If the distance between the centres of the atoms of potassium and bromine in KBr (potassium - bromide) molecule is `0.282xx10^(-9)`m, find the centre of mass of this particle system from potassium (mass of bromine = 80 u, and of potassium = 39 u).

Explanation

Mass of bromine, `m_(Br)=80` units
Mass of potassium, `m_(K)=39` units
Position co-ordinate of potassium, `x_(k)=0`
Position co-ordinate of bromine, `x_(Br)=0.282xx10^(-9)m`

`:.` Position co-ordinate of centre of mass,
`x_(c)=(m_(k)x_(k)+m_(Br)x_(Br))/(m_(k)+m_(Br))`
`x_(c)=(39xx0+80xx0.282xx10^(-9))/(39+80)`
`impliesx_(c)=0.189xx10^(-9)m`