A sandbag is released from a hot air balloon that is 400ft above the ground. Using the falling object model, h = –16t2 + s, where h = height in feet, t = time in seconds, and s = initial height in feet, how long will it take for the sandbag to hit the ground?

A.
25 seconds
B.
4 seconds
C.
5 seconds
D.
20 seconds

Respuesta :

Answer:

It takes 5 seconds for the sandbag to hit the ground

Explanation:

Given:

Height at which the sand bag is released from the hot air balloon[tex]= -400 f t[/tex]

To find:

Time taken for the sandbag to hit the ground, t =?  

Solution:

The initial height =s

Initially the height will be 0

Hence[tex]s=0[/tex]

the falling object model equation  

[tex]h=-16 t^{2}+s[/tex]

Substituting the values we get,

[tex]h=-16 t^{2}+s[/tex]

[tex]400=16 t^{2}[/tex]

[tex]t^{2}=\frac{400}{16}[/tex]

[tex]t^{2}=25[/tex]

[tex]t=\sqrt{25}[/tex]

[tex]t=5 \text { seconds }[/tex]

Result:

Thus it takes 5 seconds for the sandbag to hit the ground