Gravity can be acting on an object that's at rest. It happens all the time here, near the surface of the earth.jayjay55531 said:...if objects at rest have an acceleration of 0, and the net force on an objet equals m*a, then doesn't that mean there must be no net external force on the object? What am I missing here...??
SammyS said:there must be some other force or forces acting on the object to counteract the effect of the gravitational force.
It doesn't really matter whether the object is moving or not. If the object is stationary or moving at constant speed, then the sum of all forces must be zero. When object is on e.g. the surface of the Earth or on a table there is always normal force preventing the object from sinking through the surface as per Newton's III law.jayjay55531 said:...if objects at rest have an acceleration of 0, and the net force on an objet equals m*a, then doesn't that mean there must be no net external force on the object? What am I missing here...??
jayjay55531 said:...if objects at rest have an acceleration of 0
For a person standing on the ground, the ground itself is pushing upwards on the person, supporting the person.jayjay55531 said:What would these forces be, in the example of a person standing on the ground?
Gravity is a fundamental force of nature that attracts all objects with mass towards one another. This means that even stationary objects are subject to the force of gravity, which pulls them towards the center of the Earth.
The reason that stationary objects stay on the ground or remain in one place is due to the balance of forces acting upon them. Gravity is pulling the object downwards, but the object is also being supported by the ground, which exerts an equal and opposite force upwards.
Yes, gravity can act as a force on objects that are not on the ground. Any two objects with mass will experience a gravitational force between them, regardless of their location. The strength of this force depends on the masses of the objects and the distance between them.
The force of gravity between two objects decreases as the distance between them increases. This is described by the inverse square law, which states that the force of gravity is inversely proportional to the square of the distance between two objects. So, as an object moves closer to the Earth, the force of gravity acting on it increases.
No, the force of gravity cannot be cancelled out on a stationary object. This is because gravity is a fundamental force that exists between all objects with mass, and it is always acting on an object regardless of its position. However, the effects of gravity can be counteracted by other forces, such as the normal force from a surface or the force from an engine in a rocket.