Question

The loss of potential energy of an elevator coming down from the top of the building to a stop at the ground floor is:

• A. lost to the driving motors
• B. converted into heat
• C. lost in friction of moving surfaces
• D. used up in lifting up counter weight

Hint:

In elevator systems, the counterweight helps to reduce the amount of energy needed by the motor by balancing the elevator’s weight. Understanding this system is key to understanding how energy is efficiently transferred.

Answer 1

The Correct Option is D

Step 1: Understanding the Energy Transfer When the elevator descends, its potential energy decreases as it moves toward the ground. This loss in potential energy needs to be accounted for by other forms of energy.
Step 2: Role of the Counterweight In an elevator system, a counterweight is typically used to balance the weight of the elevator. When the elevator moves down, its potential energy is transferred to the counterweight, which moves in the opposite direction (upward). This mechanism helps to offset the work that needs to be done by the motor and reduces the overall energy required.
Step 3: Energy Conversion Process The potential energy lost by the descending elevator is primarily used to lift the counterweight. This process helps to maintain a balanced system, so energy is not wasted to friction or heat.
Step 4: Conclusion Thus, the correct answer is that the lost potential energy is used to lift the counterweight.