Final answer:
When you lift a person who is lifting an object, you are lifting the combined weight of both the person and the object.
Step-by-step explanation:
When you lift a person who is lifting an object, you are essentially lifting the combined weight of both the person and the object. The force required to lift them depends on the weights of both the person and the object. For example, if the person weighs 70 kg and the object weighs 30 kg, you would be lifting 100 kg in total.
This can be understood using Newton's third law of motion, which states that for every action, there is an equal and opposite reaction. When you exert a force to lift the person, they exert an equal and opposite force downwards due to their weight, which adds to the force required to lift the object.
Therefore, when you lift a person who is already lifting an object, you are lifting up the combined weight of both the person and the object.