Kinetic Energy Increases

Kinetic Energy


Kinetic Energy

Many problems in physics require an application of kinetic energy. Kinetic energy is a form of energy that represents the

energy of motion. It is a scalar quantity, which means it has a magnitude but not a direction. It is, therefore, always

positive (as will be evident when we see the equation that defines it).
Deriving Kinetic Energy
Kinetic energy is closely linked with the concept of work, which is the scalar product (or dot product) of force and the.Is this topic Average Kinetic Energy hard for you? Watch out for my coming posts.

displacement vector over which the force is applied.
Using some basic kinematics equations, we obtain an equation for the acceleration of an object which changes speed. (In the

following equation, the term x - x0 has been replaced by s, a term which represents the total distance of displacement.)

v2 = v02 + 2as

therefore,

a = ( v2 - v02 ) / 2s

Applying Newton's Second Law of Motion, F = ma, we get:

F = ma = m ( v2 - v02 ) / 2s

and, multiplying by the distance s (for work) and breaking it apart, we get:

W = Fs = 0.5mv2 - 0.5mv02

The kinetic energy, K (or sometimes Ek) is, therefore, defined as:
K = 0.5mv2
It should be noted that, as mentioned before, this quantity will always be a non-zero scalar quantity. If the object has

mass and is moving, it will always be positive. It will be zero in the case of a massless object or an object at rest (zero

velocity). The kinetic energy equation, therefore, gives us no information about the direction of the motion, only about

the speed.
Work-Energy Theorem
The work-energy theorem comes from the above derivation, and indicates that the work done by an external force on a

particle is equal to the change in kinetic energy of the particle. Mathematically, then, you get:
Wtot = K2 - K1 = delta-K
Using Kinetic Energy
In addition to obtaining the work done, the kinetic energy equation is used frequently in conjunction with other forms of

energy. Due to the law of conservation of energy, we know that the total energy in a closed system will remain constant. Having problem with distance physics formula keep reading my upcoming posts, i will try to help you.

Therefore, analyzing the kinetic energy along with, say, gravitational potential energy allows us to figure out certain

factors of the motion.

End of Kinetic Energy