Answer:

case 1:- initial velocity of moving body, u = -11cm/s.

initial position of body ,  = 3cm

final position of body , s = -5cm

taken taken by body to move initial position to final position, t = 2s

using formula,

s =  + ut + 1/2 at²

or, -5cm = 3cm + (-11cm/s) × 2s + 1/2 × a(2s)²

or, -5 - 3 = -22 + 1/2 × a × 4

or, -8 + 22 = 2a

or, a = 7cm/s²

hence, acceleration of body will be 7cm/s²

if velocity is given -11cm/s , then magnitude of acceleration will be 7cm/s².

case2 : if initial velocity of body, u = 11 cm/s

initial position of body ,  = 3cm

final position of body , s = -5cm

taken taken by body to move initial position to final position, t = 2s

using formula,

s =  + ut + 1/2 at²

or, -5cm = 3cm + (11cm/s) × 2s + 1/2 × a(2s)²

or, -5 - 3 = 22 + 1/2 × a × 4

or, -8 - 22 = 2a

or, a = 15cm/s²

hence, if initial velocity of body is 11cm/s then, magnitude of acceleration will be 15 cm/s² .