A=g
v=⌠g dt
v=gt+C, where C=v initial
v=gt+vi
h=⌠v dt
h=gt^2/2+vit+C, where C=h initial
h=gt^2/2+vit+hi
We are told that vi=42 ft/s, hi=0, and we know g≈-32 ft/s^2 so
h(t)=-16t^2+42t
The ball will hit the ground when h=0 so
-16t^2+42t=0
-2t(8t-21)=0, since t>0
8t-21=0
8t=21
t=21/8
t=2.625 sec
t≈2.6 sec (to nearest tenth of a second)
Its B. I cam tell by looking.
The graph forms a straight line going downwards. The straight line means that the speed is constant. It is going downwards meaning it is stopping.
The best statement that represents the graph is:
<span>Each point shows the remaining distance, in feet, to the finish line of a race t seconds after a runner begins the final stretch and runs at a constant speed.</span>
