Question 123536
If there were no air resistance, then the height (in feet) above the earth for a skydiver t seconds after jumping from an airplane at 10,000 feet would be given by h(t)= -16t^2 + 10,000 

a) find the time that it would take to fall to earth with no air resistance: that is, find t for which (t)= 0.A skydiveractually gets about twice as much free fall time due to air resistance. 
When on earth the height is zero.
-16t^2+10,000=0
-16t^2 = -10,000
t^2 = 625
t = 25 seconds
----------------------------


b)Use the accompanying graph to determine whether the skydiver(with no air resistance ) falls farther in the first 5 seconds or the last 5 seconds of the fall. 
Height after 5 seconds = h(5)=-16(5^2)+10000 = 9600 ft
The skydiver falls 400 ft in the 1st 5 seconds.
------------------
Height after 20 seconds = h(20)=-16(20^2)+10000= 3600 ft
Height aftrer 25 seconds is zero
The skydiver falls 3600 ft in the last 5 seconds.
-----------------------
c) Is the skydiver's velocity increasing or decreasing as she falls?
increasing.
===============
Cheers,
Stan H.