University of California, San Diego
Physics 11A - Survey of Physics

H. E. Smith   Fall 2002

   Physics 11a - Lecture #6 Using Newton's Laws
   15 October 2002

Question for next lecture: A farmer hitches up his horse to his wagon to carry a load of halloween pumpkins into town. The horse protests: "I will not be able to pull the Wagon into town."

"Why not?!" enquires the farmer.

"Physics!" replies the horse, "specifically Newton's Third Law which requires that no matter how hard I pull on the wagon, the wagon will pull back on me with equal force. The harder I pull forward, the harder the wagon will pull backward, so that no forward motion can result."

What is the problem here?

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Gene Smith

Last modified: Th., 17 Oct. 2002