A small disk is on top of a large disk: The big disk on the bottom has radius = 2r. In Diagram 1 the little disk on the top has radius = r. The top disk may be small, but it is very heavy. The top disk has twice the mass (2m) as the bottom disk (m). The bottom disk is spinning at ω when the top disk drops on to it. The top disk had no angular velocity when it was dropped.
Derive an equation for the angular velocity of both disks after the collision in terms of the given variables and any universal constants.
Derive an equation for the change in kinetic energy of the system as a result of the collision in terms of the given variables and any universal constants. If the change in kinetic energy is 0, state that and justify your answer.
The same experiment is duplicated with a new top disk with the same mass (2m) but double the radius (2r). Would the change in kinetic energy of the system be greater than, less than, or the same as the initial collision described in part A and B. Justify your answer in using physics principles, diagrams and equations.

Awoman stands a distance d from a loud motor that emits sound uniformly in all directions. the sound intensity at her position is an uncomfortable 2.0×10-3 w/m2. at a distance 2.6 times as far from the motor, what are (a) the sound intensity and (b) the sound intensity level relative to the threshold of hearing?

Dinate system, and a charge q = - 2.00 nc is placed s2 10 n> c. (a) what is the change in electric potential energy when the dipole moment of a molecule changes its orientation with respect to es from parallel to perpendicular? (b) at what absolute temperature t is the average translational kinetic energy 32 kt of a molecule equal to the change in potential energy calculated in part(: abovethistemperature,thermalagitationprevents the dipoles from aligning with the electric field.) placed in a uniform electric field e with magnitude 1.6 * 6 on the positive x-axis at x = 4.00 cm. (a) if a third charge q3 = +6.00 nc is now placed at the point x = 4.00 cm, y = 3.00 cm, find the x- and y-components of the total force exerted on this charge by the other two. (b) find the magnitude and direction of figure p21.62 ll uu 21.55 . torque on a dipole. an electric dipole with dipole moment ps is in a uniform external electric field es. (a) find the orientations of the dipole for which the torque on the dipole is zero. (b) which of the orientations in part (a) is stable, and which is unstable? (hint: consider a small rotation away from the equi- librium position and see what happens.) (c) show that for the stable orientation in part (b), the dipole’s own electric field tends to oppose the external field. 21.62 ..

How do we measure or think of speed in the united states?