FORCE & significance in daily life

So let's start with...

• WHAT is Force ??

  • Force is an external agent that has the ability to change the state of rest or motion of a specific body.

  • It is Vector quantity i.e that it has magnitude as well as direction.

  • Aristotle characterized force as something which causes an entity to move in a “unnatural motion.”

  • It can also be described as a push & pull on an object.

Fig.1 PUSH

Fig.2 PULL

here, as you can see in Fig.1., where a person is pushing the box to move it, here the box starts to move the moment the pushing force applied by the person exceeds the weight of the object.

The same is the case in Fig.2., where the owner is trying to pull his dog who is tied with a rope belt, the start to move towards the dog only when the pull force exerted by the owner exceeds the weight of the Dog.

• · WHAT units are used to measure Force??

  • S.I Unit : kg.m /s2 ( Newton )

  • CGS Unit : dyne

• WHICH instruments/measuring device is used to measure Force ??

  1. Mechanical Gauge - Spring Scale

  2. Digital Gauge

  • Digital Gauges consists of various types of Load Cells such as:

1. Hydraulic Load Cell

2. Pneumatic Load Cell

3.Strain Gauges, etc.

Now you must be wondering what is the difference between Load cell& Strain Gauges, we got that answer for you.

The most important contrast is that a strain gauge is a single resistive element, while a load cell is an arrangement of four strain gauges in a Wheatstone bridge configuration. Also using a load cell involves applying voltage to opposite nodes, whereas using a strain gauge necessitates arranging two to four strain gauges to undergo opposite forces.

Fig.3 Spring Scale

Fig.4 Hydraulic Load Cell

Fig.5 Strain Gauge

• WHAT types of Force are there ??

  • Muscular Force

  • Mechanical Force

  • Frictional Force

  • Gravitational Force

  • Electrostatic Force

Let's see the importance of each force mentioned above with their application..

1. WHAT is Muscular Force & significance/application of Muscular force ??

   • Muscular force is the force applied using parts of the body like arms or legs.

   • Muscular force is found in all human beings, animals, birds, insects.

   • This force is mainly used to push, pull, lift, throw an object but by means of the physical strength of human beings, animals, birds, insects.

   • It consists of activities such as pushing a box, pulling a rope, pulling of the cart by animals, lifting books from the floor and carrying them, lifting up dumbells, weights for exercise, etc.

Fig.6 A Horse pulling a cart

Fig.7 A Girl cycling

Fig.8 A Girl carrying books with her Hands

Fig.9 A Boy exercising using Dumbells

All such activities wouldn't have been possible if Muscular Force would have been absent.

2. WHAT is Mechanical Force & the significance/application of Mechanical force ??

• A mechanical force is described as a force that involves some physical interaction between two objects (one applying the force and another that is at rest or in motion) and leads to changes in the state of the object (state of rest or state of motion).

• eg: A pulley is used to fetch water from the well. Here the person is using his muscular force to pull out the water from the well but that isn't sufficient to get to do so there's a Pulley attached on the top well which induces Mechanical Force and makes it easy for the person to draw out water from the well using rope and pulley arrangement.

• Other examples also include hammering of screws, Opening door attached to a hinge, etc.

Fig.10 A Girl drawing out water from well

Fig.11 Opening Door

3. WHAT is Frictional Force & significance/application of Frictional force ??

• Frictional force refers to the force generated by two surfaces that contacts and slide against each other.

• Factors affecting the frictional force are:

  • These forces are mainly affected by the surface texture and amount of force impelling them together.

  • The angle and position of the object affect the amount of frictional force.

• Frictional Forces can be desirable as well as undesirable depending on where the forces are acting.

• For instance, when a car is being driven there needs to be some friction/frictional force acting between the tyres and the tarmac which will allow the wheels to rolls over rather than sliding. And also during breaking the friction between tyres and tarmac would result in the appropriate stopping of the car rather than Skidding and dashing away.

• But if there is a frictional force/ friction present in the hinges of the door it would lead to a quaking sound whenever the door is opened/closed. This certainly undesirable as this would lead to damage to the hinge as well as it will be unpleasant to ears.

Fig.12 Friction acting on wheels of Automobile

4. WHAT is Gravitational Force & significance/application of Gravitational force ??

• Each body in this universe attracts other bodies towards itself with a force known as Gravitational Force.

• According to Newton’s law of gravitation, "Every particle in the universe attracts every other particle with a force whose magnitude is, a)Directly proportional to the product of their masses & b) Inversely proportional to the square of the distance between their centre."

• Eg:

  • The force that causes a car to coast downhill even when you aren't stepping on the gas.

  • The force that causes a ball you throw in the air to come down again.

  • The force that causes the moon to revolve around the Earth.

  • The force that keeps you walking on Earth instead of floating away into space.

Fig.13 An Apple falling down from tree.

Fig.14 A child jumping.

5. WHAT is Electrostatic Force & significance/application of Electrostatic force ??

• The electrostatic force is an attractive and repulsive force between particles are caused due to their electric charges.

• The electrostatic force is governed by Coulomb's Law.

• Coulomb's law states that the electrostatic force between two point charges is directly proportional to the product of charge and inversely proportional to the square of the distance between them.

• Eg:

  • The attraction of paper to a charged scale by rubbing to hair.

  • Photocopier & laser printer operation, etc.

Fig.15 Electrostatic force

So we can conclude that there are different types of forces in nature that are necessary for our daily activities. it enables us to do our daily chores, making physical health, transportation, etc. Can you imagine a day when gravity just ceases what would happen ??? Well, we might all just float here and there, won't be able to walk properly. Imagine Frictional force/ friction being absent while you are driving your vehicle might just slide and not stop until it ends up crashing up as brakes will be applied but due to lack of friction, the wheels just won't stop instead slide and dash someone/somewhere. The most important part in offices "printers" would stop working if electrostatic force wouldn't be present.

Sir Issac Newton also quoted "When two Forces unite, their efficiency Doubles". This can be seen clearly in the example of 'A man drawing water from well using a pulley and rope' arrangement. Here the water could have been drawn easily using the muscular force of man but it would have been difficult to do so. But when the Muscular force of man is combined with Mechanical force generated by Pulley it became easy to draw out to the water from the well. We can end here on a lighter note "May the Force be with you." 😂