They will hit the ground at the same time, as mass is negligible when calculating the acceleration of gravity when there is no air resistance
There is a threshold frequency for each metal, and only light of a frequency higher than this threshold causes electrons to be emitted from the metal surface.
During the falling down, two forces are present: gravitational force and air resistance.
So, the net force = mg - f = 12*9.8 - 27 = 90.6 N, the positive sign indicates the direction is pointing towards the center of the earth, which is the same as gravitational force
Kinetic energy is the energy associated with the motion of an object. It's a scalar quantity, there is no direction associated with KE and it has no components.

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Therefore Kinetic energy is 817.96J.