Question 221153: A projectile is thrown upward at the rate of 42 feet per second from a platform 150 feet high. How long does it take to hit ground? Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website! A projectile is thrown upward at the rate of 42 feet per second from a platform 150 feet high. How long does it take to hit ground?
-------------------------
s(t) = -16t^2+vot+ho
s(t) = 0 when the object hits the ground
-16t^2 + 42t + 150 = 0
---
Quadratic Formula:
t = [-42 +- sqrt(42^2-4*-16*150)]/(-32)
----
t = [-42 +- sqrt(11364)]/-32
---
Positive solution:
t = [-42-106.6]/-32
---
t = 4.644 seconds
===============================
Cheers,
Stan H.
(