SOLUTION: When a skydiver jumps from an airplane, her downward velocity, in feet per second, before she opens her parachute is given by the formula below, where t is the number of seconds th

Algebra ->  Systems-of-equations -> SOLUTION: When a skydiver jumps from an airplane, her downward velocity, in feet per second, before she opens her parachute is given by the formula below, where t is the number of seconds th      Log On


   

Question 1002200: When a skydiver jumps from an airplane, her downward velocity, in feet per second, before she opens her parachute is given by the formula below, where t is the number of seconds that have elapsed since she jumped from the airplane. The terminal velocity for the skydiver is 174 feet per second.

v = 174(1 - 0.834t)
How long does it take to reach 75% of the terminal velocity? (Round your answer to two decimal places.)
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!

"The terminal velocity for the skydiver is 174 feet per second" and it asks "How long does it take to reach 75% of the terminal velocity?"
0.75*174 = 130.5
So they want to know when the velocity will be 130.5 ft/s



v = 174*(1 - 0.834t)
130.5 = 174*(1 - 0.834t) .... plug in v = 130.5; solve for t
130.5 = 174*1 + 174*(-0.834t)
130.5 = 174 - 145.116t
130.5 - 174 = -145.116t
-43.5 = -145.116t
-43.5/(-145.116) = t
0.29976019184652 = t
t = 0.29976019184652
t = 0.30 ... round to 2 decimal places


So the approximate answer is t = 0.30
It will take approximately 0.30 seconds for the velocity to be 75% of terminal velocity