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1. Homework Statement
Assume no friction for 1  6
1. Draw a free body diagram of the fly wheel (from above), and a free body diagram of the weight (from side).
2. What force appears in both diagrams?
3. What is the relationship between the torque on the flywheel and the tension in the string?
4. What is the relationship between the angular acceleration of the flywheel and the linear acceleration of the weight?
5. What is the formula for the moment of inertia of a solid disk?
6. Based on 1  5, write an equation that predicts angular acceleration of the flywheel, given mass and radius and g.
7. Suppose there is friction between fly wheel and stand that holds the fly wheel, so eventually it stops. As the weight drops, will the angular acceleration of the fly wheel be larger than, smaller than, that predicted by the equation in 6?
2. Homework Equations
angular acceleration = change in angular velocity / change in time
angular momentum = moment of inertia X angular velocity
lever arm = r X sin(theta) (perpendicular distance between axis of rotation and line of action of force) See image
moment of inertia = m X r^2
torque = r X F X sin(theta)
3. The Attempt at a Solution
1. See image
2. Tension
3. Torque = radius X Tension (because tension is the force)
4. distance from rest (d) = 1/2 a t^2 > a = 2 x d / t^2
Not sure how to relate this to angular acceleration?
5. I = M x R^2 / 2
6. Can't answer without #4..
7. Same as 6
Assume no friction for 1  6
1. Draw a free body diagram of the fly wheel (from above), and a free body diagram of the weight (from side).
2. What force appears in both diagrams?
3. What is the relationship between the torque on the flywheel and the tension in the string?
4. What is the relationship between the angular acceleration of the flywheel and the linear acceleration of the weight?
5. What is the formula for the moment of inertia of a solid disk?
6. Based on 1  5, write an equation that predicts angular acceleration of the flywheel, given mass and radius and g.
7. Suppose there is friction between fly wheel and stand that holds the fly wheel, so eventually it stops. As the weight drops, will the angular acceleration of the fly wheel be larger than, smaller than, that predicted by the equation in 6?
2. Homework Equations
angular acceleration = change in angular velocity / change in time
angular momentum = moment of inertia X angular velocity
lever arm = r X sin(theta) (perpendicular distance between axis of rotation and line of action of force) See image
moment of inertia = m X r^2
torque = r X F X sin(theta)
3. The Attempt at a Solution
1. See image
2. Tension
3. Torque = radius X Tension (because tension is the force)
4. distance from rest (d) = 1/2 a t^2 > a = 2 x d / t^2
Not sure how to relate this to angular acceleration?
5. I = M x R^2 / 2
6. Can't answer without #4..
7. Same as 6
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