[Physics Class Notes] on Motion Pdf for Exam

Motion is the change with time of the position or orientation of a body. Everything in this universe is in a state of continuous movement, for example, the motion of animals and humans. Besides this, the basic particle of a matter a.k.a the atom is also in the state of continuous motion too. By this, we mean that every single physical procedure in this universe possesses some type of motion, and the motion either be slow or fast, but it is always present.

You can find objects moving everywhere. The motion of animals and humans are everyday examples of motion. The basic particle of a matter, i.e., the atom is in the state of continuous motion too. Every single physical procedure in this universe is made up of some type of motion. It can be either slow or fast, but the motion is present. However, if a man is snoring, do we say he is in motion or the chirping birds resting on the tree are in motion? If not, then how do we define the movement in an object or a living? 

So, how do you define that there is movement in an object? You identify any movement in the object when you compare its new position from the original position. Any change in the position of the object, with respect to time, is considered to be a motion. There are several things that you can see moving while certain objects like Earth that appear to be still, is also in motion in an actual sense. Everything on Earth that appears still is actually in motion as the Earth itself is in motion (i.e, Rotation and Revolution). This page will help us briefly identify the difference between resting and motion and also the types of motion along with illustrating examples.

How to Identify an Object/Body in Motion?

It’s pretty clear from the above text that we can determine any movement in the object by comparing its new position from the original position. Any change in the position of the object, with respect to time, is considered to be a motion. We find several things that keep on moving like Earth that appears to be still, is always in motion in an actual sense. Everything on Earth that appears still is actually in motion as the Earth itself is in motion (i.e., Rotation and Revolution).

How to Determine if the object is in Motion: Parameters in Motion

An orange fell from a tree, water flowing from the tap, or rattling windows, all these show that the object is in motion. Now, let us see the following important terms that will help us in determining motion:

  • Distance 

  • Speed

  • Displacement

  • Time

Please note that the distance and displacement both help us in describing the change in the object’s position. Also, the distance travelled by an object from point A to point B depends on the type of path it has taken. This means that for an object that takes a circular path, the distance covered by it on this path will be different from the distance covered in the case of a linear path. 

In the case of displacement, it is defined as the shortest distance that connects the two points, P and Q (basically initial and final point). So, let us say P and Q are two cities. The distance between them is ‘d’. Now, when a person moves from city P to city Q and then again returns back to city P, then

()

                  

So, let us say, you are travelling from city P to Q. The distance between them is ‘d’. Now, when you move from city Q and return back to city P, then

Distance travelled = d (P to Q) + d (Q to P)

Displacement = 0, as there is no difference in your initial and final position, i.e, P and P. As you started from P and returned back to P.So, in this case, displacement is nil. 

Besides this, we know that the speed of an object/body is the rate at which the position of the object changes with respect to its origin. It is measured as distance (in meters)/ Time (in seconds) or m/s. This is how we describe the motion of an object. Now, let us go through the types of motion.

Types of Motion

Now, let us talk about the distinctive types of motions that may be seen in an object. These are Linear, Rotary, Oscillating motion, and Periodic motion. Each of these kinds is carried out with an exclusive mechanical means. Let us analyze more about them in detail. 

1) Linear Motion

In linear motion, the object moves from one position to another in either a curved direction or a straight line. On the premise of the type of direction taken by an object, linear motion is similarly categorized as: 

  • Rectilinear Motion – Here, the route taken by an object is a straight line.

  • Curvilinear Motion – Here, the route taken by the object is curved.

One of the nice examples of linear motion is linear actuators in which you could locate cars, cycles, trains, and different cars travelling in a single straight direction. But it will not be referred to as a linear motion whilst the road or rail track is flawlessly circular. You may even locate linear cylinders that display linear motion in pneumatic, hydraulic, and electric options. A linear motion has loads of importance in the field of manufacturing, automation, robotics, etc.

2) Rotary Motion

Rotary motion is a sort of motion in which the object moves in a circle. This kind of motion happens whilst an object rotates at its own place or axis. The rotary motion turned into the first kind of motion that was invented by scientists in primitive times. Some of the examples that could assist you to understand the rotatory motion are:

  • Earth rotating on its own axis about the sun is a nice instance of rotary motion.

  • Another instance is the motion of the wheels and steering wheel of the automobile in the driving state. You will locate that each is rotating around its own axis. The same thing goes with the engine of the automobile because it additionally moves on its own location. Similar to linear cylinders, these days rotary actuators are notably utilized in diverse industries. These cylinders are available for pneumatic, electric, and hydraulic options.

3) Oscillatory Motion

This is the third kind of motion that is characterised by the motion of the item in the form of front and back oscillation. In different words, an oscillatory motion is described as the motion of an object around its mean position. If an object repeats the cycle of its motion after a particular time period, then it far seems like an oscillating motion.

One of the nice examples of oscillating motion is the pendulum of a clock. It repeats its motion after a certain time frame. In an actual sense, the pendulum isn’t displaced from its role. It is stationary in a single position, but it shows motion. Such a kind of recurring motion after a certain time period is known as an oscillating motion.

In this sort of motion, the motion of the object is called oscillation. This is due to the repeated nature of the motion that takes place after a fixed time period. A few different illustrations of an oscillating motion are:

  • When an infant oscillates backwards and forwards around its fixed position at the swing.

  • Table fan is some other instance of periodic motion.

  • Both linear, in addition to a rotary actuator, have oscillating motion.

  • Waves Sound waves are the result of the oscillation of particles.

  • When the cords of the sitar or guitar are struck, then they move backwards and forward approximately their mean position (i.e, oscillatory motion).

4) Periodic Motion

Periodic motion is a kind of motion that is repeated at the same time intervals. A few examples of this motion are a bouncing ball, a rocking chair, a swing in motion, a water wave, a vibrating tuning fork, etc. From the text on motion – types of motion and definition, we understand that motion of an object is the change in orientation/position of a body with respect to time and this change can be slow or fast (speed).

Leave a Reply

Your email address will not be published. Required fields are marked *