Hot oil (cp = 2200 j/kg·k) is to be cooled by water (cp = 4180 j/kg·k) in a 2-shell-passes and 12-tube-passes heat exchanger. the tubes are thin-walled and are made of copper with a diameter of 1.8 cm. the length of each tube pass in the heat exchanger is 3 m, and the overall heat transfer coefficient is 340 w/m2 ·k. water flows through the tubes at a total rate of 0.1 kg/s, and the oil flows through the shell at a rate of 0.2 kg/s. the water and the oil enter at temperatures 18°c and 160°c, respectively. determine the rate of heat transfer in the heat exchanger and the outlet temperatures of the water and the oil. answers: 36.2 kw, 104.6°c, 77.7°c

Which of the following represents an upright image? a. -do b. +m c. -m d. +do

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 ..

Students design a model roller-coaster track. they place a rubber ball at the highest point on the track and let it go. the ball rolls along the track pulled only by the force of gravity. eventually, it comes to a stop. which change to the design will result in the ball moving the greatest distance?