-- It takes the brick 8.9 seconds to reach the ground.
-- At the instant of the "splat", it's falling at 89 m/s.
-- The mass doesn't matter. If not for air resistance, every object
would fall at the same rate. The answer is the same for a feather,
a rubber chicken, a brick, or a school bus.
F=mg
if m doubled, F would double as well
Answer
D.Diffraction
Explanation
Diffraction is a property that is experienced by waves when they come across a barrier when they are in motion.
The ways tends to curve behind the barrier. This is called diffraction of waves.
Now, sound is a wave and it also experience diffraction. . So the brother will be able to hear the sound due to diffraction
