Answer:
7.0 m/s
Step-by-step explanation:
We can solve this using the 2 kinematic equations and you can use either:
[tex]Vf=Vi+at\\\\vf^{2}=vi^{2}+2ad[/tex]
So let's use the first one.
Vi = initial velocity
Vf = final velocity
a = acceleration due to gravity (constant 9.8m/s²)
t = time
The marble is dropped so this means that it is in free fall. The initial velocity is always 0m/s.
We are given then the following:
d = 2.5m
t = 0.71s
Vi = 0 m/s
a = 9.8m/s²
So we plug in the values we know and solve:
[tex]Vf = Vi + at\\\\Vf = 0 m/s + (9.8m/s^{2})(0.71s)\\Vf = 6.958m/s \cong 7.0m/s[/tex]