Answer:
-76.44 J
Step-by-step explanation:
The force due to gravity is conservative, it means that no matter the path, the work done from A to B will be always the same and it depends on the vertical distance between A and B which in this case is 2.0 m.
So, the work done by the gravity is
W = Fdcosθ
Where the force is the weight so, F = mg = (3.9 kg)(9.8 m/s²) = 38.22 N
d is the vertical distance, so , d = 2.0 m
And θ is the angle between the displacement and the weight, so, θ = 180
Then,
W = (38.22N)(2.0 m)cos(180)
W = -76.44 J
Therefore, the work done by gravity along paths 1, 2, and 3 was -76.44 J