Answer:
7.0 m/s
Step-by-step explanation:
The question is on Free-Fall
In a free fall, an object falls freely without only gravity acting on it. Velocity at the top is zero m/s
Height of fall, h=1/2gt²
Velocity, v=gt where g is gravity acceleration=9.8m/s² and t is time taken fall the fall
Finding the t taken for the fall;
h=2.5m but we know h=1/2gt²⇒substitute values in this equation
2.5=1/2×g×t²
2.5=1/2×9.8×t²⇒2.5=4.9t²
make t subject of the equation;
t²=2.5/4.9
t=√2.5/4.9 =0.7143sec
Finding the velocity
v=gt
v=9.8×0.7143=7m/s