There are two factors that affect the effect of changes, they are
(i) Magnitude usually expresses the strength of force.
(ii) When the force is applied on the body, then at that moment the force acts, has direction as well.
So, if the magnitude or direction of force or both, Change, then its effect also changes.

The force on unit area is called pressure, works on the chapatis. This is the pressure which works on the dough balls and make them chapatis with the help of machine.

Since, there are many actions which give us the feeling of force like we hit or catch many objects in our regular routine. Most of the times, we see that the moving ball stops after sometime and it changes the direction of motion when it is hit by a bat also, when we compress a spring, its shape and size changes.

Two forces are as follows:
(i) Gravitational force
(ii) Friction due to air or force of friction

The two examples are as follows:
(i) Spring When we compress or stretch the spring, it changes its shape.
(ii) Foam When we compress the foam or sponge, it changes its shape.

The two examples are as follows:
(i) We push the door to open it.
(ii) We pull a drawer to open it.

It is the force of gravity which is responsible for the grains to fall down. 

The interaction of poles of two magnets are
(i) Unlike poles attract each other
(ii) Like poles repel each other.

The electrostatic force starts working between the cloth made of synthetic fibre and sticks to skin.

Yes, when we place our palm in front of a moving ball, then the palm apply a force on the moving ball and stop it.

Her friend should push the box towards East direction, so that it will start moving more fast towards East because the magnitude of force increases.

While walking on a sandy surface, one needs the footwears of larger area so that the pressure exerted on the ground is minimum. So, in this case, the woman having the sandals with pointed heels will be less comfortable in walking while the other woman wears sandals with flat sales feels more comfortable while walking on sandy beach.

Because needle tip has very less area of cross-section in comparison to that of our finger and we know that pressure exerted by a force is inversely proportional to the area where it has been applied, so pressure exerted will be more by the needle tip than the finger.