Answer:
2. at the lowest point
Explanation:
The motion of the pendulum is a continuous conversion between kinetic energy (KE) and gravitational potential energy (GPE). This is because the mechanical energy of the pendulum, which is sum of KE and GPE, is constant:
E = KE + GPE = const.
Therefore, when KE is maximum, GPE is minimum, and viceversa.
So, the point of the motion where the KE is maximum is where the GPE is minimum: and since the GPE is directly proportional to the heigth of the bob:

we see that GPE is minimum when the bob is at the lowest point,so the correct answer is
2. at the lowest point
Answer: 
Explanation:
Given
Length of beam 
mass of beam 
Two forces of equal intensity acted in the opposite direction, therefore, they create a torque of magnitude

Also, the beam starts rotating about its center
So, the moment of inertia of the beam is

Torque is the product of moment of inertia and angular acceleration

Answer:
the air has to be unstable as well as it needs to be moved upwards.
Explanation:
it needs to be moved upwards and also needs to have unstable air.
Statements 1, 3, and 5 are true.
(A, C, and E)
Gpe is basses on the force equation...
GPE=m*g*h=1.5kg*9.8m/s^2*8m=117.6 N*m