Explanation:
A worker picks up the bag of gravel. We need to find the speed of the bucket after it has descended 2.30 m from rest. It is case of conservation of energy. So,

h = 2.3 m

So, the speed of the bucket after it has descended 2.30 m from rest is 6.71 m/s.
The rate of flow of electric CHARGE past any point is described in the unit of electric CURRENT ... the Ampere.
In physics, work is defined as the total energy when an object is moved to a certain displacement by the application of external force. It is calculated by the expression W = Fd. For this case, the displacement is apparently zero, then there is no work in the system above.