Atwood's Machine with a spring scale Part 1: Qualitative Testing Experiment

Aim

A test of your model of the relationship between acceleration of an object and the sum of the forces exerted on it by other objects.

Prior Knowledge

Results of the previous experiment.

Description of the Experiment

Basic Atwood's machine set-up with a spring scale in the string. In this experiment the spring scale is attached to the side with the object that has less mass. Predict what will happen to the reading on the spring scale when the objects are released. Choose your system for analysis and use motion and force diagrams to make the prediction.

Addtional Information

The scale on the spring scale is difficult to read. The zero point is at the top most point of the dial as seen by the viewer. The scale then reads increasing force in a clockwise direction from that zero point

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Questions

1. What objects exert forces on the object on the right before it is released? Draw a force (free-body) diagram for the object. Decide which of this forces corresponds to the reading of the scale.
2. What is the direction of the object's acceleration after it is released? Draw a motion diagram before you answer the question. How do you need the change the free-body diagram to be consistent with the motion diagram?
3. Draw a motion diagram and a free-body diagram for the object on the right after it is released. Decide which of this forces corresponds to the reading of the scale.
4. Based on your analysis, should the reading on the scale increase or decrease when the objects are released?