When light with a frequency fi = 547.5 thz illuminates a metal surface, the most energetic photoelectrons have 1.260 x 10-19 j of kinetic energy. when light with a frequency fo = 738.8 thz is used instead, the most energetic photo-electrons have 2.480 x 10-19 j of kinetic energy. using these experimental results, determine (a) the approximate value of planck's constant. h = jos (b) the work function for this metal. ~ (hint for part (b): use the two-point formula that you learned in algebra: y-yı = *=*(x - 1)

Which units can be used to measure length or distance? check all that apply. gram meter kilometer liter inch

Na food processing facility, a spherical container of inner radius r1 5 40 cm, outer radius r2 5 41 cm, and ther- mal conductivity k 5 1.5 w/m · k is used to store hot water and to keep it at 100°c at all times. to accomplish this, the outer surface of the container is wrapped with a 800-w electric strip heater and then insulated. the temperature of the inner surface of the container is observed to be nearly 120°c at all times. as- suming 10 percent of the heat generated in the heater is lost through the insulation, (a) express the differential equation and the boundary conditions for steady one-dimensional heat conduction through the container, (b) obtain a relation for the variation of temperature in the container material by solving the differential equation, and (c) evaluate the outer surface tempera- ture of the container. also determine how much water at 100°c this tank can supply steadily if the cold water enters at 20°c.

Ahanging spring stretches by 35.0 cm when an object of mass 450 g is hung on it at rest. in this situation, we define its position as x = 0. the object is pulled down an additional 18.0 cm and released from rest to oscillate without friction. what is its position x at a moment 84.4 s later? express your answer in cm.