In the economic growth model of Robert Solow and Trevor Swan, the steady state occurs when gross investment in physical capital equals depreciation and the economy reaches economic equilibrium, which may occur during a period of growth.

When can you assume steady state?

The steady state approximation assumes that the concentration of reaction intermediates remains constant throughout the reaction. The concentration of reaction intermediates is assumed to be steady because the intermediates are being produced as fast as they are consumed.

What is the time at steady state?

The time to reach steady state is defined by the elimination half-life of the drug. After 1 half-life, you will have reached 50% of steady state. After 2 half-lives, you will have reached 75% of steady state, and after 3 half-lives you will have reached 87.5% of steady state.