A particle is acted upon by a force of constant magnitude which is always perpendicular to the velocity of the particle. 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.

As no force is acting in direction of velocity.. there would b no change in velocity.. a) is correct

F=mrw^2F=mv^2/rNow F IS CONSTANTThus,mv^2/r is constantNow r will be constant Thus mv^2 is constantThis implies Kinetic energy I.e. mv^2/2 is also constantHere velocity and acceleration will not be constant since velocity is a vector quantity and in a circular motion velocity will keep changing

A particle is acted upon by a force of constant magnitude which is always perpendicular to the velocity of the particle. The motion of the particle takes place in a plane. It follows that :c) its kinetic energy is constant