Final answer:
Your backpack will appear to be its actual weight of 40 N.the backpack will feel as heavy as its actual weight, which is 40 N. The perception of weight changes only when there's an acceleration, either upward or downward. In such cases, the apparent weight may differ due to the net force acting on the object.
Explanation:
When riding in an elevator moving at a constant speed, as in this scenario, there's no change in the apparent weight of objects. This is because there is no acceleration experienced by the rider.
According to Newton's first law of motion, objects at rest or moving at a constant speed will remain at that state unless acted upon by an external force. In this case, since the elevator is moving at a constant speed without any change in velocity (acceleration), there's no additional force acting on the backpack or the person carrying it.
Therefore, the backpack will feel as heavy as its actual weight, which is 40 N. The perception of weight changes only when there's an acceleration, either upward or downward. In such cases, the apparent weight may differ due to the net force acting on the object.