Physics of Donkey Carts

Physics of Donkey Carts



Topic Cluster

Newtonian Physics


Naveed A. Malik
Pakistan Virtual University
Lahore, Pakistan

Lesson Feedback


This video lesson explores Newton’s Third Law of Motion through examination of several real world examples of this law in action, including that of a donkey cart – a site common in the streets of Pakistan. Students will understand that forces act on objects even if the objects appear to be static and that certain conditions – gravity in particular – affect how two objects interact. The time needed to complete this lesson is approximately 50-60 minutes, and students should be familiar with basic mechanics such as Newton’s laws, levers, etc. The materials required are a couple of spring balances, a meter rule, tape, pencil, two desks, and some lab weights (few grams each). The types of in-class activities for between the video breaks include active discussions and participation by students in activities related to the Third Law.

Instructor Biography

Dr. Malik is currently the Rector of the Virtual University of Pakistan. He obtained his Master’s degree in Physics from the University of the Punjab, Pakistan and later the Doctor of Science degree from M.I.T. in the field of Electrical Engineering and Computer Science. As a staff member at the University of the Punjab, Pakistan’s largest and oldest university, Dr. Malik established the Spark Source Mass Spectroscopy laboratory at the Centre for Solid State Physics and later became the founding chairman of the Department of Computer Science.

Additional Online Resources

PhET Interactive Simulations: Gravity Force Lab
This site, provided by the PhET Interactive Simulations from the University of Colorado at Boulder, allow students to visualize the gravitational force that two objects exert on each other and to change properties of the objects in order to see how it changes the gravity force.

ComPADRE Digital Library: Newton's 3rd Law
This site, sponsored by the ComPADRE Digital Library supporting faculty, students, and teachers in Physics and Astronomy Education, presents a WonderHowTo video that shows how Newton's Third Law of Motion can be demonstrated using a low-friction "sled" and two rubber bands. The video includes a brief description of Newton's third law and explains the reaction force on the sled. Links are provided for other related videos within the site.

ComPADRE Digital Library: Goddard Space Flight Center: Newton's Third Law of Motion
This site, sponsored by the ComPADRE Digital Library supporting faculty, students, and teachers in Physics and Astronomy Education, provides a lesson plan for teaching Newton's Third Law, including activities and exercises. Among the activities are balloon rockets and ball drops. The lesson plan also includes background information illustrating the law.

HippoCampus project: Newton’s Third Law
This site, sponsored by the HippoCampus project of the Monterey Institute for Technology and Education (MITE), provides a comprehensive video on the topic of Newton’s Third Law.