Question

define a kinetic energy of a object and given its mathematical expression

Answer 1

The energy of an object by its motion is called kinetic energy

The kinetic energy of an object is the energy an object has due to its motion. The formula for kinetic energy is:

KE=1/2 mv^2 , where m is the object’s mass and v is its velocity.

This formula is derived from the work-energy theorem, which states that the amount of work done on an object is equal to the change in its energy. Assuming potential energy is constant, Work is equal to the change in kinetic energy. This is expressed in the formula ∆KE=Fd. You can then use algebra or calculus to derive the kinetic energy equation.

Algebra Derivation:

∆KE=Fd
∆KE=mad (recall that F=ma)

Now, we use the kinematic equation: vf^2-vi^2= 2ad and solve for ad, then we substitute into the original equation.

∆KE=m((vf^2-vi^2)/2)

(vf is final velocity and vi is initial velocity)

We finally expand to get:

∆KE=1/2 mvf^2–1/2mvi^2

This is one of the countless ways to derive the kinetic energy theorem. However, I find this one to be the most beautiful because it is very simple and short.

Answer 2

Energy of a body due to its motion i. Know as the kinetic energy of the body.

If a body has a mass m is moving with a velocity v, than its kinetic energy is given by-
K =1/2mv^2
i.e, k = half*m*(v sqaure)