214k views
1 vote
I need help with this question. Do I equal h(t) to 10 and then solve?

I need help with this question. Do I equal h(t) to 10 and then solve?-example-1
User Veblock
by
7.3k points

1 Answer

2 votes

incSolution:

Given that;


h(t)=-16t^2-10t+50

To fall 10 feet off of the ground,

Where


h(t)=10\text{ ft}

Substitute for h(t)


\begin{gathered} 10=-16t^2-10t+50 \\ -16t^2-10t+50=10 \\ -16t^2-10t+50-10=10-10 \\ -16t^2-10t+40=0 \end{gathered}

Applying quadratic formula


\begin{gathered} t=(-\left(-10\right)\pm√(\left(-10\right)^2-4\left(-16\right)\cdot\:40))/(2\left(-16\right)) \\ t=-(5+√(665))/(16),\:t=(√(665)-5)/(16) \\ t=-1.92422\text{ or }t=1.29922 \end{gathered}

Since, t can not be negative,

The time it will take is 1.30 seconds (nearest hundredth)

User Sternze
by
8.1k points