Your kid sister is making a mobile representing the earth, moon, and sun for her grade schoolscience fair. The ruler is provided below to help you determine positions of the three hangingballs, of mass 15 g, 5 g, and 30 g, respectively. Of the five options provided, where is thehorizontal center of mass at which would youconnect a string to this mobile so that it wouldremain balanced when you hung it from the string?(The rods and strings all have negligiblemass compared to the balls.)

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.

If a stone with an original velocity of 0 is falling from a ledgeand takes 8 seconds to hoybthe ground whays the final velocity of the stone

Which describes increasing the efficiency of energy resource