Question

the equation h(t)=−9.8t² + 100 represents the relationship of the height, in meters, over time, in seconds, of an object dropped from the height of 100 meters. what is the height of the object 2.5 seconds after it was dropped? (1 point)
138.75 meters
3.19 meters
100 meters
38.75 meters

Explanation:

Step1: Substitute time value

Substitute $t = 2.5$ into $h(t)=-9.8t^{2}+100$.
$h(2.5)=-9.8\times(2.5)^{2}+100$

Step2: Calculate square term

$(2.5)^{2}=6.25$, so $h(2.5)=-9.8\times6.25 + 100$.

Step3: Calculate multiplication

$-9.8\times6.25=-61.25$, then $h(2.5)=-61.25 + 100$.

Step4: Calculate sum

$h(2.5)=38.75$.

Answer:

38.75 meters