How much work is done by the centripetal force on an object moving in uniform circular motion?

$A$ particle moves along a circular path of radius $r$ with uniform speed $v$. The angle described by a particle in one second is

$A$ cycle wheel of radius $0.4\ m$ completes one revolution in one second. Then,the acceleration of a point on the rim of the cycle wheel will be:

$A$ particle completes $2$ revolutions in a circular path of radius $3$ cm. The angular displacement of the particle will be (in radian) (in $\pi$)

$A$ particle moves in a circle of radius $25\, cm$ at two revolutions per second. The acceleration of the particle in $m/s^2$ is

An object moves at a constant speed along a circular path in a horizontal plane with its centre at the origin. When the object is at $x = +2\,m$,its velocity is $-4 \hat{j}\,m/s$. The object's velocity $(v)$ and acceleration $(a)$ at $x = -2\,m$ will be