# What is a Real World Application of an Atwood Machine?

July 16, 2023
David Sunnyside

#### What is a Real World Application of an Atwood Machine?

An atwood machine, also known as Atwood's machine, is a classic demonstration to help students understand dynamic forces and Newton’s Second Law. It consists of two blocks connected by a light string and suspended from a low friction pulley. When the system is activated, the heavier mass falls and the lighter one rises. The force of the weights on the masses and the tension in the string are equal and opposite, which results in a net downward force (m1g) and an upward force (m2g). The gravitational acceleration of Earth (9.8 m/s2) is the same for both masses and is added to the net downward force to give a constant total acceleration, (a).

To begin, construct an Atwood Machine with a low friction pulley and some string. Suspend the heavier mass m1 above the lighter mass, m2 on a ring stand or other support. The masses should be evenly spaced and the string should run over both masses without contacting them. Note that the system does not actually accelerate at a constant rate, since energy gets lost in friction and frictional forces in the pulley and string.

Using a spreadsheet program or graphing software, plot the Constant Total Mass data. Draw a best-fit line to the data and label the slope of the line. Record this data in the Data Table and in the Lab Report section.

David Sunnyside
Co-founder of Urban Splatter • Digital Marketer • Engineer • Meditator