Physics

posted by .

One-fourth of length L is hanging down over the edge of a frictionless, table. The rope has an uniform, linear density (mass per unit length), lambda, and the end already on the table is held by a person. a) How much work does the person do when she pulls on the rope to raise the rope and from this the work done. Note that this force is variable because at different times, different amounts of rope are hanging over the edge. b) Suppose the segment of the rope initially hanging over the edge of the table has all of its mass concentrated at its center of mass. Find the work necessary to raise this to table height. You probably find this approach simpler than that of part a). How do the answers compare and why is this so?

  • Physics -

    I am not certain how to approach this. Sure a) asks for Work = F*x, so I take the integral of F*x with F= T-mg? b) Takes center of mass, but how do you get the center of mass of something that is constantly changing its position?

  • Physics -

    idk help

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. physics

    A rod of length 30.0 cm has linear density(mass-per-length) given by [lambda]= 50.0g/m + 20.0x g/(m^2) where x is the distance from one end, measured in meters.(a) What is the mass of the rod?
  2. physics

    A chain of length l and mass ë per unit length is fully open and is held on a high frictionless table with y1 of its length hanging from the side of the table as shown in figure. When released, it starts slipping off the table. By …
  3. Physics

    A chain is held on a frictionless table with 1/3 of its length hanging over the edge. If the chain has length L = 33 cm and mass m = 21 g, how much work is required to pull the hanging part back onto the table?
  4. Physics

    A uniform chain of total mass m is laid out straight on a frictionless table and held stationary so that one-quarter of its length, L = 1.79 m, is hanging vertically over the edge of the table. The chain is then released. Determine …
  5. Newton's law

    7. A uniform flexible chain of length l, with weight per unit length lamba, passes over a small, frictionless, massless pulley. It is released from a rest position with a length of chain x hanging from one side and a length l-x from …
  6. Physics

    Masses 15 kg and 8 kg are connected by a light string that passes over a friction-less pulley with the 15 kg mass on a table and the 8 kg mass hanging off the edge. The acceleration of gravity is 9.8 m/s2. If the 15 kg mass, initially …
  7. physics

    A 1.2kg object is placed on a frictionless table and is attached to a hanging mass using a light string over a frictionless pulley in a fletcher's trolley arrangement. The 1.20kg object accelerates along the table at 2.31m/s while …
  8. physics

    A rod of length 30.0 cm has linear density (mass-per-length) given by lambda = 50.0 g/m + 20.0 y g/m2 , where y is the distance from one end, measured in meters. (a) What is the mass of the rod?
  9. Physics

    A uniform rope with length L and mass m is held at one end and whirled in a horizontal circle with angular velocity w. You can ignore the force of gravity on the rope. (a) At a point on the rope a distance r from the end that is held, …
  10. physics

    The figure above shows a chain being held on a table with one quarter of its length hanging over the edge. Friction is negligible. The chain has length L = 24 cm and mass m = 0.012 kg. Calculate how much work is required to pull the …

More Similar Questions