Get detailed and reliable answers to your questions with IDNLearn.com. Our community is here to provide the comprehensive and accurate answers you need to make informed decisions.

The height of an object dropped from a hot-air balloon can be determined by the formula h-161² +s, where h is the height of the object in feet, t is the elapsed time in seconds, and s is the height of the balloon. If the balloon is 400 feet from the ground, how long will it take for an object dropped from the balloon to hit the ground? ●2.5 seconds ●5 seconds ●7.5 seconds ● 10 seconds

Sagot :

To find the time that it will take for an object to hit the ground, consider that the ground has a height of 0.

Since the balloon is 400 feet from the ground and the heigh of the ground is h=0, substitute s=400 and h=0 into the equation and solve for t:

[tex]\begin{gathered} h=-16t^2+s \\ \Rightarrow0=-16t^2+400 \\ \Rightarrow16t^2=400 \\ \Rightarrow t^2=\frac{400}{16} \\ \Rightarrow t^2=25 \\ \Rightarrow t=\sqrt[]{25} \\ \Rightarrow t=5 \end{gathered}[/tex]

Therefore, it would take 5 seconds for the object to hit the ground.