ma=50
mb=150

Plot[{((2*mb)/(ma+mb))*Sin[2Pi*2*t]* Sin[2Pi*100*t],Cos[2Pi*2*t]*Cos[2Pi*100*t]+((mb-ma)/(ma+mb))*(Sin[2Pi*2*t]*Sin[2Pi*100*t])},{t,0,0.5}, PlotLabel->"COORDENADAS NORMALIZADAS \n(fpro=100 Hz  fmod=2 Hz  mb=150g ma=50g)",PlotLabels->{"♆a","♆b"},AxesLabel->{"t","♆"}]

m=50
Plot[{(1/4)(m/1000)*(((2Pi*100))^2)*((Sin[2Pi*2*t])^2),(1/4)(m/1000)*(((2Pi*100))^2)*((Cos[2Pi*2*t])^2)},{t,0,0.5}, PlotLabel->"ENERGIA CINETICA MEDIA \n(ma=mb)",PlotLabels->{"<Ta>","<Tb>"},AxesLabel->{"t","<T>"}]

ma=10
mb=1
Plot[{(ma/1000)*((((mb/(ma+mb))))^2)*(((2Pi*100))^2)*((Sin[2Pi*2*t])^2),(mb/4)*((((2Pi*100))^2)*((Cos[2Pi*2*t])^2)+(((((mb-ma)/(ma+mb))))^2)*(((2Pi*100))^2)*((Sin[2Pi*2*t])^2))},{t,0,0.5}, PlotLabel->"ENERGIA CINETICA MEDIA \n(ma>>mb)",PlotLabels->{"<Ta>","<Tb>"},AxesLabel->{"t","<T>"}]