During a practice match, a softball pitcher throws a ball whose height can be modeled by the equation h=−16t2+24t+1, where h = height in feet and t = time in seconds. How long does it take for the ball to reach a height of 6 feet?
0.25 and 1.25 secs
Given Height = 6
⇒−16t2+24t+1=6
⇒16t2−24t+5=0
⇒16t2−4t−20t+5=0
⇒16t2−4t−20t+5=0
⇒4t(4t−1)−5(4t−1)=0
⇒(4t−1)(4t−5)=0
t=14,54 or 0.25, 1.25
So, at time 0.25 secs and 1.25 secs, the ball will be at a height of 6 feet.