Newton’s Second Law: Cart Accelerated by a Fan


Picture_N2_AirtrackA small fan accelerates and decelerates a cart on an air track.



Principles Illustrated

Newton’s Second Law with a fairly constant force from a small, battery powered fan.

NCEA & Science Curriculum

SCI 1.1, PHYS 2.4


Set cart in motion by turning on the fan and observe. Note that the cart must be balanced. If an extra mass is placed at one end of the cart then the cart will sit on the track at an angle. This can cause a quite noticeable net force on the cart, accelerating it with the heavy end forward as the angled cart forces air backward. In this picture a fan has been added to the right end of the cart and a balancing mass has been added to the back end of the cart.


Individual teachers are responsible for safety in their own classes. Even familiar demonstrations should be practised and safety-checked by individual teachers before they are used in a classroom.

Related Resources

Newton’s First Law on an Air Track

Teaching Resources

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This teaching resource was developed with support from

The MacDiarmid Institute
Faculty of Science, Victoria University of Wellington
School of Chemical and Physical Sciences, Victoria University of Wellington


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