resistance and propulsion

Resistance is the force that opposes an object’s movement through a fluid or air, caused by friction and drag. Propulsion is the force that drives or pushes an object forward, such as an engine or a motor. To move efficiently, an object must generate enough propulsion to overcome resistance. Think of a boat: engine power (propulsion) pushes it through water, but water resistance pushes back. Likewise, a car’s engine generates force to counteract air resistance and rolling resistance of tires, allowing it to accelerate or maintain speed. Effective movement depends on balancing propulsion and resistance forces.