Respuesta :
ANSWER:
The initial velocity where the keys thrown is 9.59 m/s
The velocity of the keys just before they were caught is -4.62 m/s
STEP-BY-STEP EXPLANATION:
Given:
Height (h) = 3.6 m
Time (t) = 1.45 sec
We can calculate the initial velocity using the following formula:
[tex]h=ut+\frac{1}{2}at^2[/tex]We replace and solve for u (initial velocity)
[tex]\begin{gathered} 3.6=u\cdot1.45+\frac{1}{2}\cdot(-9.8)\cdot(1.45)^2 \\ \\ 3.6=1.45u-10.3 \\ \\ 1.45u=3.6+10.3 \\ \\ u=\frac{13.9}{1.45} \\ \\ u=9.59\text{ m/s} \end{gathered}[/tex]So, the initial velocity where the keys thrown is 9.59 m/s
Now, we calculate the final velocity using the following formula:
[tex]\begin{gathered} v=u+at \\ \\ \text{ we replacing} \\ \\ v=9.59+(-9.8)(1.45) \\ \\ v=9.59-14.21 \\ \\ v=-4.62\text{ m/s} \end{gathered}[/tex]Therefore, the velocity of the keys just before they were caught is -4.62 m/s
