In 1991, the Ministry of Posts and Telecommunications issued a postcard: JP, 29, commemorating the postage postcard, the 400th anniversary of Galileo's discovery of "equivalence of inertial mass and gravitational mass" (1591-1991).
I remember when I was in elementary school, there was a new batch of books in the school library, including Galileo's biography, and my classmates rushed to see this new book, and I was deeply attracted by Galileo's love of exploring science since he was a child, such as the pendulum phenomenon and free-fall experiments.
I remember very clearly that my classmates and I climbed to the tallest building (unfortunately only three floors), experimented with table tennis balls, glass marbles, cardboard boxes, etc., arguing about the heavy items and the light items landing first.
Friends, do you have an experiment! Do you know which one lands first?
