Final answer:
When lifting a bag of sugar, we consider the bag and the hand as the system. The free-body diagram should include the weight of the bag and the upward force exerted by the hand.
Step-by-step explanation:
When lifting a bag of sugar, the system under consideration is the bag and the hand. To draw a free-body diagram, we need to identify all the forces acting on the bag.
The main force is the weight of the bag, which can be labeled as Wb. This force is directed downwards and has a magnitude equal to the weight of the bag (–mg, where m is the mass of the bag and g is the acceleration due to gravity).
The hand exerts an upward force on the bag, which can be labeled as Fh. This force counteracts the weight of the bag and increases as the bag is lifted with increasing speed.
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