Question

Mr. Alim's science class launched a toy rocket from ground level with an initial upward velocity of 60 feet per second. The height h of the rocket in feet above the ground after t seconds is modeled by the equation h = 60t – 16t?. How long was the rocket in the air before it returned to the ground?

Answer 1

Given,

The initial velocity of the rocket is 60 feet per second.

The model for the height of the rocket after t seconds is,

`h=60t-16t^2`

When the rocket returns to the gorund, its height becomes 0.

Taking the equation of height when the rocket returns to the gorund,

`\begin{gathered} 60t-16t^2=0 \\ (15-4t)=0 \\ \text{15-4t=0} \\ \text{t=}(15)/(4) \\ t=3.75 \end{gathered}`

Hence, the rocket in the air before it return to the ground for 3.75 seconds.