Answer:
C. The floor pushing back against the foot
Explanation:
Anything that's dropped on or near the Earth accelerates at the rate of
9.8 m/s² on its way down. The mass of the object makes no difference.
After falling for 2 seconds, it's falling at the rate of 19.6 m/s.
Momentum = (mass) x (speed)
The egg's momentum is (5.07 kg) x (19.6 m/s) = 99.4 kg-m/s .
Explanation:
We will calculate the gravitational potential energy as follows.

= 
= 1164000 J
or, = 1164 kJ (as 1 kJ = 1000 J)
Now, we will calculate the change in potential energy as follows.

=
= 
= -873000 J
or, = -873 kJ
Thus, we can conclude that change in gravitational potential energy is -873 kJ.