A particle travels from point A to B on a circular path of radius 15//picm . If the arc length AB be 10 cm , find the displacement (Figure)

A particle travels from point A to B on a circular path of radius 15//

1.	A particle travels from point A to B on a circular path of radius 15//picm . If the arc length AB be 10 cm , find the displacement (Figure)
Answer» Solution :Joining the initial (A) and final (B) positions of the body, the straight line AB is obtained which is its displacement (Figure) Weknow , `("Circumference") /("arc LENGTH")= (360^(@))/("Angle subtended by are at centre")` `:. (2pixx(15)/PI)/10=(360^(@))/(20)` `RARR 2 theta =120^(@)`.`rArr theta 60^(@)` Now from right angle `Delta ADO`, `AD=OA sin theta =(15/pi) sin 60^(@)=(15sqrt3)/(2pi)` `:. AB=2AD=(15sqrt3)/pi cm` along A to B Note, Distance is scalar, but displacement is a vector quantiy. Distance `ge` displacement If a particle stars from a point and reaches the same point at the end of its journey, then displacement is zero. However distance covered is not zero . The magnitude of displacement cannot EXCEED the distance of a particle in motion .