# How Newton's 3rd Law Gets Us off the Ground

## Explore Newton’s Third Law with Future NASA Aeronautics concepts

Forces come in pairs. Newton’s 3rd Law says for every action, there is an equal and opposite reaction. An aircraft is a perfect real-world example of force pairs.

Even sitting on the ground, the plane exerts a force down on the ground and the ground exerts an equal force back up on the plane.

### Weight

Weight is the force generated by the mass of the Earth pulling on an object. As the Earth exerts a force on NASA’s Super Guppy, the airplane exerts an equal and opposite force on the Earth.

### Drag

Drag is an aerodynamic force generated by the resistance of a body moving through a fluid (liquid or gas).

### Thrust

Jets push exhaust out the back of the engine, and thrust is produced in the opposite direction. Thrust must be greater than or equal to drag in order for the plane to move forward.

### Thrust

This quadcopter’s rotary blades produce enough reaction to thrust the unmanned aerial vehicle (UAV) off the ground. This vertical takeoff is referred to as EVTOL.

### Lift

Lift from an airfoil: the air is pushed down by the airfoil’s action, and the wing is pushed up. Lift must meet or exceed the weight of the object to fly.