Question

A rocket is launched from the ground. The quadratic function y=-16x2+56x models the rockets height in feet above the ground after x seconds. About how long is the rocket in the air

Answer 1

Answer:

Therefore,

3.5 s long was the rocket in the air.

Step-by-step explanation:

Given:

A rocket is launched from the ground.

Height function for Rocket is given as

$y=-16x^{2}+56x$

Where,

y = height in function with x as time in second

To Find:

How long is the rocket in the air, x =?

Solution:

Expression is given

$y=-16x^{2}+56x$

So for time in air put y = 0 in above Expression

$0=-16x^{2}+56x$

$16x^{2}-56x=0\\16x(x-3.5)=0\\16x=0\ or\ x-3.5 = 0\\x=0\ or\ x= 3.5$

x cannot be negative

∴ x = 3.5 sec.

Therefore,

3.5 s long was the rocket in the air.