Answer:
work = 1125 [J]
Explanation:
To solve this problem we must remember the definition of power, which is defined as the relationship between work and time. The power can be calculated using the following equation:
Power = work/time
Power = 12.5 [w]
work = joules [J]
time = 1.5 [min] = 90 [s]
work = 12.5*90
work = 1125 [J]

Gravitational Potential Energy of an object is calculated by formula ~

where,
- m = mass of the object = 3500 kg
- g = Acceleration due to gravity = 12 m/s²
- h = height attained by the object = 4 m
Now, let's calculate its potential energy ~
The work you put into something is the energy it has afterward (neglecting friction and other so-called non-conservative forces). This is called the work-energy theorem. Think of objects in a gravitational field as "energy piggy banks". If you put X joules of energy into it, that energy will be there as potential energy, stored for later. So if you do 144J of work to elevate the bucket from an initial position, what ever it is initially, the final gravitational energy is 144J greater than before.