a particle is moving on a circular path with constant speed V it moves between two points A and - Physics - Motion in a plane

Question

a particle is moving on a circular path with constant speed V it
moves between two points A and B, which subtends an angle 60degree
at the centre of circle the magnitude of change in its velocity and
change in magnitude og its velocity during motion from A to B are
respectively
1) zero,zero
2) v,0
3) 0,v
4) 2v,v

Rajnish Singh · Accepted Answer

Here it clear from the figure that change in magnitude of velocity
is zero since particle moves with constant speed and speed at A
equals to speed at B hence we can write
vb -va  = v -v =0
now magnitude of change =
here vb→ = vsinθi^ +vcosθj^and va→ = vsinθi^ -vcosθj^now vb→- va→  = vsinθi^ +vcosθj^ - vsinθi^ +vcosθj^                         =2vcosθj^                            = 2vcos600j^  = 2v×12j^ = v j^vb→- va→  =  v j^ = v
hence option 2 is correct
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