What is Kinetic energy? Derive an expression for kinetic energy.
Answers
Answer:
The kinetic energy 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. Consider a body of mass "m" starts moving from rest. After a time interval "t" its velocity becomes V.
Answer:
Kinetic energy 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.
Consider a body of mass "m" starts moving from rest. After a time interval "t" its velocity becomes V.
If initial velocity of the body is Vi = 0 ,final velocity Vf = V and the displacement of body is "d". Then
Derivation for the equation of Kinetic Energy:
The relation connecting the initial velocity (u) and final velocity (v) of an object moving with a uniform acceleration a, and the displacement, S is
v^2 - u^2 = 2aS
This gives
S = ½a(v^2 - u^2)
We know F = ma. Thus using above equations, we can write the workdone by the force, F as
W = ma × ½a(v^2 - u^2)
or
W =m( v^2 - u^2 ) ½
If object is starting from its stationary position, that is, u = 0, then
W = ½mv^2
It is clear that the work done is equal to the change in the kinetic energy of an object.
If u = 0, the work done will be W = ½mv^2
Thus, the kinetic energy possessed by an object of mass, m and moving with a uniform velocity, v is Ek= ½mv^2