Question

A body suffers retardation of $1m{s}^{-2}$ means

• A. its velocity increases by $1m{s}^{-1}$ per second
• B. its velocity remains constant
• C. its velocity decreases by $1m{s}^{-1}$ per second
• D. none of these

Answer 1

The correct option is C its velocity decreases by $1m{s}^{-1}$ per second

Acceleration is the rate of change of the velocity of an object with respect to time. Positive acceleration means increase in velocity with time and negative acceleration means decrease in velocity per unit time . Negative acceleration is also called retardation.

So retardation means rate of decrease of velocity per second.
So, retardation of $1m{s}^{-2}$ = decrease of $1m{s}^{-1}$ velocity per second.