1. A

    Angular Momentum

    In playground there is a small merry-go-round of radius 1.25m and mass 175kg. Assume the merry -go-round to be a uniform disc. A child of mass 45kg runs at a speed of 3.0 m/s tangent to the rim of the merry-go-round (initially at rest) and jumps on. If we neglect friction, what is the angular...
  2. A

    Angular Momentum

    Let us compare the angular momentum of Mars (L(mars)) in its orbit around the Sun to that of Earth (L(earth)). The mean orbital speed of Mars is 24km/s. whereas that of Earth is 30km/s. The mean orbital radius of Mars is 228×10^6 km, whereas that Earth is 150×10^6. If the mass of Mars is 11%...
  3. A

    Angular Momentum

    The angular momentum of a rotating object is initially L(initial)=2i+4j and 2s later it is L(final)=3i+8j. The units are in kg·m2/s. The torque that produces the change in angular momentum is. A)-0.5N·mi – 2N·mj B) 0.5N·mi + 2N·mj C) -1N·mi – 4N·mj D) 1N·mi + 4N·mj E) None of...
  4. D

    angular momentum

    a pole with a mass of M, and a length of L is hung on a nail through its top end, so that it can swing freely. a ball with a mass of m moving horizontally hits the bottom end of the pole and sticks to it, the pole rises in circular motion to an angle of "alpha". there is no friction with the air...
  5. W

    2d collision ,angular velocity, friction

    im developing a 2d physics engine. its very simple at the moment, circles can collide with each other and with stationary polygons. but i would like to add a new dimention to my solution: friction. this would then also introduce angular velocity to my particles. so here is my question: at...
  6. K

    angular momentum problem

    hey guys, if can please help with this problem: a unifrom rod of length 3.2m and mass 6kg is supported by a hinge at one end and is freee to rotate in the vertical plane. the rod is released from rest in te position shown. a particle of mass m is supported by a thin string of length 3m from te...
  7. B

    Angular momentum for several particles

    For a system of just three particles, can any show in detail the argument leading from L=Sum (from a=1 to N) of l_a = Sum ( from a=1 to N) of r_aX P_a to L'=external torque. Can any show some steps or have a link to where this is explained?
  8. K

    Classical Mechanics: angular frequency

    I take a book that is 30cm x 20 cm x 3 cm and is held shut by a rubber band, and I throw it into the air spinning about an axis that is close to the book's shortest symmetry axis at 180 rpm. What is the angular frequency of the small oscillations of its axis of rotation? What if I spin it about...
  9. M

    Conservation of Angular Momentum

    A 500 gram piece of putty falls straight down and sticks to a 4 kg rotating solid disk below. The uniform disk has a radius of 3 meters, and the putty hits the disk 2.5 meters from its center. You may neglect all forces other than that of the collision. a- If the disk was initially rotating at...
  10. G

    Another question! Angular acceleration! Torque! HELP!

    I have a question that I'm not sure what to do with! HELP! A wheel of radius 0.2 m is rotating around its axis with initial angular velocity of 30 radians/s clockwise. A braking force of 6.0 N is applied tangentially at the rim. 5.0 s later the angular velocity of the wheel is 10 radians/s...
  11. J

    Angular velocity

    a constant torque of 4.81N-m is applied to a rotating solid disk of radius 15cm and a mass 9.76kg. what is the angular velocity of the disk after 10 seconds?
  12. A

    Angular acceleration

    Hey guys. I got this poll which is at one side connected to a wall and is being released from a horizontal state. his length is L and mass m. I need to find the angular acceleration of the poll as a function of the angle. I got this answer in the pic but according to them the answer should be...
  13. disclaimer

    angular velocity, center of rotation

    Hi, here's the problem: Any help or hint appreciated.
  14. O

    angular conservation of momentum/collision

    The drawing shows a collision between two pucks on an air-hockey table. Puck A has a mass of 0.038 kg and is moving along the x axis with a velocity of +5.5 m/s. It makes a collision with puck B, which has a mass of 0.068 kg and is initially at rest. The collision is not head-on. After the...
  15. A

    Angular velocity

    I have this pole with mass M and length L which is on a flat table with no friction. Another particle, which has the same mass M hits him on its edge with velocity V, which is vertical to the pole. then, the particle sticks to the pole and they move together. I need to find both the Angular...
  16. P

    angular velocity

    A hoop of radius R and a solid cylinder of radius R are both started from rest at the top of an incline plane. They both roll down the plane without slipping. Which one gets to the bottom first and (important!) why? Explain your answer in complete, concise, coherent sentences.
  17. A

    help with angular acceleration prob

    heres the problem: A penny rests on a record at a radius of r=0.200m. The record player is turned on and the record steadily accelerates with angular acceleration alpha = 20.0 rad/s^2. The coefficient of static friction between the record and the penny is 0.500. At what time will the penny...