1) A rock is thrown downward from the top of a 40.0-m-tall tower with an initial speed of 12 m/s. Assuming
negligible air resistance, what is the speed of the rock just before hitting the ground?

Respuesta :

army27

Answer:

12m/s

Explanation:

without air resistance the speed is constant

Answer:

By using [tex]v^{2}_{f} = v^{2}_{i} + 2a\Delta y[/tex], with [tex]v_{i} = -12m/s[/tex] and [tex]\Delta y = -40m[/tex]:

[tex]v^{2}_{f} = v^{2}_{i} + 2a/Delta y[/tex]

[tex]v^{2} = (-12m/s)^{2} + 2(-9.80m/s^{2})(-40m)[/tex]

[tex]v = -30m/s[/tex]

Explanation:

Hope this helped!