A stone tied to the end of a string of 1 m long is whirled in a horizontal circle with a constant speed. If the stone makes 22 revolutions in 44 s, what is the magnitude and direction of acceleration of the stone?

As the speed is constant throughout the motion, so it is case of uniform circular motion. Therefore, its radial accelerationa = rω2 = r(2πnt)2 = r×4π2n2t2= 1×4×π2×(22)2(44)2 = π2m/s2This acceleration is directed along radius of circle towards center of circle.