-- 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.
Answer:
Part a)

Part b)

Explanation:
As we know that the see saw bar is massless so here torque due to two masses is given as

here we will have

now we will have inertia of two masses given as

now we have

now the angular acceleration is given as

so we have

Part b)
Now if the rod is not massles then we will have total inertia given as

so we will have

now the acceleration is given as


D.) Rubbing your hands together
Hope this helps! ( brainleist??)