Your goal is to maximize the rotational kinetic energy of the disc. For a fly wheel of
Question:
Your goal is to maximize the rotational kinetic energy of the disc. For a fly wheel of given geometry and the parameters of the dropping mass fixed, you are trying to maximize the angular speed of the fly wheel ω. Consider the following statements. In the fields below indicate if you agree with any of the engineers and explain your reasoning. If you disagree with a statement or any of its parts, provide an explicit explanation of where you think an engineer went wrong.
1) Engineer 1: We are dropping the hanging mass from the same height, therefore the total energy available to the system is always the same. If the available energy is the same then the fly wheel will spin up to the same angular speed regardless of the size of the pulley to which the weight is tied. To what method of approaching this problem does Engineer 1: refer?
1a) Explanation:
2) Engineer 2: The larger pulley provides larger torque for the same force from the falling mass. Larger torque will result in larger angular acceleration, therefore over the same distance through which the mass falls the fly wheel will have larger angular velocity. To what method of approaching this problem does Engineer 2: refer?
2a) Explanation:
3) Engineer 3: Work-energy theorem tells us that the larger pulley will result in higher angular speed of the fly wheel. The work done on the fly wheel by the falling mass is τ*θ, where τ is the torque and θ is the total angle the fly wheel turned. Since the torque is larger, the total work, and thus the kinetic energy of the fly wheel is larger. To what method of approaching this problem does Engineer 3: refer?
3a) Explanation:
Physics
ISBN: 978-0077339685
2nd edition
Authors: Alan Giambattista, Betty Richardson, Robert Richardson