As I see,I will show you something and I want to explain me who has right. For example into the run a human walk with 5km/h while the train runs with 100km/h,in the same direction. So Newton says: U=V1+V2=5+100=105km/h Einstein,about his law for big speeds says: U=(V1+V2)/(1+(V1*V2)/c^2)=30/(1+(V1*V2)/c^2)= = 30/((c^2/c^2)+(V1*V2)/c^2 )= 30/((c^2+V1*V2)c^2),so to make us 30 needs "((c^2+V1*V2)c^2)" that to make us "1". But it will never will be 1,except If v1 or v2 is zero. So it will be something more than 1. So with einstein theory we will have less than 30(almost 29.xxx) because denominator is more than 1. My question is: Who is correct and why? A guy told me that einstein has the right,because due of speed,(e=mc^2)mass comes bigger,so will go lower at final,so the speed will be less than 30. What you think??? Thank you !!!