THROWING

Thanks to a falling apple, Isaac Newton formulated his laws of gravity in the 17th century. Objects as small as an apple or as large as a planet are subject to the same laws. And these laws also help us understand the trajectories and movements of sports, balls, ski jumpers, high jumpers, skaters, cyclists, and so on. The equations of motion can be written from Newton’s second law (see box Newton’s laws). Firstly, we need to determine the forces or actions exerted on the object, which then enables us to calculate the position and velocity of a body at any given moment as a function of its mass, initial position and velocity, and the initial effects it has been given.