Answer :
Final answer:
The tension in the cable holding a stationary or constantly moving elevator must equal the weight of the elevator, which in this case is 3000 lbs, so the correct answer is (b) exactly 3000 lbs.
Explanation:
The student's question is about an elevator weighing 3000 lbs and asks if the cable supporting it would weigh less than, exactly, or more than 3000 lbs. However, the provided examples and information do not directly address the weight of the elevator cable itself but rather discuss the forces involved in elevator movement and cable strength regarding a decorative light fixture in an elevator.
The force a cable must exert to hold an elevator at rest is equal to the weight of the elevator due to Newton's first law, which states that an object at rest will remain at rest unless acted on by an unbalanced force. Therefore, if the elevator is at rest or moving at a constant velocity, the tension in the cable must be equal to the weight of the elevator (3000 lbs in this case) to counteract the force of gravity.
