# Relationship between normal force and gravity

### Normal Force and Force of Gravity: When and why are they equal? | Physics Forums In mechanics, the normal force F n {\displaystyle F_{n}\ } F_n\ is the component of a contact where N is the normal force, m is the mass of the object, g is the gravitational field strength, and θ is the As explained before, the normal force is a contact force, that is, the resultant of the forces between the constituents of the. In non-mathematical terms, the normal force is what keeps us from sinking into the ground: we experience the force of gravity and yet we aren't sucked into the. A force is an interaction between objects that tends to produce acceleration of the objects. Objects with mass exert forces on each other via the force of gravity.

## Types of Forces

The magic disappears when you look at things from a quantum perspective. When you are standing still on the floor, the atoms at the very bottoms of your shoes are not quite touching the atoms at the very top of the floor.

The electrons in those atoms repel each other. You are, in a sense, floating just above the floor. Suppose you pick up a heavy book.

The force due to gravity is pulling down on you a bit more.

### What is normal force? (article) | Khan Academy

Your shoes descend a tiny, tiny bit to narrow the tiny very tiny! This increases the electrical repulsion, compensating for the added weight of the book. How does the table know to exert just the right amount of force to prevent the object from passing through it? When solid objects deform they typically try to restore themselves and "spring back" to their natural shape. The heavier the weight, the greater the deformation, the greater the restoring force trying to bring the surface back to its natural shape. This deformation would be noticeable if the load were placed on a card table, but even rigid objects deform when a force is applied to them.

## Normal force

Unless the object is deformed beyond its limit, it will exert a restoring force much like a deformed spring or trampoline or diving board. So when the load is placed on the table, the table sags until the restoring force becomes as large as the weight of the load.

• Homework Help: Normal Force and Force of Gravity: When and why are they equal?
• What is normal force?

At this point the net external force on the load is zero. Mass is a good measure of inertia; light objects are easy to move, but heavy objects are much harder to move, and it is much harder to change their motion once they start moving. Do Newton's laws apply all the time? As long as we're in a stationary reference frame, or even moving at constant velocity, Newton's law are valid. Such reference frames are called inertial reference frames. Newton's Laws are not enough to account for motion observed from non-inertial accelerating reference frames.

Newton's Second Law What is the acceleration produced by applying a force to an object?

### Gravity and the Normal Force

Newton's second law states that the acceleration of an object is proportional to the net force and inversely proportional to the mass of the object. These statements are summarized by: Although the forces between two objects are equal-and-opposite, the effect of the forces may or may not be similar - it depends on the relative masses of the objects.

If we drop a g 0. The ball exerts an equal-and-opposite force on the Earth, so why doesn't the Earth accelerate upwards towards the ball? It does, but the mass of the Earth is so large 6. When objects have similar mass, the equal-and-opposite pairs of forces are much easier to see.

Force of Gravity Whenever two objects are touching, they usually exert forces on each other. The force of gravity, on the other hand, is an example of a force that exists between objects without them having to be in contact. Objects with mass exert forces on each other via the force of gravity.