3) An airliner has altitude h. Also, let t be time. If the rate of change of the airliner's altitude with
Ah
ft
respect to time is
-=-1500- how long
At
min
does it take the airliner to descend from
h = 32,000 ft to ground level (h = 0)?
A) 17.79 min
B) 18.60 min
C) 19.51 min
D) 20.42 min
E) 21.33 min

For every corresponding pair of cross sections, the area of the cross section of a sphere with radius r is equal to the area of the cross section of a cylinder with radius and height 2r minus the volume of two cones, each with a radius and height of r. a cross section of the sphere is and a cross section of the cylinder minus the cones, taken parallel to the base of cylinder, is the volume of the cylinder with radius r and height 2r is and the volume of each cone with radius r and height r is 1/3 pie r^3. so the volume of the cylinder minus the two cones is therefore, the volume of the cylinder is 4/3pie r^3 by cavalieri's principle. (fill in options are: r/2- r- 2r- an annulus- a circle -1/3pier^3- 2/3pier^3- 4/3pier^3- 5/3pier^3- 2pier^3- 4pier^3)