When the net force equals zero?

Answer 1

A net force of zero means that an object behaves as if there are no forces acting upon it, although this may not be the case. Usually objects have many forces acting upon them. Just your computer that is sitting on your desk is experiencing a force of gravity, the force from the table pushing up on the computer, a frictional force holding the computer in place, etc. We can add the effects of these forces to determine one force that produces the same effect as every force that acts upon the object. This is called the principle of superpostion, which states that every force can be added to other forces to find a single net force. In the case of the computer, the force of gravity is cancelled out by the force of the table pushing up on the computer. So far we have zero force. The force of friction will resist any force that you exert upon the computer, so that force is also zero. As long as your computer is at rest and not sliding across the table, it is experiencing zero net force, while there are really many forces acting upon it.

Answer 2

This is not really a question, but to explain what it means is what I will do.

A net force (FNET) of 0 means that all forces are cancelling each other out. THIS DOES NOT MEAN THAT AN OBJECT IS NOT MOVING.

All a FNET means is that an object is not accelerating. The object can still be moving as a constant acceleration means a constant velocity.

A very simple, but not the only, example of this is an object thrown horizontally. Once the object is released, there is no force making it accelerate so it remains at a constant velocity with 0 m/s^2 as an acceleration, ignoring air resistance.

Ex: ball is thrown horizontally at 20 m/s. This number will not change because once the ball leaves the man/woman's hand, the ball has nothing propelling it in the horizontal direction any longer. therefore, the ball will remain at 20 m/s in the x-axis direction until it comes in contact with something else or air resistance (if it is there) slows it down to a point where it is not accelerating any longer.

Answer 3

When the net force on an object is zero, then the speed and direction of the object's motion

don't change.

The object can certainly be moving, even at a high rate of speed. That doesn't require any force.

But without force, the speed and its direction can't change. The object continues moving at a

constant speed, in a straight line.

Answer 4

When the net force acting on a body is zero the total work done on the body by all the forces acting on it is also zero for any displacement. But the work done by individual forces are non zero (provided there's some displacement and it's component in the direction of forces exist), only their sum is zero.

The work done by a force(F) for a particular displacement(S) is dot product of the two. Now as long as the displacement is non zero and has a component in the direction of the force work by that force is non zero(can be positive or negative).

We can imagine a situation of a small wood block moving on a horizontal table. There will be friction opposing it's motion, if we supply another force which is equal in magnitude but opposite in direction(i.e. along direction of motion) to friction then the two forces cancel out and net force on body becomes zero and total work done is zero. But individually forces are doing work. Work by friction is negative and by our given force is positive and sum of them is zero. Same is case for all bodies in uniform motion. bodies in uniform motion have net force zero. There can be some forces acting on the body whose resultant is zero or there can be no force acting on the body.

It is not necessary that if total work is zero then net force is zero as is the case of uniform circular motion in which net force is non zero but work is zero.

Answer 5

Nothing. When the net force is zero, the object will not accelerate because their is no resultant force acting on the object.

Answer 6

No acceleration of the system will occur (there may be acceleration happening to individual components within the system, but the system itself, will have a net nothing acceleration).