A body is moving with uniform speed v on a horizontal circle from A as shown in the figure. Change in velocity in the first quarter revolution is

Options

A. v North
B. `sqrt(2)v` South- West
C. `sqrt(2)` North-West
D. 2v West

Answer

B

Explanation

For quarter revolution `Deltavecv=vecv_(2)-vecv_(1)` and angle between `vecv_(1) and vecv_(2)` is `90^(@)`

`Deltav= sqrt((v_(1)^(2)+v(2)^(2)-2v v_(1)cos theta)`
`Deltav=(sqrt(v_(2)^(2)+v_(1)^(2))= sqrt(v^(2)+v^(2))= sqrt(2v): " " alpha "tan"^(-1)(v)/(v), " " =45^(@) :. " " Delta vecv= sqrt(2)v` (South West)