Kinematics: Understanding Motion in Time and Space - Essay Sample

Introduction

Kinematics originated from the Greek word motion. It is a branch of mechanics that specialize in analyzing the motion of rigid bodies and particles in space; however, from a geometric point of view, it neglects torques and forces that offer a motion. Since the motion of particles happens in time and space, based on classical mechanics, the notion of absolute space and absolute time is introduced. Absolute time denotes consistently changing whose values rise from the past to the future. It is assumed that this quantity is similar at all points of matter. It is uniform and does not rely on the motion of the matter. Absolute space designates a three-dimensional, homogeneous, and isotropic Euclidean space ( Awrejcewicz 187).

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Straight Line (Rectilinear) One-Dimensional Motion

The Motion of a Particle and Trajectory (Path) of Motion

The particle can travels in a straight line or a curved line. The equation of motion of the particle is termed as the trajectory of motion. The velocity of a particle is a vector quantity and describes the direction of the motion of the particle. It also describes the rate of transformation in the position of a particle. And the way it is measured. Acceleration of the particles explains the rate of change of magnitude and the direction of the velocity vector. The velocity increases with time (Awrejcewicz 196). An example in the real world is the motion of a plane, which is referred to as motion in two dimensions. For instance, circular and projectile motion. To analyze such motion, like projectile motion, the reference point will be made in origins such as two points X and Y. projectile motion is an object that travels in a flight after being projected. Acceleration takes place in a straight line and acts in a vertical direction. The equation of motion is explained in the form of the X and Y-axis.

Example

Cricket ball, baseball, and football explain projectile motion. It comprises vertical and horizontal motion, and the gravity aids them. Projectile motion is always in the form of a parabola. | v | = v = ( Vx 2+ vy 2 ), velocity is expressed as

ax = ddt vxay = ddt vythe motion of the plane in a straight line is represented by

v = u+ats = ut+1/2 at2

v2 = u2 + 2as

Projectile motion is determined by assuming the air resistance to make calculations to be easy. The diagram above is a representation of the motion of an object, which is influenced by gravity. This is an instance of projectile motion. An example is a plane in motion. Examples of two-dimensional projectiles are the motion of the earth around the sun, a motion of a boat in a river, a motion of shell fired from a gun, the motion of a billiard ball on the billiard table, and throwing a ball or a cannonball.

Forces & Newton's Laws of Motion

Dynamics refers to the study of forces that causes motion changes in objects. The concept of motion is the physical quantity of force. Force refers to a push or a pull. Forces occur in pairs; it is impossible to have a single force acting. For instance, the interaction of objects is explained in forces. Two bodies will attract one another because of the gravitational force between them. Two electrons will repel one another because they are both negatively charged. Newton's Laws of Motion explain the principle of dynamics. There is three newton's law of motion; the first law of motion explains that a body will remain at rest or in unvarying motion in a straight line unless acted upon by an external force. It describes a statement about inertia that objects will be consistent in motion unless a force acts to change the motion.

This law implicit that the natural state of motion of an object is that it has zero acceleration ( a 0 ), hence, the object is at rest ( v 0 ) or an object can be traveling in a straight line with a steady speed ( v constant ). The behavior of an object to remain at rest or keep moving is called inertia. When the final (net) force acting on a particle is zero, the object is said to be in equilibrium. For example, if someone is standing in a bus moving at a constant velocity when the brakes are held instantly, the person feels that someone has pushed from the back, and you topple forward. However, a person cannot experience a force. By Newton's 1st Law, an individual upper part of the body will continue to move forward while the legs attached to the floor slow down with the bus. Also, when you are standing on a stationary bus, and the bus starts to move forward. Your feet move forward with the bus, but your upper part of the body tends to remain at rest, according to Newton's 1st Law.

The second newton's law of motion states that the acceleration of an object relies on two variables the net force acting upon the object and the weight of the object. The third Newton's law of motion states that for every action, there is an equal and opposite reaction.

Gravity and Friction

Frictional for is the force that two bodies exert on one another; the bodies develop this force when their surface rubs against each other. The factors that influence the force of friction are the types of surfaces that take part and how the two surfaces are pushed against each other. The strength of the friction relies on the type of surface. Sliding friction happens when two surfaces slide over one another. Slide friction enables moving bodies to sow down. With a lack of sliding friction, a penguin that slides down the hill cannot stop until it hit a wall. Static friction occurs in an object that is not moving, for instance, when you are trying pushing a couch in the room, if you do not push hard enough, it will not move. Gravitational force refers to a force that attracts any two objects with mass. Gravitational force pulls masses together; it cannot push them apart. Every object, including the human being, is pulling on every other object in the entire universe. An example is when a person jumps off the plane, he or she falls down due to the effect of gravitational force (Pleasantvalleysd.org 5).

Potential and Kinetic Energy

Kinetic energy (K.E) refers to the energy in motion. The more, the faster a body can move, the more kinetic energy it possesses (K.E=i/2 MV2 or Kgm2/s2). While potential energy (P.E) refers to the energy that a body possessed by virtue of its position relative to others, electric charge, stresses within itself, and other factors (Physics.usyd.edu 5).

The principle of work and kinetic energy referred to as the work-energy theorem, states that the work done by the total number of all forces acting on an object equates to the change in the kinetic energy (K.E) of the particle. If KE decreases, then network W is equal to negative. In other words, this means that when an object slows down, "negative work" has been done on that object. An example is a skydiver's parachute, which makes the skydiver lose KE by slowing him or her down. Work done is given by Wnet = Fnet d cos th, wherein this case, Fnet refers to the net force in the system, d is the displacement of the body, and th is the angle between the force vectors and the displacement ( Fernandez et al. 8).

Momentum - Impulse Theorem

Momentum and impulse describe more about motion and energy. For example, when a golf ball is hit from the ground, a large average force F is enforced in a ball within a short time t, the ball accelerates from the position of rest to a final velocity Vf. It may be hard to evaluate either the force or its time, but their product Ft can be calculated from the resulting change in velocity. Based on Newton's second law, we have F=Ma= m =Vfinal-Vinitial/t. Ft=Mvfinal-V initial. The momentum of a particle is a vector quantity equal in magnitude to the product of its mass m and velocity V P=mv. Hence, impulse = change in momentum (Akindele 1).

Buoyant Force, Archimedes' Principle, Pascal's Law, and Bernoulli's Law

Buoyant force refers to the force that is exerted on the objects that are submerged in a fluid. Archimedes' Principle explains that upward force that is exerted on a body floating in a fluid, whether partially or fully emerged, is equal to the weight of the fluid that the body displaces. Pascal principle states that a pressure alteration at any point in a confined incompressible fluid is transmitted in the entire fluid such that the same alteration happens everywhere. Bernoulli's principle states that when the speed of a fluid increases, it happens simultaneously with a reduction in static pressure or a reduction in the fluid's potential energy. Buoyant and Archimedes principle explains how a boat and ship floats in water (Hep.vanderbilt.edu 5).

Waves

A wave is used to transmit energy or information from one point to another using signals, but no material object makes this journey. Longitudinal waves refer to a kind of wave, in which the movement of the particle is parallel to the motion of the energy. Examples are Pressure Waves and Sound Waves. Transverse waves are when the movement of the particles is at right angles or perpendicular to the motion of the energy. Examples are Electromagnetic waves, Polarized' waves, and Light transverse wave. This explains why and an individual can make a call to a friend in another city with a mobile phone, and the whole communication is happening through audio, but the whole process of transmission of a signal originating from the talker to the receiver occurs as a waveform. The phone change voice into an electrical signal with then propagates either through antennae or copper wires in wireless communication (Byjus.com 6).

Reflection of light occurs when a light traveling in a straight line is reflected after encountering a barrier. The reflected light is parallel if they encounter a smooth surface, and this is referred to as specular reflection. When the reflected surface is rough, the reflected rays are not parallel, and it is known as diffuse reflection. Refraction of light takes place when a ray of light travels through a transparent medium come across a boundary connecting to another transparent medium, a portion of the energy is reflected and some enters to the second medium. The ray that crosses the second medium is bent at the boundary and is known to be refracted. When light passes through a narrow opening, diffraction occurs when light passes through a narrow opening known as slit and is projected on a screen (Uonbi.ac.ke 6). Refraction has several applications in optics and technology. A lens utilizes refraction to form an image of an object for many various purposes, like magnification. A prism utilizes refraction to form a spectrum of colors originating from an incident beam of light.

Doppler Effects

Doppler effects refer to the alternation in the frequency of a wave origin due to relative motion between the observer and the source. This technique is utilized in various fields such as medical diagnosis, traffic management, space technology, and scientific research. An example is a traditional echocardiogram that employs sound waves to emit images of the heart. In this process, a radiologist applies a transducer to relay and receive ultrasound waves, which are reflected when they arrive at the edge of two structures with varying densities.

Atomic Physics and Light

Atom is composed of three particles, protons, nucleus, and electrons. Protons are positively charged, neutrons are neutrally charged, and electrons are negatively charged. Light refers to electromagnetic radiation that the human eye can detect and occurs at a different wavelength. X rays are types of electromagnetic radiation resembling light but have more energy that can enter through objects. Microwave has a wavelength between one meter to one milliliter and frequency, which lies from 300MHZ to 300GHZ. An electromagnetic wave refers to a type of wave which generates...