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A rock is dropped from a height of 100 feet. Calculate the time between when the rock was dropped and when it landed. If we choose "down" as positive and ignore air friction, the
function is h(t) = 16t^2 – 100.

A)t = 2.5 seconds

B)t = 6.25 seconds

C)t = 10 seconds

D)t = 12.5

A rock is dropped from a height of 100 feet Calculate the time between when the rock was dropped and when it landed If we choose down as positive and ignore air class=

Respuesta :

reinhard10158

Answer:

A

Step-by-step explanation:

the rock lands when it reaches height 0.

so, for what t is h(t) = 0 ?

16t² - 100 = 0

16t² = 100

now we pull the square root on both sides (we can ignore the negative solutions, as negative seconds don't make any sense in our scenario)

4t = 10

t = 10/4 = 5/2 = 2.5 seconds

so, A is correct.

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