Assuming that the air resistance is neglectable, both bricks are only accelerated by gravity, which produces a constant acceleration on both bricks, which is the same, according Newton's 2nd Law, as we can see below:
⇒a = g = 9.8m/s² (pointing downward)
Since acceleration is constant, if both fall from the same height, we can apply the following kinematic equation:
Since both bricks are held off the edge, the initial speed is zero, so (2) reduces to the following equation:
Since h (the height of the balcony) is the same, we conclude that both bricks hit ground at exactly the same time.
If the air resistance is not negligible, due both bricks have zero initial speed, and have the same shape, they will be affected by the drag force in similar way, so they will reach the ground at approximately the same time.
