  Difficulties presented by students on the concept of instantaneous velocity
are well known. This is in part due to instantaneous speed being often defined
in terms of the notion of mathematical limit, which may not be clear to many
students in introductory physics courses. In this work we present a
complementary teaching proposal that can help students to get a better grasp of
instantaneous velocity. The approach is based on Galileo's ideas on
instantaneous speed, which he borrowed from the Mertonian scholars much before
infinitesimal calculus was developed.
