Periodic vs. oscillatory motion

[abdsaber000]

Homework Statement

To and fro motion of a particle about a mean position is called:
(oscillatory motion and periodic - oscillatory motion and S.H.M - harmonic motion and periodic)

Relevant Equations

none

I'm hesitated between the first and second choice

 

[berkeman]

Welcome to PF.

Does your textbook give definitions of each? If not, have you looked online (like at Wikipedia) to see what the common definitions are?

 

[abdsaber000]

Welcome to PF.

Does your textbook give definitions of each? If not, have you looked online (like at Wikipedia) to see what the common definitions are?

yeah my textbook gives it a definition, the defintion mentioned in the question the definition of the oscillatory motion , but i know that oscillatory motion is a special case of periodic motion . in addition that in S.H.M the acceleration is directly proportional to the displacement. but the S.H.M has also a mean position like the oscillatory. that's why i can't decide which is answer is correct.

 

[haruspex]

(oscillatory motion and periodic - oscillatory motion and S.H.M - harmonic motion and periodic)

It is unclear where one choice ends and the next begins.
Please put each choice on a separate line.
If the above mixes in definitions of the terms, please make that clearer too.

S.H.M has also a mean position

I would think any regular oscillation has to have a mean position.