Posts

50)Discussed: What to expect on Republic Day 2021and what not to

India Republic Day -- Republic Day 2021: In 2020it was the agitation resistant to the Citizenship Amendment Act (CAA). Nowthousands of farmersmostly from Punjab and Haryanahave been camping at the boundaries of Delhi for more than eight weeksdemanding the Centre repeal the three farm laws. For that second year in a stripRepublic Day celebrations from the national capital will be kept under the shadow of flaming protests against laws handed down by the Centre. In 2020it was the agitation resistant to the Citizenship Amendment Act (CAA). This timethousands of farmersmostly from Punjab and Haryanahave been camping at the boundaries of Delhi for more than eight weeksdemanding the Centre repeal the three farm laws. This specific years Republic Day parade will also be the first major public event in pandemic times. What is new this year The expensive vacation event will be pared down the number of spectatorsthe size of walking in line contingents and other side points of interest. The spe...
Post a Comment
Read more

Kinetic energy

Image
In physics, the kinetic energy ( KE ) of an object is the energy that it possesses due to its motion. It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its acceleration, the body maintains this kinetic energy unless its speed changes. The same amount of work is done by the body when decelerating from its current speed to a state of rest. In classical mechanics, the kinetic energy of a non-rotating object of mass m traveling at a speed v is 1 2 m v 2 {\displaystyle {\begin{smallmatrix}{\frac {1}{2}}mv^{2}\end{smallmatrix}}} . In relativistic mechanics, this is a good approximation only when v is much less than the speed of light. The standard unit of kinetic energy is the joule, while the imperial unit of kinetic energy is the foot-pound.
Post a Comment
Read more

History and etymology

The adjective kinetic has its roots in the Greek word κίνησις kinesis , meaning "motion". The dichotomy between kinetic energy and potential energy can be traced back to Aristotle's concepts of actuality and potentiality. The principle in classical mechanics that E ∝ mv2 was first developed by Gottfried Leibniz and Johann Bernoulli, who described kinetic energy as the living force , vis viva . Willem 's Gravesande of the Netherlands provided experimental evidence of this relationship. By dropping weights from different heights into a block of clay, Willem 's Gravesande determined that their penetration depth was proportional to the square of their impact speed. Émilie du Châtelet recognized the implications of the experiment and published an explanation. The terms kinetic energy and work in their present scientific meanings date back to the mid-19th century. Early understandings of these ideas can be attributed to Gaspard-Gustave Coriolis, who in 1829 publishe...
Post a Comment
Read more

Overview

Energy occurs in many forms, including chemical energy, thermal energy, electromagnetic radiation, gravitational energy, electric energy, elastic energy, nuclear energy, and rest energy. These can be categorized in two main classes: potential energy and kinetic energy. Kinetic energy is the movement energy of an object. Kinetic energy can be transferred between objects and transformed into other kinds of energy. Kinetic energy may be best understood by examples that demonstrate how it is transformed to and from other forms of energy. For example, a cyclist uses chemical energy provided by food to accelerate a bicycle to a chosen speed. On a level surface, this speed can be maintained without further work, except to overcome air resistance and friction. The chemical energy has been converted into kinetic energy, the energy of motion, but the process is not completely efficient and produces heat within the cyclist. The kinetic energy in the moving cyclist and the bicycle can be converted...
Post a Comment
Read more

Newtonian kinetic energy

Image
Kinetic energy of rigid bodies In classical mechanics, the kinetic energy of a point object (an object so small that its mass can be assumed to exist at one point), or a non-rotating rigid body depends on the mass of the body as well as its speed. The kinetic energy is equal to 1/2 the product of the mass and the square of the speed. In formula form: E k = 1 2 m v 2 {\displaystyle E_{\text{k}}={\frac {1}{2}}mv^{2}} where m {\displaystyle m} is the mass and v {\displaystyle v} is the speed (or the velocity) of the body. In SI units, mass is measured in kilograms, speed in metres per second, and the resulting kinetic energy is in joules. For example, one would calculate the kinetic energy of an 80 kg mass (about 180 lbs) traveling at 18 metres per second (about 40 mph, or 65 km/h) as E k = 1 2 ⋅ 80 kg ⋅ ( 18 m/s ) 2 = 12 , 960 J = 12.96 kJ {\displaystyle E_{\text{k}}={\frac {1}{2}}\cdot ...
Post a Comment
Read more

Relativistic kinetic energy of rigid bodies

Image
If a body's speed is a significant fraction of the speed of light, it is necessary to use relativistic mechanics to calculate its kinetic energy. In special relativity theory, the expression for linear momentum is modified. With m being an object's rest mass, v and v its velocity and speed, and c the speed of light in vacuum, we use the expression for linear momentum p = m γ v {\displaystyle \mathbf {p} =m\gamma \mathbf {v} } , where γ = 1 / 1 − v 2 / c 2 {\displaystyle \gamma =1/{\sqrt {1-v^{2}/c^{2}}}} . Integrating by parts yields E k = ∫ v ⋅ d p = ∫ v ⋅ d ( m γ v ) = m γ v ⋅ v − ∫ m γ v ⋅ d v = m γ v 2 − m 2 ∫ γ d ( v 2 ) {\displaystyle E_{\text{k}}=\int \mathbf {v} \cdot d\mathbf {p} =\int \mathbf {v} \cdot d(m\gamma \mathbf {v} )=m\gamma \mathbf {v} \cdot \mathbf {v} -\int m\gamma \mathbf {v} \cdot d\mathbf {v} =m\gamma v^{2}-{\frac ...
Post a Comment
Read more