The distance covered by the acorn is 3.136 m.
<u>Explanation:</u>
The time taken for the acorn to hit the ground is 0.8 s. As it is a free fall, the acorn will be completely under the influence of gravity. So the acceleration will be acceleration due to gravity.
Then using the second law of equation,

Since the initial velocity and time is zero, then the time taken to reach the ground is stated as 0.8 s, so

So the distance covered by the acorn is 3.136 m.
F = ma
We have mass = 0.2kg
and acceleration = 20 m/s^2
So..
F = (0.2)(20)
F = 4 N
Potential if it is off or kinetic energy when its on
Answer:
Answer is C
Explanation:
Let's say the pendulum starts swinging from its max height from the left. It then will go down and reach the equilibrium position, this will make it lose GPE while gaining KE (the loss in GPE = gain in KE). At the equilibrium position it has the max KE (max velocity) and minimum GPE. After passing the equilibrium it then starts to head up to the max height on the right, the pendulum gains GPE while losing KE and at the top will have minimum KE while having max GPE. Meaning throughout its joruney the total energy remains constant as
Total energy = KE + GPE
I have attached a simple diagram below, the y axis is the energy and x axis being the time (where t = 0 is the pendulum starting from max height left of the equilibrium). The green curve the the GPE and blue curve is KE. Red line shows that at all times the energy is constant.