Question

A particle goes from point $A$ to point $B$, if moving in a semicircle of radius $1.0m$, in $1.0s$, as shown in the figure. The magnitude of the average velocity of the particle is

• A. $3.14m{s}^{-1}$
• B. $2.0m{s}^{-1}$
• C. $1.0m{s}^{-1}$
• D. zero

Answer 1

Answer: (B)

Average velocity $=\frac{\text{ displacement }}{\text{ time taken }}$

or ${\vec{v}}_{av}=\frac{\Delta \vec{r}}{\Delta t}$
As, displacement is $AB=2m$
${\vec{v}}_{av}=\frac{2m}{1s}=2s{m}^{-1}$