Propulsive efficiency

Propulsive efficiency is like how well a car moves forward when it goes vroom.

When you go vroom, the car's engine makes power, and the power goes through the wheels to move the car forward. But not all the power makes the car go forward. Some of the power gets lost in making things like heat or noise.

Propulsive efficiency is like how much of the power goes into moving the car forward. If the car's engine makes 100 vrooms of power, and 70 vrooms go into moving the car forward, then the propulsive efficiency is 70 percent.

It's like when you blow up a balloon and let it go. The air inside the balloon is like the car's engine making power. The force that lets the balloon fly around is like the car moving forward.

If you blow up the balloon and let it go, but the air leaks out of the balloon too quickly, the balloon won't fly very far. This is like low propulsive efficiency. But if the air stays inside the balloon and pushes it forward strongly, the balloon will fly a lot farther. This is like high propulsive efficiency.