Afirecracker shoots up from a hill 140 feet high, with an initial speed of 100 feet per sound. using the formula h(t) = -16t2 + be + s, approximately how long will it take the firecracker to hit the ground? a.) 5 secs b.) 7 secsc.) 9 secsd.) 11 secs

Most likely C it would take 9 secs.

- "runner b is moving at a slower rate."

- "the graphs shown are graphs of distance(km) against time(min).

the slopes of this graphs are are given by:

slope = (change in y)/(change in x)

= (change in distance)/(change in time)

this is the formula for finding the speed. so, the slope of these graphs represent the speed of the runner.

taking each division in the graph to represent 1 on both axis:

runner a ⇒ speed = (2-0)/(1-0)

= 2/1

= 2 km/min

runner b ⇒ speed = (3-0)/(3-0)

= 3/3

= 1 km/min

this shows that   runner b is moving at a slower rate."