Kinetic energy of two moving objects

[malemdk]

Assume a body of mass m moving with velocity V1 towards a body with a mass M and its velocity is zero
The kinetic energy of the first body with respect to the second body is 1/2mV2 in the reference frame fixed to the non moving body
The kinetic energy of the second body with respect to the first body is 1/2MV² in the reference frame fixed to the moving body

There is difference in KE 1/2(M-m)v^2

 

[Doc Al]

There is difference in KE 1/2(M-m)v^2

Do you think that is a meaningful quantity?