Question

A stuntwoman jumps from a building 73ft high and lands on an air bag that is 9ft tall. Her height above ground h in feet can be modeled by h (t) = 73 – 16 t^2, where t is the time in seconds.
a. How many seconds will the stuntwoman fall before touching the air bag? (Hint: Find the time t when the stuntwoman’s height above ground is 9 ft.)

Answer 1

Take the equation   h (t) = 73 – 16 t^2 and plugin 9 for h(t) and then solve for t like the following:

9 = 73 - 16 t^2
9 - 73 = 73-73 - 16t^2
-64 = -16t^2
-64 / -16 = -16t^2 / -16
4 = t^2
Now square both sides of 4 = t^2
$\sqrt{4} = \sqrt{t^2}$
2 = t
t = 2
Answer = 2 seconds