall freely from certain heightn. What distance it covers in 1st second?

  62. A 1000N crate is being pushed across a level floor at a constant speed by a force F of 300N at an angle of 20.0 degrees. (a) What is the coefficient of kinetic friction between the crate and the floor? (b) If the 300-N force is instead pulling the block at

  63. I need help with this question with explanation. Thanks

    A particle of mass m starts from rest at position x = 0 and time t = 0. It moves along the positive x-axis under the influence of a single force Fx = bt, where b is a constant. The velocity v of the

  64. An escalator carries 60 people of average mass 70 kg to a height of 5m in one minute.Find the power needed to do this.

  65. while on the moon, the Apollo astronauts enjoyed the effect of a gravity much smaller than that on earth. if Neil Armstrong jumped up on the moon with an initial speed of 1.51 m/s to a height of 0.700m, what amount of gravitational acceleration did he

  66. A 300 g block on a 54.0 cm -long string swings in a circle on a horizontal, frictionless table at 85.0 rpm .

    What is the speed of the block? Express your answer with the appropriate units. What is the tension in the string? Express your answer with the

  67. A box with mass 13.0 kg moves on a ramp that is inclined at an angle of 55.0∘ above the horizontal. The coefficient of kinetic friction between the box and the ramp surface is μk = 0.300.

    FIND A) Calculate the magnitude of the acceleration of the box if

  68. I need help with this question please. A solid cylinder of mass m and radius R has a string wound around it. A person holding the string pulls it vertically upward such that the cylinder is suspended in midair for a brief time interval (change in)t and its

  69. a bomb is dropped from an airplane travelling horizontally with a speed of 300 mi/hr if the airplane is 10000ft. above the ground, how far from the target must it be released, neglect friction?

  70. Jerry bicycles from his dorm to the local fitness center: 3.06 miles east and 2.07 miles north. Cindy's apartment is located 1.5 miles west of Jerry's dorm. If Cindy is able to meet Jerry at the fitness center by bicycling in a straight line, what is the

  71. A car of mass 600 kg is moving at a speed of 20 m/s.it collides with a stationary car of mass 900 kg.if the first car bounces back at 4 m/s,at what speed does the second car move after the collusion?

  72. A white billiard ball with mass mw = 1.43 kg is moving directly to the right with a speed of v = 3.4 m/s and collides elastically with a black billiard ball with the same mass mb = 1.43 kg that is initially at rest. The two collide elastically and the

  73. "An airplane is climbing at an angle of 15 degrees to the horizontal with the sun directly overhead. The shadow of the airplane is observed to be moving across the ground at 200 km/h. How long does it take for the plane to increase its altitude by 1000 m"?

  74. Two point charges that have charge values of 4.0 X 10^-6 C and -8.0 X 10^-6 C, respectively, are separated by 2.4 X 10^-2 m. What is the mutual force between them, given that kC = 8.99 X 10^9 Nm^2/C^2?

    I got the Felectric as -5.0 X 10^2 N, but I'm not sure

  75. A spring oriented vertically is attached to a hard horizontal surface as in the figure below. The spring has a force constant of 1.64 kN/m. How much is the spring compressed when a object of mass m = 2.35 kg is placed on top of the spring and the system is

  76. Problem 2- A 350 kg roller coaster starts from rest at point A and slides down the frictionless loop-the-loop shown in the figure.

    a) How fast is the roller coaster moving at point B? b) How hard does it press against the track at point B?

  77. Amechanic pushes a 2.50*10^3 kg car from rest to a speed of v, doing 5.00*10^3 Jof work in the process, During this time, the car moves 25.0m. Neglecting friction between car and road, find (a) v and (b) the horizontal force exerted on the car

  78. Ammeter 1 reads 0.20 A.

    a. What should ammeter 3 indicate? b. What should ammeter 4 indicate? Given: RA = 22-OHM RB = 13-OHM A1 = 0.20 A Ammeter 2 reads 0.15A. a. Find the voltage across the 22-ohm resistor? b. Find the voltage across the 15-ohm resistor?

  79. The cheetah is one of the fastest-accelerating animals, because it can go from rest to 18.2 m/s (about 41 mi/h) in 2.7 s. If its mass is 114 kg, determine the average power developed by the cheetah during the acceleration phase of its motion. Express your

  80. Consider the circuit shown in the figure below. (Assume R1 = 12.0 Ω and R2 = 6.00 Ω.)

    Read this for the figure - A rectangular circuit begins at its left side at a 25.0 V battery with the positive terminal on top. From the battery, the circuit extends up

  81. At the start of your throw of a 5.6-kg bowling ball, your arm is straight behind you and horizontal (Figure 1) . Your arm is 0.64 m long, has a rotational inertia of 0.48 kg⋅m2 and has a mass of 3.5 kg with its center of mass 0.28 m from your shoulder

  82. A ball is thrown at 21m/s at 30degree above the horizontal from the top of a roof 16m high.calculate the time of flight

  83. A helicopter is ascending vertically with a speed of 5.20 m/s. AT the height of 125m above the earth, a package is dropped from a window.How much time does it take for the package to reach the ground.

    ****Note: Please show the steps.

  84. The gravitational force of attraction between two students sitting at their desks in physics class is 2.34 ✕ 10^-8 N. If one student has a mass of 45.0 kg and the other student has a mass of 61.6 kg, how far apart are the students sitting?

  85. A 45 kg girl is sitting on one end of a see-saw, 0.6 m away from the the pivot pt. How far away form the pivot pt must a 60 kg boy sit on the other side in order for the see saw o be balanced?

  86. A dragster accelerates from rest for a distance of 450m at 14 m/s^2. A parachute is then used to slow it down to a stop if the parachute gives the dragster an acceleration of -7m/s^2 how far has the dragster traveled before stopping?

  87. Pepe and Alfredo are resting on an offshore raft after a swim. They estimate that 3m separates a trough and an adjacent crest of surface waves on the lake. They count 14 crests that pass by the raft in 20 seconds. Calculate how fast the waves are moving.

  88. A 2.1kg brass ball is transported to the Moon.

    a)What is the mass of the brass ball on the earth and on the moon? Wouldn't it be 2.1kg for the earth as well as for the moon? b)Determing the weight of thee brass ball on the earth. F_g=(G*m_ball*m_earth)/r^2

  89. tarzan swings a vine of length 4m in a vertical circle under the influence of gravity. When the vine makes an angle of 20degrees with the vertical, Tarzan has a speed of 5m/s. Find centripetal acceleration, tangential acceleration and the resultant

  90. Carol drops a stone into a mineshaft 122.5m deep. Calculate the time from when she hears it hit the bottom of the shaft. Assume the speed of sound in the air 343 m/s.

  91. A hoop of mass M = 3 kg and radius R = 0.5 m rolls without slipping down a hill, as shown in the figure. The lack of slipping means that when the center of mass of the hoop has speed v, the tangential speed of the hoop relative to the center of mass is

  92. An inductor used in a dc power supply has an inductance of 12 H and a resistance of 180 ohms and carries a current of .300 A. (a) How much energy is stored in the magnetic field? (b) At what rate is thermal energy developed in the inductor?

    ok once again I

  93. In a location in outer space far from all other objects, a nucleus whose mass is 3.57232e-25 kg and which is initially at rest undergoes spontaneous "alpha" decay. The original nucleus disappears, and two new particles appear: a He-4 nucleus of mass

  94. A ball traveling with an initial momentum of 4.5 kgm/s bounces off a wall and comes back in the opposite direction with a momentum of –3.5 kgm/s. What is the change in momentum?

    Answer: -3.5-4.5= -8 kgm/s?

  95. A 1200 kg car pushes a 2100 kg truck that has a dead battery to the right. When the driver steps on the accelerator, the drive wheels of the car push against the ground with a force of 4500 N . What is the magnitude of the force the car applies to the

  96. A simple pendulum is made from a 0.65m long string and a small ball attached to its free end. The ball is pulled to one side through a small angle and then released from rest. After the ball is released, how much time elapses before it attains its greatest

  97. An automobile moving at a constant velocity of 15m/s passes a gasoline station. Two seconds later, another automobile leaves the gasoline station and accelerates at a constant rate of 2m/s^2 in the same direction. How soon does the second autombile

  98. A box accidentally falls from the back of a truck and hits the ground with a speed of 15m/s. It slides along the ground for a distance of 45 m before coming to rest. Determine

    a) the length of time the box slides before stopping c) the time it takes to

  99. A 10.-newton force is required to hold a

    stretched spring 0.20 meter from its rest position. What is the potential energy stored in the stretched spring?

  100. To give a 20-kg child a ride, two teenagers pull on a 3.6-kg sled with ropes, as indicated in the figure. Both teenagers pull with a force of 55 N at an angle of 35 ∘ relative to the forward direction, which is the direction of motion. In addition, the

  101. You want to design a helium-filled balloon that will lift a total payload of 1225 kg. What volume of helium is needed to just barely lift this payload?

  102. A small block on a frictionless horizontal surface has a mass of 2.50×10−2 Kg. It is attached to a massless cord passing through a hole in the surface. The block is originally revolving at a distance of 0.300 m from the hole with an angular speed of

  103. A block of mass m = 2.00 kg rests on the left edge of a block of mass M = 8.00 kg. The

    coefficient of kinetic friction between the two blocks is 0.300, and the surface on which the 8.00- kg block rests is frictionless. A constant horizontal force of

  104. A car is traveling on a level horizontal rode comes to a bridge during a storm and finds the bridge washed out. The driver must get to the other side, so he decides to try leaping it with his car. The side of the road the car is on 21.3m above the river,

  105. A horizontal pipe narrows from a diameter of 10 to 5 cm. For an incompressible fluid flowing from the larger diameter to the smaller:

    Question 5 options: 1.the velocity and pressure both increase. 2.the velocity increases and the pressure decreases. 3.the

  106. The period of motion of an object-spring system is T = 0.474 s when an object of mass m = 296 g is attached to the spring.

    (a) Find the frequency of motion in hertz. _______Hz (b) Find the force constant of the spring. _______N/m (c) If the total energy of

  107. A 0.006-kg bullet traveling horizontally with a speed of 1.00 103 m/s enters an 21.1-kg door, imbedding itself 10.4 cm from the side opposite the hinges as in the figure below. The 1.00-m-wide door is free to swing on its hinges.

    (c) At what angular speed

  108. If a man weighs 900 N on the earth, what would he weigh on jupiter, where acceleration due to gravity is 25.9 m/s^2?

  109. 1.For the following simple see-saw calculate: 1. the load that could be lifed, 2. the maechanical advantage (assume the lever is 100% efficient).

  110. A simple wheel and axle is used to lift a bucket of water from a well the radii of the wheel and axle are 20cm and 4cm respectively determine the theoretical effort required to lift a load of 30N assuming no energy losses

Pages

  1. 1
  2. 2
  3. 3
  4. 4
  5. 5
  6. 6
  7. 7
  8. 8
  9. 9
  10. 10
  11. 11
  12. 12
  13. 13
  14. 14
  15. 15
  16. 16
  17. 17
  18. 18
  19. 19
  20. 20
  21. 21
  22. 22
  23. 23
  24. 24
  25. 25
  26. 26
  27. 27
  28. 28
  29. 29
  30. 30
  31. 31
  32. 32
  33. 33
  34. 34
  35. 35
  36. 36
  37. 37
  38. 38
  39. 39
  40. 40
  41. 41
  42. 42
  43. 43
  44. 44
  45. 45
  46. 46
  47. 47
  48. 48
  49. 49
  50. 50
  51. 51
  52. 52
  53. 53
  54. 54
  55. 55
  56. 56
  57. 57
  58. 58
  59. 59
  60. 60
  61. 61
  62. 62
  63. 63
  64. 64
  65. 65
  66. 66
  67. 67
  68. 68
  69. 69
  70. 70
  71. 71
  72. 72
  73. 73
  74. 74
  75. 75
  76. 76
  77. 77
  78. 78
  79. 79
  80. 80
  81. 81
  82. 82
  83. 83
  84. 84
  85. 85
  86. 86
  87. 87
  88. 88
  89. 89
  90. 90
  91. 91
  92. 92
  93. 93
  94. 94
  95. 95
  96. 96
  97. 97
  98. 98
  99. 99
  100. 100