NEET-XII-Physics

10: Rotational Mechanics

with Solutions - page 2
Qstn# ii-2 Prvs-QstnNext-Qstn
  • #2
    A body is uniformly rotating about an axis fixed in an inertial frame of reference. Let
    →Abe a unit vector along the axis of rotation and
    →Bbe the unit vector along the resultant force on a particle P of the body away from the axis. The value of
    →A . →Bis
    (a) 1
    (b) -1
    (c) 0
    (d) none of these.
    digAnsr:   c
    Ans : (c) 0
    The unit vector along the axis of rotation and the unit vector along the resultant force on the particle are perpendicular to each other in a uniform rotation.
    Therefore, we have:
    `` \stackrel{\to }{A}.\stackrel{\to }{B}=0``
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