Answer:
a)
, b) 
Explanation:
a) The potential energy is:



b) Maximum final speed:

The final speed is:


That would be 0 degrees Celsius aka the melting point of water.... If you look at the diagram I attached you notice that at 0 degrees Celsius it is flat, this is because much heat is needed at this point for water to rise to 1 degree... It is the same for the boiling point (100)
Hope this helps! (If correct, please rank as brainliest answer) :)
F = force applied to lift the box = weight of the box = 88 N
P = power produced while lifting the box upward = 72 Watt
v = speed of the box = ?
Speed of the box is given as
v = 
inserting the values
v = 
v = 0.82 ms⁻¹