Respuesta :
Answer:
After 14.92 seconds, the arrow hits the ground.
Step-by-step explanation:
Given:
Initial velocity of the arrow is, [tex]u=240\ ft/s or 73.152\ m/s[/tex]
The arrow goes up and come back to the same starting position. So, initial position is same as that of final position.
Therefore, displacement of the arrow is 0 m.
The displacement of the arrow is given as:
[tex]s=ut-\frac{1}{2}gt^{2}[/tex] (equation 1)
Plug all value in equation 1 and solve for [tex]t[/tex]
[tex]0=73.152\timests t-\frac{1}{2} \times9.8 \times t^{2}[/tex]
[tex]0=73.152\timests t-4.9 \times t^{2}[/tex]
[tex]0=t(73.152-4.9 \times t)[/tex]
[tex]73.152-4.9\times t=0[/tex] where [tex]t\neq 0[/tex]
[tex]4.9\times t=73.152[/tex]
[tex]t=\frac{73.152}{4.9}= 14.92\ s[/tex]
∴ After 14.92 seconds, the arrow hits the ground.
