The ** Net strength ** Is defined as the sum of all the forces acting on an object. An example? When kicking a soccer ball, the ball takes off and moves through the air. At that time, there is a net force acting on the ball.

When the ball begins to return to the ground and finally stops, there is a net force acting on the ball as well. Newton's Second Law states that"when a net force acts on an object, then that object must be accelerated, that is, its velocity changes from second to second." When kicking the soccer ball for the first time, it accelerates, and when the soccer ball begins to slow down to a stop, it is also accelerating.

There may be several forces acting on an object, and when all these forces are added, the result is what we call the net force acting on the object.

If the net force is added to zero, then the object is not accelerating, so it moves with a constant velocity. If the net force is added to a value other than zero, then the object is accelerating.

In nature, all forces oppose other forces, such as friction or opposing gravitational forces. Forces can only produce acceleration if they are greater than the total opposing forces.

If a force pushes an object, but is matched by friction, the object does not accelerate. Likewise, if a force pushes against gravity but is less than the gravitational force on an object, it does not accelerate.

For example, if a 15-Newton thrust on an object is opposed by a 10-Newton friction force, the object accelerates as if it were being pushed by a 5-Newton net force without friction.

** Second law of Newton **

Newton's first law of motion predicts the behavior of objects for which all existing forces are balanced. The first law, (sometimes called law of inertia) states that if the forces acting on an object are balanced, then the acceleration of that object will be 0 m / s / s. Objects in equilibrium (the condition in which all forces are balanced) will not accelerate.

According Newton , An object will only accelerate if there is a net or unbalanced force acting on it. The presence of an unbalanced force will accelerate an object, changing its speed, direction or speed and direction.

** Newton's second law of motion **

This law refers to the behavior of objects for which all existing forces are not balanced. The second law states that the acceleration of an object depends on two variables: the net force acting on the object and the mass of the object.

The acceleration of an object depends directly on the net force acting on the object, and inversely on the mass of the object. As the force acting on an object increases, the acceleration of the object increases.

As the mass of an object increases, the acceleration of the object decreases. Newton's second law of motion can be formally stated as follows:

"The acceleration of an object produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force and inversely proportional to the mass of the object."

This verbal statement can be expressed as an equation as follows:

A = Fnet / m

The above equation is often reordered into a more familiar form as shown below. The net force is equated with the product of the mass multiplied by the acceleration.

Fnet = m • a

Emphasis is always on net strength. The acceleration is directly proportional to the net force. The net force is equal to the mass multiplied by the acceleration. The acceleration in the same direction as the net force is an acceleration produced by a net force. It is the net force that is related to the acceleration, the net force is the vector sum of all the forces. If all the individual forces acting on an object are known, then the net force can be determined.

According to the above equation, a unit of force is equal to one unit of mass multiplied by one unit of acceleration. By replacing standard metric units by force, mass, and acceleration in the above equation, the following unit equivalence can be written.

1 Newton = 1 kg • m / s2

The definition of the standard metric force unit is indicated by the above equation. A Newton is defined as the amount of force required to give a mass of 1 kg and an acceleration of 1 m / s / s.

** Magnitude and equation **

According to Newton's Second Law, when an object accelerates, then there must be a net force acting on it. On the contrary, if a net force acts on an object, that object will accelerate.

The magnitude of the net force acting on an object is equal to the mass of the object multiplied by the acceleration of the object as shown in the following formula:

A net force is the remaining force that produces any acceleration of an object when all opposing forces have been canceled. Opposing forces diminish the effect of acceleration, decreasing the net force of acceleration acting on an object.

If the net force acting on an object is zero, then the object is not accelerating and is in a state we call equilibrium. When an object is in equilibrium, then two things can be true: either the object is not moving at all, or the object is moving at a constant speed. The formula for equilibrium is shown below:

** Examples ** : Consider a hypothetical situation in space. You are doing a space walk and you are fixing something on your ferry. While working on the subject with a wrench, he gets angry and throws the key away, what happens?

Once the key leaves the hand it will continue to move with the same speed that it gave when it launched. This is an example of a zero net force situation. The key will move with the same speed and will not accelerate in space. If you throw the same key on Earth, the key will fall to the ground and finally stop. Why did he stop? There is a net force acting on the key, causing it to slow down and stop.

In another example, let's say you are on an ice rink. He takes a hockey puck and slides it through the ice. Eventually, the hockey puck will slow down and stop, even on smooth and slippery ice. This is another example of a situation with a net force other than zero.

** References **

- The Physics Classroom,. (2016). Newton's Second Law. 11-2-2017, from physicsclassroom.com Website: physicsclassroom.com.
- Cárdenas, R. (2014). What is Net Force? - Definition, Magnitude & Equations. 11-2-2017, from http://study.com Website: study.com.
- IAC Publishing, LLC. (2017). What is net force?. 11-2-2017, from Reference.com Website: reference.com.
- Net force. (N.) Webster's Revised Unabridged Dictionary. (1913). Retrieved February 11 2017 from thefreedictionary.com.
- Pearson, A. (2008). Force and Motion Chapter 5. Force and Motion. 11-2-2017, from Pearson Education Inc Website: physics.gsu.edu.