previous    next
total kinetic energy

Using the expressions for the velocities of masses m1 and m2, we may determine the total kinetic energy Ekin,total of the system of the two masses.

Ekin,total = ½ m1 v12 + ½ m2 v22

Ekin,total = ½ ( m1 + m2 ) VCM2 + ½ μ v 2


We find one term which expresses the kinetic energy of an object of mass m1 + m2, representing the total mass of the system of two masses, and which travels with the center-of-mass velocity VCM(t) and one term which represents the internal kinetic energy of an object of reduced mass μ, defined by
μ = m1m2 / (m1 + m2)

and with velocity equal to the relative velocity v of mass m2 with respect to mass m1.





next