m = 7.0 kg, the mass of the groceries
h = 1.2 m, the elevation of the bag of groceries
The bag of groceries moves a constant velocity over the 2.7-m room.
At constant velocity, there is no applied force, and the kinetic energy remains constant.
At an elevation of 1.2 m, there is an increase in PE (potential energy) given by
V = m*g*h
= (7.0 kg)*(9.8 m/s²)*(1.2 m)
= 82.32 J
The change in PE is equal to the work done.
Answer: 82.3 J
