I would say friction because it requires to surfaces in order for the force to take place
correct me if I'm wrong.
Answer:
14 m/s
Explanation:
The motion of the stone is a free fall motion, so an accelerated motion with constant acceleration g = 9.8 m/s^2 towards the ground. So, we can use the following SUVAT equation:

where
v is the final speed of the stone as it reaches the water
u = 0 is the initial speed
g = 9.8 m/s^2 is the acceleration
h = 10 m is the distance covered by the stone
Solving for v, we find

The answer given by E2020 is
"The padding around the goal post increases the time of the collision between the player and the post, which decreases the force exerted to bring the player to a stop"
Answer:
U2 = KAε0V2 / (2d)
Explanation:
The dielectric constant K just replaces the "3″ from Part B.
12N because you are just adding those two up on the same side