Does Acceleration Require a Force to Be Involved?

[urooj]

Homework Statement

in accelaration is it must for a force to be involved?
is it must for accelaration to be constant in absence of force?

Homework Equations

f=ma

The Attempt at a Solution

well as far as my attempt goes for both q i am getting only one ans and that is yes.
but the actual answers are different,i.e,no.
i thought lot but i can't gety at it.
kindly help.

 

[Doc Al]

The first question is straightforward; the answer is yes.

But that second question is a strange one; in the absence of force what must the acceleration be?

 

[urooj]

i forgot to mention this that only real forces must be taken.
the actual q is matchin-
acceleration- i)frame dependent
ii)force must be involved
iii)must be in the direction of net for(including pseudoforce)
iv)must remain constant if no force is there

to which options does acceleration match?