I believe the answer is stored energy.
Can i have more information?
Answer:
The acceleration of the object is -69.78 m/s²
Explanation:
Given;
postion of the particle:

The velocity of the particle is calculated as the change in the position of the particle with time;

Acceleration is the change in velocity with time;

The formula is:
Work = Force · Displacement
F = m · g
F = 16 kg · 9.8 m/s² = 156.8 N
and we know that:
d = 0.8 m
W = 156.8 N · 0.8 m = 125.44 J
Answer:
W = 125.44 J.