Intuitive concept of force

Objects and systems move due to the application of forces. First, let us define what is the concept of force. To begin with, let us define force intuitively as a push or a pull. Generally speaking, the magnitude and direction of a push or pull, which are both vector quantities, can vary significantly in each direction. If a cannonball is launched into the air by a cannon, it exerts a powerful force. By contrast, Earth exerts a very small downward pull on a flea. We can also see how multiple forces add to our everyday lives. 

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Intuitive concept of force

A force exists when two objects interact. These interactions can be physical or non-physical. Physical forces such as pulling a rope or hitting a ball with a bat involve physical interaction, while non-physical forces such as magnetic force, electrostatic force, etc., do not.

In addition to magnitude, a force also has direction. A force’s magnitude is its power. It is important to specify both the direction and magnitude when determining a force since magnitude and direction might change its effects.

Types of Forces

 In the concept of force and motion forces can be classified into two types:

• Contact Forces

• Non-contact Forces

Contact Forces

The term ‘Contact Force’ refers to any force that requires that another object is in contact with it. These forces are also known as mechanical forces. There are different types of these forces as described below:

Muscular Forces

Muscular force is the result of muscle action. The force can only exist when an object is in contact with it. In our everyday life, we do many tasks by using this force such as picking up a ball, throwing a stone, pushing, or pulling an object. 

Frictional Forces

A frictional force acts on an object when it starts moving. As a result of a surface being moved or when an object is moved, it creates a resisting force. A frictional force is produced when two surfaces come into contact. Examples include stopping a moving car with friction or writing on paper by pen.

Normal Force

Let a notebook be placed stationary on a table. Since it is pulling downward due to gravity so there is another force in the upward direction so that it will be stationary on the table. This upward force is called Normal force.

Applied Force

The force applied by pushing the table across the room acts on another object when it comes in contact. In this case, it is ‘applied force’; that is, a force applied to someone or something.

Tension Force

A fully stretched cable or wire is tensioned when attached to an object. Due to this, both directions exert equal pressure and cause a tension force.

Spring Force

An elongated or compressed spring exerts a force known as a spring force. As a result of the spring’s attachment, the force could be either a push or a pull.

Non – contact Forces
Normally, non-contact forces act through spaces without direct contact with the body.

The following are examples of non-contact forces:

• Gravitational Force

• Electrostatic Force

• Magnetic Force

A magnet exerts a magnetic force upon other magnets. Since they are non-contact forces, magnetism and electrostatics act on objects from a distance, an object that falls to the ground is attracted to the Earth by gravity, an attractive force. Earth’s gravitational pull pulls a body’s weight towards its center.

Various Effects of Force

Here are five effects of force, each with an example:

• Even a stationary object can be moved by force 

Forces tend to move stationary objects in the direction of the force applied to them. An object such as a stationary tennis ball will continue to move in the direction of a force applied to it.

• Forces can slow or stop moving objects

If an object is moving, force must be applied either to stop it or slow it down. Applying external force to the moving ball, for instance, can stop the motion.

• Changes the direction of moving bodies/objects by applying force

An external force can be applied to any moving object to change its direction. By applying force at an angle, you can change the direction of a moving football.

• Can also change an object’s shape by applying force 

The shape of a rod can be changed by hammering it because external forces are being applied to the rod.

• An object can be changed in speed by using force

By pedaling the pedal of the bicycle, we increase its speed. We reduce the speed of the bicycle by applying the brakes.

Properties of Resultant Force

Changing the velocity of an object depends on the resultant force.

• Objects under balanced forces have a resultant force equal to zero.

• The object will always remain stationary if the acting force is ‘zero’. If the object moves in a straight line at a steady speed, it is said to move steadily.

• The object is said to be decelerated or accelerated if the acting force on the object is not zero.

Magnitude of Force

Precision, which is of force, is important for many reasons, for example, determining engine thrust, weighing structures, and assessing materials. The force of magnitude measures:

1.  A Newton is defined by the SI system as the force required to accelerate one kilogram at a rate of one meter per second, per second.

2.  “The pound” is in the British or American system.

Concept of force and inertia

It is Newton’s first law of motion that states, “An object at rest will remain so until an unbalanced force acts upon it.” Objects tend to “keep doing what they’re doing.” It is the nature of objects to resist changes in the state of motion. This tendency to resist change is known as inertia.

Conclusion

In our everyday lives, we see the different effects of force all the time. Walking, running, playing, sitting, and even standing are common movements we make every day. The motion of the state has changed in all of these activities. Some used objects are being brought to rest or brought to motion. Generally speaking, the magnitude and direction of a push or pull are both vector quantities and can vary significantly in each direction. A force’s magnitude is its power. When determining the concept of force, it is important to specify both the direction and magnitude since magnitude and direction might change its effects.