+0  
 
0
29
1
avatar

The height (in meters) of a shot cannonball follows a trajectory given by $h(t) = -4.9t^2 + 14t - 0.4$ at time t (in seconds). As an improper fraction, for how long is the cannonball at or above a height of 6 meters?

 Feb 23, 2019
 #1
avatar+17253 
+1

Set h >=6   and solve for t

 

6>= -4.9 t^2 + 14 t - 0.4

0 >= -4.9 t^2 + 14 t - 6.4     Use Quadratic Formula or graphing to find   t = .5714  and   2.286  sec

So between    (.5714, 2.286)    the cannonball is = to or higher than 6 m

 Feb 23, 2019

27 Online Users

avatar