Question

What is the phase difference between
(i) velocity and acceleration
(ii) acceleration and displacement of a particle executing SHM?

Answer 1

[Velocity is the distance teavelled by a moving object in a particular direction.
Acceleration is the rate of change of velocity with time.}
Acceleration is the rate of change of velocity with time.
Displacement is the other name of distance

Answer 2

velocity :- the rate of change of displacement .

v =D/T
ITS S.I UNIT IS m/sec

and

Acceleration is the rate of change of velocity. it is a vector quantity . its formula 

a  =  v-u/t

ITS S.I UNIT IS m/s²

it is the ans of first one