Collision between two balls accompanied by deformation: A qualitative approach to Hertz’s theory

When real balls collide they suffer deformation. Though the theory of collision accompanied by elastic deformation has been developed by H. Hertz a long time ago, it is rarely accounted for in elementary courses because of its mathematical intricacies. It is shown that an order‐of‐magnitude approach is nevertheless possible, and that the essentials of Hertz’s results can be obtained without recourse to complicated calculations.