question_answer

A body in a uniform horizontal circular motion possesses a variable velocity. Does it mean that the K.E. of the body is also variable?                

Answer:

No ; K.E. of body = \[\frac{1}{2}m{{\upsilon }^{2}}=\frac{1}{2}m(\overset{\to }{\mathop{\upsilon }}\,,\overset{\to }{\mathop{\upsilon }}\,)\], which is scalar. In uniform circular motion, speed of body \[\upsilon \] remains constant, hence K.E. of body remains constant in uniform circular motion.