Lowering a bucket - the rope, the bucket, the air, the earth#
Ahmed stands on a cliff, and gently lowers a bucket of water to the ground using a rope. The bucket starts out with an initial downwards velocity, but Ahmed is tightening their grip on the rope as it slides through their hands, so that is slows as it descends, and when the bucket touches the ground it has zero velocity.
Consider the energy in the situation and how the work is being done if the system consists of the rope, the bucket, the air, and the earth.
Is the system open or closed?
None of the above
What types of energy are in the system? Are they increasing or decreasing?
Select all the choices that apply.
Note: You will be awarded full marks only if you select all the correct choices, and none of the incorrect choices. Choosing incorrect choices as well as not choosing correct choices will result in deductions.
Kinetic energy - Decreasing
Kinetic energy - Increasing
Gravitational potential energy - Decreasing
Gravitational potential energy - Increasing
Thermal energy - Decreasing
Thermal energy - Increasing
Elastic potential energy - Decreasing
Elastic potential energy - Increasing
Motion energy - Decreasing
Motion energy - Increasing
Is the work from external forces being done on the system positive or negative?
Both positive and negative (by different external forces)
No external forces
Problem is licensed under the CC-BY-NC-SA 4.0 license.