A car is moving round a circular track with a constant speed `v "of" 20 m s^(-1)` (As shown in figure).At different times,the car is at A,B and C,respectively . Find the velocity change (a) from A to C, and (b) from A to B.
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Explanation

a. Change in velocity,as the particle moves from A to C,id the diffrence of final velocity vector and initial velocity vector.
`Deltavec(v)_(AC) = vec(v_C)-vec(v_(A)) =vec(v_c)+(-vecv_(a))`
(if we take left direction as positive , the right direction will be negative.)

`Deltav_(AC)=20+20=40 ms^(-1)`
As `Deltav_(AC)` is positive, hence, change in the velocity should be in the direction of left,i.e.,in the direction of `vecv_c`
`Deltavecv_(AC)=40ms^(-1)` in the direction of `vecv_c`
b. Change in velocity,as the particle moves from A to B,
`Deltavecv_(AB)=vecv-vecv_A=vec(v_(B))+(-vec(v_A))`
`Deltav_(AB)=sqrt(20^2+20^2)=sqrt(800)ms^(-1)`
`tantheta=20/20=1,theta=45^(@)`
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