If I apply $5\mathrm{N}$ force on a object for $2$ seconds, can I say that I applied $10\mathrm{N}$ force?
2 Answers
No, because the force was 5 N the entire time.
You can say that the object (provided there are no other forces acting on it) received an impulse of $\Delta p = 10 \rm\,N\cdot s$ due to the force you provided.
The relationship you are looking for is between momentum, force, and time:
$$ F = \frac{\Delta p}{\Delta t}. $$
No, not at all. When a constant force $F$ of $5\mathrm{N}$ is applied for a time duration $t$ of $2\mathrm{s}$, it imparts an impulse $F\cdot t=5\cdot 2=10\mathrm{Ns}$ to an object which causes the change in linear momentum $\Delta p=\Delta (mv)=10\mathrm{kgm/s}$ of that object.