Question

A particle is moving in (x-y) plane, in a circular path
with centre at origin. If at an instant the position of
particle is (i + j) . then velocity of particle may be​

Answer 1

Answer:

$\hat i-\hat j$

Explanation:

The position of the particle = $\hat i+\hat j$

Since the particle is moving in the x-y plane in a circular path

Therefore,

At any instant, the velocity vector will be perpendicular to the position vector

If the velocity vector is $\vec v$ then the dot product of velocity vector and the position vector will be zero

i.e. $\vec v.(\hat i+\hat j)=0$

Thus, one possibility of $\vec v$ is $\hat i-\hat j$

Note: If 4 options are given for the velocity vector then its dot product can be checked with the position vector whichever dot product is zero, will be the answer