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Q1 A particle of mass m slides on the surface of a smooth table. It is connected to a light inextensible string of length l that passes through a frictionless hole in the center of the table and is then attached to a second particle of mass M . You may assume that the mass M moves only in a vertical direction, and that the neither particle ever gets close to the hole in the table. Gravity acts vertically downward. θ r m M g a) Using the co-ordinates r and θ, write down the Lagrangian that de- scribes the motion of the two-particle system, and from it obtain the equations of motion for r and θ. b) By identifying a suitable conserved quantity, reduce your two equations of motion for r and θ to a single second-order equation for r. c) Reduce your second-order equation from part (b) to a first-order equa- tion. This equation will contain two parameters that depend on the motion at time t = 0. Express the two parameters in terms of r(0), ˙ r(0) and ˙ θ(0). d) Obtain the Hamiltonian of the system, and write down Hamilton’s equations for the evolution of the co-ordinates and the generalized mo- menta.

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  • Q1 A particle of mass m slides on the surface of a smooth table. It isconnected to a light inextensible string of length l that passes through africtionless hole in the center of the table and is then attached to a secondparticle of mass M . You may assume that the mass M moves only in avertical direction, and that the neither particle ever gets close to the hole inthe table. Gravity acts vertically downward.

    r m

    M

    g

    a) Using the co-ordinates r and , write down the Lagrangian that de-scribes the motion of the two-particle system, and from it obtain theequations of motion for r and .

    b) By identifying a suitable conserved quantity, reduce your two equationsof motion for r and to a single second-order equation for r.

    c) Reduce your second-order equation from part (b) to a first-order equa-tion. This equation will contain two parameters that depend on themotion at time t = 0. Express the two parameters in terms of r(0),r(0) and (0).

    d) Obtain the Hamiltonian of the system, and write down Hamiltonsequations for the evolution of the co-ordinates and the generalized mo-menta.