Rotational Motion

bfr

1. Homework Statement

I did a lab today where a weight was tied to a string. The string was wrapped around part of the circumference of a wheel, and then the end was taped down. So, when I let go of the wheel and the weight, the force of gravity on the weight causes the wheel to turn. I have two questions:

1. Is the angular momentum of the system made up of the wheel and the mass conserved?
2, Is the tension in the string constant?

2. Homework Equations

|Torque|=|F||r|sin(θ)
Angular momentum=I*$$\omega$$

3. The Attempt at a Solution

1. I think it isn't conserved because the force of gravity acting on the mass accelerates the system, making angular momentum not be conserved.
2. The tension is constant because it equals the mass of the weight times 9.8.

Related Introductory Physics Homework Help News on Phys.org

Dr.D

You say "the end was taped down." Do you mean the end of the string was taped down? If so, how did this permit the system to move?

With regard to the tension in the string, draw some FBDs and write some equations of motion before you jump to a conclusion here.

Physics Forums Values

We Value Quality
• Topics based on mainstream science
• Proper English grammar and spelling
We Value Civility
• Positive and compassionate attitudes
• Patience while debating
We Value Productivity
• Disciplined to remain on-topic
• Recognition of own weaknesses
• Solo and co-op problem solving