Answer:
vf = 7 m/s
Explanation:
The final velocity of the ball right before it hits the ground can be found by using the third equation of motion:
[tex]2gh = v_f^2 - v_i^2[/tex]
where,
g = acceleration due to gravity = 9.81 m/s²
h = height = 2.5 m
vf = final velocity = ?
vi = initial velocity = 0 m/s
Therefore,
[tex]2(9.81\ m/s^2)(2.5\ m) = v_f^2 - (0\ m/s)^2\\v_f = \sqrt{49.05\ m^2/s^2}\\[/tex]
vf = 7 m/s
