Question

The sky diver was free falling for how many seconds?

Answer 1

Given

`s(t)=16t^2`

Since the skydiver fell 4800ft, we need to set s(t)=4800 and solve for t, as shown below

`\begin{gathered} s(t)=4800 \\ \Rightarrow16t^2=4800 \end{gathered}`

Solve for t, as follows,

`\begin{gathered} \Rightarrow t^2=(4800)/(16)=300 \\ \Rightarrow t=\pm√(300)=\pm√(100*3)=\pm10√(3) \\ \Rightarrow t=\pm10√(3) \end{gathered}`

However, a negative time would indicate that the skydiver was falling before jumping from the plane, which is impossible.

Therefore, the only valid answer is 10sqrt(3).

The answer is 10sqrt(3)