Safety engineers estimate that an elevator can hold 20 persons of 75kg average mass. The elevator itself has a mass of 500kg. Tensile strength test how the cable supporting the elevator can tolerate a maximum force of 2.96X10^4N. What is the greatest acceleration that the elevators motor can produce without breaking the cable? (show work)

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.

The field between two charged parallel plates is kept constant. if the two plates are brought closer together, the potential difference between the two plates either a) decrease b) does not change c) increase?

Which of these has some mechanical energy? a. an atom b. heat inside earth c. a book on a shelf d. the fire from a lit match