Answer:
The change in gravitational potential energy from point A to point B can be calculated using the formula:
ΔU = mgh
Where:
m = mass of the pendulum = 1.5 kg
g = acceleration due to gravity = 9.8 m/s^2
h = change in height = yB - yA = 0.12 m - 0.04 m = 0.08 m
So, the change in gravitational potential energy from A to B is:
ΔU = (1.5 kg)(9.8 m/s^2)(0.08 m) = 1.176 J
So, the change in gravitational potential energy from A to B is 1.176 Joules.