Chapter 6 - Linear Momentum and Collisions - Learning Path Questions and Exercises - Conceptual Questions - Page 214: 19

The larger lower stages carry more fuel to produce greater impulses on the successively smaller upper stages. Once the fuel in each successive lower stage is gone, that stage can be jettisoned and does not need to be accelerated after that.

The larger lower stages carry more fuel to produce greater impulses on the successively smaller upper stages. Once the fuel in each successive lower stage is gone, that stage can be jettisoned and does not need to be accelerated after that.