Kickball!!!!!!!!!!

Question

A kickball is kicked upward with an initial vertical velocity of 3.2 meters per second. The height of the ball is given by

h=-9.8t^2+3.2t

where the height H is measured in meters, and the time T is measured in seconds. After how many seconds does the ball land??????

 

Answer 1

You want to know when the height H is equal to 0. This will happen twice - once at the start (when t=0) and later once the ball has landed. Either way, start by setting H=0. 

So     0 = -9.8t^2 + 3.2t

GCF   0 = t (-9.8t + 3.2) 

t = 0        OR         -9.8t + 3.2 = 0... Subtract 3.2 from both sides here.... -9.8t = -3.2... so t = .33 seconds

The ball lands after .33 seconds