contestada

If an object is dropped from a height of 55 feet, the function d=-16t^2+55 gives the height of the object after t seconds. Graph this function. Approximately how long does it take the object to reach the ground (d=0)?

Respuesta :

to find the time to reach ground solve -16t^2 +55 = 0

t^2 = 55/16
t = sqrt55 / 4 = 1.85 seconds

Answer:

Approximately 1.85 sec does it take the object to reach the ground

Step-by-step explanation:

As per the statement:

If an object is dropped from a height of 55 feet

⇒[tex]h_0 = 55[/tex] ft

The function is given by:

[tex]d = -16t^2+55[/tex]   .....[1] gives the height of the object after t seconds.

We make the table for some values of t.

t                    d

0                  55

1                  39

2                 -9

3                 -89

4                -201

Plot these points on the coordinate plane.

You can see the graph as shown below.

Now, find how long does it take the object to reach the ground (d=0).

Substitute d = 0  in [1] we have;

[tex]0 = -16t^2+55[/tex]

⇒[tex]16t^2 = 55[/tex]

Divide both sides by 16 we get;

[tex]t^2 = 3.4375[/tex]

[tex]t =\pm \sqrt{3.4375}[/tex]

Since, t cannot be in negative.

⇒[tex]t = 1.85404962[/tex] second.

Therefore, Approximately 1.85 sec does it take the object to reach the ground

Ver imagen OrethaWilkison