You are in an old spy movie, and have been locked into a small room (volume 1000 ft). You suddenly realize that a poison gas has just started entering the room through a ventilation duct. Recognizing the type of poison from its smell, you know that if the gas reaches a concentration of 100 mg/m, you will die instantly, but that you are safe as long as the concentration is less than 100 mg/m. If the ventilation air flow rate in the room is 100 ft/min and the incoming gas concentration is 200 mg/m, how long do you have to escape?

An uncharged nonconductive hollow sphere of radius 18.0 cm surrounds a 12.0 µc charge located at the origin of a cartesian coordinate system. a drill with a radius of 1.00 mm is aligned along the z axis, and a hole is drilled in the sphere. calculate the electric flux through the hole.

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 ..

Ahot-air balloonist, rising vertically with a constant speed of 5.00 m/s releases a sandbag at the instant the balloon is 40.0 m above the ground. after it is released, the sandbag encounters no appreciable air drag. compute the velocity of the sandbag at 0.250 s after its release.