Question

An airplane flying at an altitude of 32,000 feet descends at a rate of 1,300 feet per minute. If the plane
descends for 15 minutes, what would its altitude be in feet?

Answer 1

if the angle of descending is not given then:

first u need to find the distance traveled during the 15min. to do so:
v=d/t so d=v.t=(1300ft/min).15min=19500ft.
but initially the plane is at 32000ft altitude, from there it travelled 19500ft, so the altitude(relative to ground position,0,) of the final position is 32000-19500=12500ft
as illustrated in drawing
hope that helps