$$v = u + at$$
where:
* $$v$$ is the final velocity (39.2 m/s down)
* $$u$$ is the initial velocity (0 m/s, since the brick starts from rest)
* $$a$$ is the acceleration due to gravity (-9.8 m/s²)
* $$t$$ is the time taken
Substituting the given values, we get:
$$39.2 = 0 + (-9.8)t$$
Solving for $$t$$, we get:
$$t = \frac{39.2}{9.8} = 4 seconds$$
Therefore, the brick falls for 4 seconds before striking the ground.
