An object is launched directly in the air at a speed of 64 feet per second from a platform located 16 feet in the air. The motion of the object can be modeled using the function f(t)=−16t2+64t+16, where t is the time in seconds and f(t) is the height of the object. When, in seconds, will the object reach its maximum height? Do not include units in your answer.

Respuesta :

Answer:

After 2 seconds the object reach its maximum height of 80 feet.

Step-by-step explanation:

Consider the provided function.

[tex]f(t)=-16t^2+64t+16[/tex]

The function is a downward parabola.

The object will reach its max height at the vertex of the parabola.

The vertex of the parabola is given by [tex](\frac{-b}{2a}, f(\frac{-b}{2a}))[/tex],

Where the standard form is [tex]f=at^2+bt+c[/tex].

By comparing the provided function with the standard form.

a=-16, b=64 and c=16

Thus, the vertex are:

[tex]t=\frac{-b}{2a}[/tex]

[tex]t=\frac{-64}{2(-16)}=\frac{64}{32}[/tex]

[tex]t=2[/tex]

Now substitute the value of t in the provided function.

[tex]f(t)=-16(2)^2+64(2)+16[/tex]

[tex]f(t)=-16(4)+128+16[/tex]

[tex]f(t)=-64+144[/tex]

[tex]f(t)=80[/tex]

Hence, after 2 seconds the object reach its maximum height of 80 feet.

Answer:

2 seconds

Step-by-step explanation:

When the object reaches its highest point is the t-value of the turning point. Thus we need to find the where maximum quadratic function

−16t2+64t+16

occurs.

We know that the maximum (or minimum) of a parabola is reached at x=−b2a=−642(−16)=2, showing that the object will reach its highest point at 2 seconds.