Answer with Step-by-step explanation:
We are given that height of projectile after t seconds is given by
a.h(t)=144 ft
t-3=0
t=3
After 3 s, the height of the project will be 144 feet in the air.
b.h(t)=0
At t=0, the initial position of projectile
At t=6 s , the projectile will hit the ground.