USA: +1-585-535-1023

UK: +44-208-133-5697

AUS: +61-280-07-5697

Kinetic Energy

The kinetic energy is defined as T = 1/2 mv2. This is the total work done on the particle to bring it from state of rest to a velocity v . The S.I. unit of K.E. is N-m or Joule. K.E. is always positive whether vis positive or negative.


From equation (6.2), we can write

U1 -2 = T2 –T1

where              T2 = 1/2 mv22

and                   T1 =1/2 mv12

U1-2 = T2 –T1 = ∆T

Equation {6.3) is the work-energy equation. Equation (6.3) states that total work done

during change of state 1 to 2 is equal to the net change in kinetic energy.

Equation (6.3) can be written as


T1 +U1-2 = t2


Equation {6.4) states that kinetic energy at state 1 plus the work done during 1 -2

is equal to the kinetic energy at state 2.