Even in 1800, it was understood—by at least one person, a certain George Cayley—that two forces, weight and drag, were antagonistic to flight and that there must be two corresponding forces to ...

There are many ways to describe the forces around sails — in fact, around any foil. One of the most straightforward ways is to split the forces into lift and drag. The lift force is, by definition, ...

Introduction Not even the strongest human could lift a truck into the air. Our brains, however, are smart enough to create a tool that can lift heavy objects for us: hydraulic lifts! You can find them ...