What is the best description of sound waves? A. A source vibrates up and down, causing air molecules to move up and down perpendicular to the direction the wave is transmitted.

B. A source vibrates back and forth, causing air molecules to move back and forth in the same direction that the wave is transmitted.

C. A source vibrates up and down and back and forth, causing air molecules to move in a circular motion as the wave is transmitted.

D. A source ejects a ring of high-velocity air molecules that travel from the source to a listener.

Which of the following describes something an engineer would probably do first when developing new technology meant to reduce ocean pollution? o a. evaluate the benefits and challenges of using certain chemicals to purify water. o b. research new scientific findings in regard to ocean cleanup. o c. identify the need to reduce ocean pollution. o d. research what has been done in the past to clean up oceanic oil residue.

Astone dropped into a well is heard to strike the water after 8seconds. find the depth of the well if the velocity of sound is 350m/s

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 ..