1G10.40 - Bicycle-Size Atwood's Machine
The Atwood's Machine is a two body system that demonstrates the interdependence of forces on two masses connected by a string on a pulley.
The bicycle Atwood is set into a static condition where the equal masses are not in motion and are at equal heights above the floor.
A small slotted mass is added to the balanced masses and the class observes an acceleration of the mass. If the equal masses are simply perturbed by a gentle push, the motion of both masses continues in a non accelerated condition.
Two masses connected by a "massless, inextensible" string on a pulley can reveal the subtle interplay of mass, acceleration and force. While experience prepares us to answer which way the pulley will spin if one mass is heavier than the other, characterizing the relationship between the acceleration of each mass, the force on each mass, and the tension of the string at different points is often challenging for students.