Two blocks are connected by a light string which runs over a massless, frictionless pulley. One block rests on a level, frictionless surface and the other block hangs from the string. Both blocks are released from rest. Solve for the acceleration of the blocks as well as the tension in the connecting string.

MORE COMPLICATED VARIANTS OF THIS PROBLEM:
Surface Friction:    • The Basic Atwood Machine With Friction  
Tilted Surface:    • The Tilted Atwood Machine  
With Pulley Mass:    • The Atwood Machine With Pulley Mass  
Both Blocks Hanging With Pulley Mass:    • Acceleration of a Hanging Atwood Mach...  

This problem is a variant on the Atwood Machine (or Atwood's Machine)

The solution to this physics problem involves the application of Newton's 2nd Law and Free Body Diagrams to each object to generate a system of equations that can be used to derive the acceleration of system.

This problem typically appears in high physics courses as well as AP Physics. Mastering this problem is key to understanding the more complicated versions of this problem that are essential in understanding how to get a 5 on the AP Physics Exam.