# plz read this carefully and answer : If block A is moving on block B ,and both the blocks are moving and in the same direction and speed ,then there is no relative motion between block A and block B . But block B is moving on ground so there exists a relative motion between block B and the ground , no matter block B is moving or not .plz tell me i am right or wrong about this concept .Also tell what will happen if the blocks are moving with unequal speed or in the opposite direction .

Dear Student
Block A is on block A and they are moving in same direction with same velocity. Than the relative velocity is ${v}_{a}-{v}_{b}=0$
The ground velocity is zero. So relatiove velocity with respect to ground will be ${v}_{gb}=v-0=v$
If they are moving in different directions than ${v}_{ab}={v}_{a}-\left(-{v}_{b}\right)=2v\phantom{\rule{0ex}{0ex}}$ if they are

if they have same velocity in opposite directions.
Regards

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No idea
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