Question

what is meant by retardation ? how to derive it?

Answer 1

$$\begin{gathered} \mathrm{Retardation}: \\ \mathrm{The}\mathrm{rate}\mathrm{of}\mathrm{change}\mathrm{of}\mathrm{velocity}\mathrm{in}\mathrm{the}\mathrm{case}\mathrm{of}\mathrm{decreasing}\mathrm{velocity}\mathrm{is}\mathrm{called} \\ \mathrm{as}\mathrm{retardation}.\mathrm{It}\mathrm{is}\mathrm{also}\mathrm{equal}\mathrm{to}\mathrm{negative}\mathrm{acceleration}. \\ \mathrm{Expression}: \\ \mathrm{Retardation}=\frac{\mathrm{Initial}\mathrm{velocity}-\mathrm{Final}\mathrm{velocity}}{\mathrm{time}} \end{gathered}$$