NEET-XII-Physics

08: Work and Energy

with Solutions - page 3
Qstn# iii-3 Prvs-QstnNext-Qstn
  • #3
    A particle is acted upon by a force of constant magnitude which is always perpendicular to the velocity of the plane. The motion of the particle takes place in a plane. It follows that
    (a) its velocity is constant
    (b) its acceleration is constant
    (c) its kinetic energy is constant
    (d) it moves in a circular path.
    digAnsr:   c,d
    Ans : (c) its kinetic energy is constant
    (d) it moves in a circular path.
    When the force on a particle is always perpendicular to its velocity, the work done by the force on the particle is zero, as the angle between the force and velocity is 90`` °``. So, kinetic energy of the particle will remain constant. The force acting perpendicular to the velocity of the particle provides centripetal acceleration that causes the particle to move in a circular path.
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