Question

the equation $h(t)= - 9.8t^{2}+100$ 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
100 meters
3.19 meters
38.75 meters

Explanation:

Step1: Substitute t value

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

Step2: Calculate $(2.5)^{2}$

$(2.5)^{2}=2.5\times2.5 = 6.25$
$h(2.5)=-9.8\times6.25 + 100$

Step3: Calculate $-9.8\times6.25$

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

Step4: Calculate the sum

$h(2.5)=38.75$

Answer:

38.75 meters