I):final velocity=initial velocity+acceleration due to gravity*time of travel
Therefore,
v=0+9.8*3.1
=30.38 m/s
If by floor you meant water bed then i think there isn't enough info in the question.
Answer: option A) initially increases, then decreases.
Justification:
The increase of the rate of effective collisions among particles as the temperature increases is explained by the collision theory in virtue of the increase of the kinetic energy.
This is, as the temperature increase so the kinetic energy increase and the higher the kinetic energy the greater the number of collisions and the greater the chances that this energy overcome the activation energy (the energy needed to start the reaction).
Now, as the reaction progress the number of reactants particles naturally decrease (some of them have been converted into product) so this lower number of particles means lower concentration which means lower collisions and, thereafter, a decrease in the reaction rate.
Answer:
it can occur in all waves because all wave have a frequency
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"
As waves get closer to the beach they increase in energy