Students associate pushes and pulls with moving or active objects they often believe that stationary or passive objects have no forces acting on them at all.
For example, students consider that an active object like a human hand can experience and produce forces, whereas a passive book lying at rest on a table is free from all forces. This view may be commonly held in the middle years and may be still be held by some students in the senior secondary years.
Students do have everyday experiences of objects breaking or bending when big forces are applied to them but they often fail to recognise that forces are present when there is no observable change or distortion as the force acts. For example, a chair collapsing under the weight force of a person or the stretching of a trampoline are seen to involve forces at work whereas an apple resting in a fruit bowl is not.
For both stationary and moving objects with unchanging speed and direction, all the forces acting on the objects are in balance with each other, i.e. they all cancel each other out.
Passive objects exert forces on objects that are exerting forces on them. For example, a heavy bag resting on a bed pushes on the bed because of its downward weight force and the bed pushes back up on the bag with a balancing force as it is squashed under the load.
All objects undergo some squashing (compression) or stretching and change shape when a force is applied to them. In the case of strong materials like concrete or steel table frames this compression is usually very small and not observable unless the applied force is very large.
When balanced forces are applied to a non-moving object, the object remains at rest. This is in accordance with Newton's first law of motion, which states that an object at rest will stay at rest unless acted upon by an unbalanced force.
The friction of a non-moving object is called static friction. It is the force that prevents the object from moving when a force is applied to it.
Drag forces are contact forces, as they act between a solid object and a fluid (such as air or water) that it moves through. The drag force arises due to the interaction between the object and the fluid surrounding it.
A non-contact force is any force applied to an object by another body that is not in direct contact with it. Ex. Gravity, Magnetism
"What is the force exerted by a still liquid on an immersed non-moving object called? -- PressureOtherwise, if the object is moving, one could also have "shear forces".
No. A non-moving object has forces acting on it, but the forces are in balance in such a case.
When balanced forces are applied to a non-moving object, the object remains at rest. This is in accordance with Newton's first law of motion, which states that an object at rest will stay at rest unless acted upon by an unbalanced force.
The friction of a non-moving object is called static friction. It is the force that prevents the object from moving when a force is applied to it.
Drag forces are contact forces, as they act between a solid object and a fluid (such as air or water) that it moves through. The drag force arises due to the interaction between the object and the fluid surrounding it.
A non-contact force is any force applied to an object by another body that is not in direct contact with it. Ex. Gravity, Magnetism
"What is the force exerted by a still liquid on an immersed non-moving object called? -- PressureOtherwise, if the object is moving, one could also have "shear forces".
A force between two particles that is not directed along the line connecting them; for example, a tensor force between two nucleons. anything that is not central force is a non central force. study about central forces to understand this better.
Yes, but the net force is ZERO! If an object is moving at constant velocity, the sum of the forces acting upon it is zero. If at any time the sum of the forces -- sometimes called the net force -- is non-zero, the object will accelerate in the direction of the resultant force.
Non-contact forces are forces exerted on an object by another object which is not in contact with it, a good example being gravitational force.
No, balanced forces acting on an object will not cause it to change its motion. Balanced forces result in no net force, so the object will either remain at rest or continue moving at a constant velocity in a straight line.
The static friction of a non-moving object is called static friction. This type of friction prevents the object from starting to move when a force is applied.
Forces are interactions that cause an object to accelerate or change its motion. They can be either contact forces, such as friction or tension, or non-contact forces, such as gravity or electromagnetic forces. Understanding forces is essential in explaining how objects move and interact with each other.