A0.30 kg mass is attached to a long string and resolves clockwise ( looking down from the top) in a horizontal circle of radius 0.10 m with a speed of 0.50 m/s and a period of 1.3 s.

a) determine the ceptipetal acceleration of the mass.

There is no requirement of Time period if u r given the rest data.
Centripetal force(F) = mv²/r.
where m is mass of body , v is the speed , and r is the radius of the path.
=> F =( 0.30×0.50×0.50)/0.10 = 0.75 m/s².
Its direction is radially inwards.
Hope it helps!!!