How many kg's in65cm?

Answer 1

The question, as stated, cannot be answered sensibly. A kilogramis a measure of mass, with dimensions [M]. A centimetre is a measure of distance, with dimensions [L]. The two measure different things and basic dimensional analysis teaches that you cannot convert between measures with different dimensions such as these without additional information.

Answer 2

To convert cm to kg, we need more information about the substance being measured. The two units measure different things - cm typically measures length or distance, while kg measures mass or weight.