question_answer

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

A) \[\text{3}.\text{14m}{{\text{s}}^{-1}}\]                                

B)  \[2.0\text{m}{{\text{s}}^{-1}}\]

C) \[1.0\text{m}{{\text{s}}^{-1}}\]                                

D)  zero

Correct Answer: B

Solution :

                 Average velocity \[=\frac{displacement}{time\text{ }taken}\]                 or            \[{{\vec{v}}_{av}}=\frac{\Delta \,\vec{r}}{\Delta \,t}\] As, displacement is AB = 2m                 \[{{\vec{v}}_{av}}=\frac{2\,m}{1\,s}=2\,s{{m}^{-1}}\]