Support force (Normal Force)

When stand on the ground heaviness is pulling you down, but you no falling. In fact you room in revolution equilibrium for this reason the ground have to be providing a supporting pressure that balances her weight. The ground offers that pressure in an answer to compression brought about by her weight. As soon as solid objects push back versus forces that are deforming lock we speak to that responsive push-back the regular Force.

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Reinforcement Activity

Push her finger down into your palm and also feel the resistance from her palm.

That resistance is the regular force.

When you pull her finger away from her palm, the normal force from your palm go away.


Everyday Example<1>

In the diagram below, we check out a human being placing a bag of dog food on a table. Once the bag the dog food is put on the table, and also the human being lets go, just how does the table exert the force important to balance the load of the bag? While girlfriend wouldn’t view it v your nude eye, the table sags slightly under the fill (weight of the bag). This would be remarkable if the fill were put on a slim plywood table, yet even a sturdy oak table deforms as soon as a force is applied to it. That resistance to deformation causes a restoring force much choose a deformed feather (or a trampoline or diving board). When the load is put on the table, the table sags till the restoring force becomes as big as the load of the load, putting the load in equilibrium. The table sags quickly and the sag is slight, so we perform not notification it, yet it is comparable to the sagging the a trampoline or a hammock when you rise on.

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The person holding the bag of dog food have to supply an upward pressure equal in size and also opposite in direction come the pressure of heaviness on the food. The card table sags when the dog food is inserted on it, much like a stiff trampoline. Elastic restoring pressures in the table prosper as the sags until they it is provided a normal pressure equal in size to the come the weight of the load. Photo credit: university Physics
Normal Force and also Weight

If friend place things on a table the normal force from the table support the weight of the object. For this reason normal force is sometimes referred to as support force. However, regular is another word for perpendicular, so we will stick v normal force because it reminds us of the crucial fact that the regular force constantly acts at an angle of 90° to the surface. That does not mean the normal force always suggest vertically, nor is it always equal come an object’s weight. If you press horizontally top top the wall, the wall surface pushes ago (keeping her hand from moving through the wall). The pressure from the wall is a common force, but it acts horizontally and is not equal to your weight.

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Situations where normal force is no equal to the weight of the object. Adjusted fromGarscon Plancher”byObiwancho,and“Trek ~ above the Viedma Glacier”byLiam Quinn “U.S. Air force Chief grasp Sgt. Suzan Sangster”released by the joined States armed Forces v the ID090815-F-3140L-048

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In each case pictured over the normal force is not equal to body weight. In the left photo the normal force is less than body weight, and also acting horizontally. In the middle picture the normal force is less than body weight and also acting in ~ an angle. In the right image the normal pressure on the drill is an ext than it’s own weight because Master Sgt. Sangster is also pushing down on the drill. The normal pressure on master Sgt. Sangster’s feet is much less than she weight because she is additionally receiving an increase normal force from the drill handle.

Often (N) is supplied as a prize for typical force, but we space using N to abbreviate because that the SI pressure unit Newtons, so rather we will usage

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. The normal pressure comes increase so often students frequently accidentally begin to refer to normal pressure as “natural force” instead, therefore watch out for that possible source the confusion.


attraction in between two objects due to their massive as explained by Newton"s Universal legislation of Gravitation


any communication that causes objects v mass to change speed and/or direction that motion, other than when well balanced by other forces. We experience pressures as pushes and also pulls.


reduction in size led to by application of compressive pressures (opposing forces applied inward come the object).

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the outward force supplied by an object in response to gift compressed native opposite directions, generally in referral to hard objects.


the pressure of gravity on on object, commonly in referral to the pressure of gravity caused by planet or another celestial body


a pressure that often tends to move a system back toward the equilibrium position


a state of having actually no unbalanced forces or torques


at an angle of 90° to a offered line, plane, or surface


a device of physical units ( SI systems ) based upon the meter, kilogram, second, ampere, kelvin, candela, and also mole