Question 154065
 you have thrown a baseball straight upward from a height of about 6 feet. A friend has used a stop watch to record the time the ball is in the air. If it takes approximately 6.5 seconds before the ball strikes the ground, explain how you can find the ball's initial velocity.
;
Using the equation -16t^2 + vt + c = h
Where:
h = height of the ball at t sec
t = time in seconds
v = velocity (upward)
-16t^2 = gravity (downward)
c = initial height
:
In this problem t = 6.5 sec.  c = 6 ft; h = 0 (ground)
:
-16(6.5^2) + 6.5v + 6 = 0
:
-16(42.25) + 6.5v + 6 = 0
:
-676 + 6.5v + 6 = 0
:
6.5v - 670 = 0
v = {{{((670))/6.5}}}
v = 103.1 ft/sec is the velocity