Forces and Motion
Forces are omnipresent and are responsible for a lot of activities in our daily lives. When you ride a bicycle, go in bus, travel in airplane or even just sit or stand...Forces are all around us.. An understanding of forces provides us with greater depth of knowledge about our universe..
Have you ever asked yourself these questions?
1. Why am I able to "SIT" on a chair?
2. Why is it difficult to walk on slippery floors?
3. Why do things break?
The answer to all the above questions lies in the omnipresent "FORCE"... So here we go...
"MAY THE FORCE BE WITH YOU"
What is Force?
Force is a disturbance which results in motion or tendency of motion. Please understand that while you may be pushing a heavy box, it may not move. The force applied by you is insufficient to overcome another force of resistance of motion called as friction which we will study in more detail later. Hence Force results in tendency of motion. Actual motion depends on overall sum of forces acting on the body.
Force is a vector quantity, which means it has both magnitude and direction. This is pretty simple to understand. A body will move in the direction of application of force.
What did Newton talk about Force and Motion?
Newton gave the far-reaching principles of mechanics which have shaped the world today. His laws define the way all our automobiles and machines work. Had he not theorised and discovered these fundamental principles we would still be using horses to travel ! So Newton gave 3 fundamental principles related to motion.
1. A body continues in its state of rest or in its state of 'uniform motion', unless a force is applied on it.
2. The rate of change of momentum is directly proportional to the Force applied on the body and this change takes place in the direction in which the force is applied.
3. To every action there is an equal and opposite reaction
What are the implications of First Law of Motion?
First law talks in principle about the inherent property of any system / body to resist a change in 'state'. A body in rest would prefer to be at rest, and one in uniform motion would continue doing so. As soon as we apply a force, it acts as a stimulus for change of state.
- A body at rest would acquire tendency for motion
- A body in motion would either start moving faster or slower than before (depending on the direction which the force is applied)
This resistance to change is known as inertia. It is precisely here that we can recognise that a heavier body would have a higher resistance to change than a lighter body. Thus inertia of a body is directly proportional to the mass of the body.
Please always remember, that first law gives the concept of inertia and then links it to mass. As soon as we start bringing 'mass' into picture, we begin to understand that mass does affect motion of a body.
What are the implications of Second Law of Motion?
The second law is probably the single most important principle in classical mechanics. It derives a direct linkage between 'Force' and 'Speed of Motion', using the concept of inertia or mass.
As Rate of change of momentum is proportional to Force we can do the following:
Let Force = F ; Mass = m ; Initial velocity = v1 ; Final velocity = v2; Time of application of force = t
Hence F = (m (v2 - v1) ) / t (We assume a proportionality constant of 1)
Now (v2 - v1) / t is rate of change of velocity which is termed as acceleration.
Hence we can replace (v2 - v1) / t by 'a' or acceleration.
Therefore F = m a ...
- Principle of conservation of momentum follows directly from the second law of motion. Any system where the net force is zero will not see any change in momentum.
TO UNDERSTAND FORCES MORE VISUALLY CLICK ON THE BELOW:
CLICK HERE
Forces are omnipresent and are responsible for a lot of activities in our daily lives. When you ride a bicycle, go in bus, travel in airplane or even just sit or stand...Forces are all around us.. An understanding of forces provides us with greater depth of knowledge about our universe..
Have you ever asked yourself these questions?
1. Why am I able to "SIT" on a chair?
2. Why is it difficult to walk on slippery floors?
3. Why do things break?
The answer to all the above questions lies in the omnipresent "FORCE"... So here we go...
"MAY THE FORCE BE WITH YOU"
What is Force?
Force is a disturbance which results in motion or tendency of motion. Please understand that while you may be pushing a heavy box, it may not move. The force applied by you is insufficient to overcome another force of resistance of motion called as friction which we will study in more detail later. Hence Force results in tendency of motion. Actual motion depends on overall sum of forces acting on the body.
Force is a vector quantity, which means it has both magnitude and direction. This is pretty simple to understand. A body will move in the direction of application of force.
What did Newton talk about Force and Motion?
Newton gave the far-reaching principles of mechanics which have shaped the world today. His laws define the way all our automobiles and machines work. Had he not theorised and discovered these fundamental principles we would still be using horses to travel ! So Newton gave 3 fundamental principles related to motion.
1. A body continues in its state of rest or in its state of 'uniform motion', unless a force is applied on it.
2. The rate of change of momentum is directly proportional to the Force applied on the body and this change takes place in the direction in which the force is applied.
3. To every action there is an equal and opposite reaction
What are the implications of First Law of Motion?
First law talks in principle about the inherent property of any system / body to resist a change in 'state'. A body in rest would prefer to be at rest, and one in uniform motion would continue doing so. As soon as we apply a force, it acts as a stimulus for change of state.
- A body at rest would acquire tendency for motion
- A body in motion would either start moving faster or slower than before (depending on the direction which the force is applied)
This resistance to change is known as inertia. It is precisely here that we can recognise that a heavier body would have a higher resistance to change than a lighter body. Thus inertia of a body is directly proportional to the mass of the body.
Please always remember, that first law gives the concept of inertia and then links it to mass. As soon as we start bringing 'mass' into picture, we begin to understand that mass does affect motion of a body.
What are the implications of Second Law of Motion?
The second law is probably the single most important principle in classical mechanics. It derives a direct linkage between 'Force' and 'Speed of Motion', using the concept of inertia or mass.
As Rate of change of momentum is proportional to Force we can do the following:
Let Force = F ; Mass = m ; Initial velocity = v1 ; Final velocity = v2; Time of application of force = t
Hence F = (m (v2 - v1) ) / t (We assume a proportionality constant of 1)
Now (v2 - v1) / t is rate of change of velocity which is termed as acceleration.
Hence we can replace (v2 - v1) / t by 'a' or acceleration.
Therefore F = m a ...
- Principle of conservation of momentum follows directly from the second law of motion. Any system where the net force is zero will not see any change in momentum.
TO UNDERSTAND FORCES MORE VISUALLY CLICK ON THE BELOW:
CLICK HERE
