The normal force will not always equal m g mg mg . We might plug in a different acceleration, or there might be more forces to include, but the overall problem solving strategy of finding normal force using Newton’s second law would still be the same.

Hence, weight of a body will change from one place to another place because the value of g is different in different places. For example, the value of g on moon is 1/6 times of the value of g on earth. As mass is independent of g , so it will not change from place to place.

The results show that the influence of shape on perceived weight was at least partially independent of the influence of shape on perceived size, since shape had a statistically significant effect on perceived weight, even when the effects of perceived size on perceived weight were taken into account.

The normal reaction force is the force the ground exerts on the object to prevent the object from sinking into the ground. It can be zero. In which case, it would means that the object is floating just above the surface, not really touching it. But it cannot be negative.

No, the work done by normal forces is not always zero. In fact many common situations involve a normal force doing work. So in problems of blocks sliding down inclined planes, for example, the normal force of the plane on the block does no work because there is no motion in the direction of that normal force.

That does not mean the normal force always point vertically, nor is it always equal to an object’s weight. If you push horizontally on the wall, the wall pushes back (keeping your hand from moving through the wall). The force from the wall is a normal force, but it acts horizontally and is not equal to your weight.

The force of gravity, and the normal force, are not an action reaction pair. At first glance it may appear that these are action-reaction pairs because the forces are equal and opposite. However, they are not because both forces are acting on the same object.

The normal force balances the force of gravity. The gravitational force always acts in the downward direction and the normal force acts in the upward direction. The gravitational force is always perpendicular to the normal force. Hence, the tensional or a normal force called a support force.

The weight of any object is affected by three factors which are the object’s mass, the planet (the place) where the object exists, the distance between the object and the center of the planet.