Question

Dan uses a remote control to make his drone take off from the ground. Function h represents the height, in feet, of the drone t seconds after it begins flying.

h(t)= -16(t-2)^2+64

Which statement correctly describes this situation?

A.
The drone is on the ground at 0 and 2 seconds.
B.
The drone is on the ground at 0 and 16 seconds.
C.
The drone is on the ground at 0 and 4 seconds.
D.
The drone is on the ground at 2 and 4 seconds.

Answer 1

Answer: C.   The drone is on the ground at 0 and 4 seconds.

Step-by-step explanation:

Here the function that shows the height of the drone,

$h(t) = -16(t-2)^2+64$

Where t is the time in seconds.

Since, the drone is ground when, h(t) = 0

$-16(t-2)^2+64=0$

$-16(t-2)^2 = -64$   (by subtracting 64 from both sides 64)

$(t-2)^2 = 4$           (dividing both sides by -16 )

$t^2-4t+4= 4$        

$t^2-4t= 0$             (by subtracting 4 from both sides)

$t(t-4)= 0$      

⇒ t = 0 or t = 4  

Thus, Option C is correct.

Answer 2

Answer:

The drone is on the ground at 0 and 4 seconds.

Step-by-step explanation:

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