Atwood Machine
Solve an ideal Atwood machine for acceleration and string tension from two hanging masses, or find the unknown mass. Includes a = g|m₂−m₁|/(m₁+m₂) and T = 2m₁m₂g/(m₁+m₂) with step-by-step working.
Key formula
a = g|m2-m1|/(m1+m2), T = 2 m1 m2 g/(m1+m2)
About this tool
An Atwood machine connects two hanging masses with a string over a pulley. This page keeps a = g|m₂−m₁|/(m₁+m₂) and T = 2m₁m₂g/(m₁+m₂) visible so pulley homework stays consistent on free-body signs and the ideal-pulley assumptions.
How to use this calculator
- Choose the variable you want to solve for and confirm which values are already known.
- Enter inputs in consistent units before calculating so the formula is applied correctly.
- Check whether the result is physically reasonable by comparing it with the size of the inputs.
- Use the step-by-step breakdown to see how the equation was rearranged and evaluated.