Let A be moving with a uniform speed v on a straight linear path.
let B be moving on a circular path of radius R, angular velocity w and time period T with a uniform speed u. u = R w. T = 2π/w
1) total length of distance travelled by A and B will be same in equal intervals.
magnitude of displacement after time t, of A is v t.
magnitude of displacement after time t of B is between 0 and 2 R only. maximum displacement is when the object is at the other end of the circle.
2) velocity vector of A is constant in magnitude and direction.
that of B is changing in direction at every instant. so is its linear momentum.
3) acceleration of A = 0
acceleration of B = m u² / R always pointed to towards the center of circle.
this is called centripetal acceleration.
4) there is no net resultant force acting on A. There is a net resultant force on B.
5) there is an angular momentum , angular velocity for B.
those are 0 for A.