The answer is 0.74 J.
The potential energy of the object is its stored energy. Gravitational potential energy is the stored energy of the object as the result of its height can be expressed as:
E = m · g · h
where
E - the potential energy of the object,
m - the mass of the object,
g - gravitational acceleration (g = 9.81 m/s²),
h - the height of the object.
It is given:
g = 9.81 m/s²
m = 0.03 kg
h = 2.5 m
Therefore:
E = m · g · h
⇒ E = 0.03 kg · 9.81 m/s² · 2.5 m
⇒ E = 0.03 · 9.81 · 2.5 kg ·m/s² · m
⇒ E = 0.74 kg ·m²/s²
⇒ E = 0.74 J
Therefore, the potential energy of the acorn is 0.74 J.