Question

The ratio of the numerical value of the average velocity and average speed of body is always

• A. unity
• B. unity or less
• C. unity or more
• D. less than unity

Answer 1

Answer: (B)

The average speed of a particle in a given interval of time is defined as the ratio of distance travelled to the time taken while average velocity is defined as the ratio of displacement to time taken. Thus, if the distance travelled is As and displacement of a particle is $\Delta r$ in a given time interval $\Delta t$ then $v_{av}=$ average speed $=\frac{\Delta s}{\Delta t}$ and $v_{av}=$ average velocity $=\frac{\Delta r}{\Delta t}$ So, the required ratio is always unity or less than one.