An airplane is flying at a constant speed in a positive direction. it slows down when it approaches the airport where it's going to land. which term describes the slowing of the plane?

a) stationary
b) positive velocity
c) positive acceleration
d) negative acceleration
e) constant velocity

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.

What is relative velocity? in which condition is relative velocity known by adding the velocity of the first body and that of the second body

The slope of a velocity time graph over any interval of time gives the during that interval