Assigned Jan 29 2008, Due Feb 5 2008 9.2 (two sketches required, draw them in "top down" fashion, with the rotation in the plane of the paper.) 9.14, 9.15 Coriolis Force Problem 1) An aircraft is flying 800 km/h in latitude 55 degrees N (theta = 90 degrees - latitude). Find the angle through which it must tilt its wings to compensate for the horizontal component of the Coriolis force. Coriolis Force Problem 2) Coriolis force for a projectile: If a projectile is fired due east from a point on the Earth's surface that is at latitude lambda (colatitude = pi/2 - lambda) with a velocity of magnitude V0, and at an the angle of inclination with respect to the horizontal of alpha, show that the lateral deflection when the projecile strikes the ground is: d = 4 (V0^3/g^2) * [Omega*sin(lambda)*sin^2(alpha)*cos(alpha)] where Omega is the rotation frequency of the Earth. --------------------------------------------------------------- Assigned Feb 7 2008 Due Feb 14 2008 10.14, 10.16 (angular momentum conserved before it hits, energy conserved after) 10.22, 10.36 (delayed to Feb 19) ---------------------------------------------- Assigned Feb 20 2008, Due Feb 28 2008 10.42 10.44 10.50 10.52 (the problem refers to free precession rate found in Eq. 10.06, it should say Eq. 10.96) ---------------------------------------------- RIDGID BODY ROTATION Take Home Problems: Assigned Feb 25 2008 Due March 4 2008 1) A double-mass pendulum is made of a massless rod of length b, with two masses attached to it. The first mass (m_1) is attached at the end (at b). The second mass (m_2) is attached halfway up (at b/2). The top of the rod (at 0) is attached to the ceiling, free to swing any way it wants. Take the body fixed axes as e_1: along the length of the pendulum e_2: in the plane, perpendicular to e_1 e_3: out of the page. a) Find the moment of inertia tensor. b) Now assume the pendulum only swings in the plane of the page (making an angle \theta with the vertical). Write down the angular velocity (\omega) vector, and then the angular momentum (L) vector. (remember, L= I \omega). c) Gravity acts in the "down" direction. Write down the gravity vector in e_1,e_2,e_3 basis. Now calculate the torque (r x F) due to gravity and set it equal to L-dot. (It might be less messy to do the two masses separately, and then add). d) Write down a differential equation for small oscillations of this pendulum (ie, sin(theta) is approx = theta). e) [extra credit] You can of course do this problem with Lagrangian Mechanics. Write down the Lagrangian, and show that you can get the same equation of motion (in theta) as in parts (c, d). --------- Assigned March 6, 2008, Due March 13, 2008 13.6 13.10 13.12 13.26 --------------------------------------------- Assigned March 13, Due March 25 11.18 11.22 11.24 11.26 11.28 --------------------------------------------- Assigned March 27, Due April 3 14.8 14.11 14.14 14.18 14.20: You can determine r_min from angular momentum L and energy of the projectile. Recall the angular momentum relations we used in lecture. --------------------------------------------- ============================================= HAMILTONIAN, NORMAL MODES, SCATTERING Take home exam due thurs April 17 See figures for probs 1, 2 here: http://www.physics.rutgers.edu/ugrad/382s08/382_exam_fig.jpg 1) A massless string passes over a small massless pulley and carries mass 2m on one end. On the other end of the string is a mass m. Below this mass m, is another mass m, supported by a spring with spring constant k. Find the Hamiltonian for this system, using x, the distance of the first mass m beneath the pulley. and y, the extension of the spring, as generalized coordinates. If the system is released from rest with the spring unextended, find the positions of the masses at any later time. ------ 2) A spring of negligible mass and spring constant k, supports a mass m. Beneath this mass is attached a second identical spring and another mass m. Use x and y as displacements of the masses from equilibrium. Consider only vertical motion. How many normal modes are there? What are the frequencies of oscillation for the various normal modes? --------- A beam of particles strikes a wall containing 2*10^29 atoms/m^3. (this is density or mass/V) Each atom behaves as a hard sphere of radius 3*10^-15m. Find the thickness of the wall such that exactly half the incident particles go through without scattering. What thickness would be needed to stop all but one particle in 10^6? ========================================== Assigned April 22 Due April 29 15.8 15.26 15.28 15.50 15.76