Is ‘velocity’the displacement of an object during specific unit of time?

Yes

Explanation:

The displacement covered by a body in unit time is called velocity.

force is mass*acceleration.

we have a very small mass: 11.4*0.001 kg

if we want 0.035n of force, we need an acceleration:

0.035 = 11.4*0.001*a

a = 0.035/(11.4*0.001) m/s^2