Find the increase in mass when 1 kg of water is heated from `0^@C` to `100^@C` . Specific heat capacity of water `= 4200 J kg^(-1) K^(-1)`.

Explanation

Here ` Q = ms Delta theta `
` = 1 xx 4200 (100 -0)`
` 420000 J`
`E = ( Delta m ) c^(2) `
` Delta m = E / c^(2) = Q / c^(2) = 420000 / ( 3xx 10^(8) ) ^(2) `
` = 42 / 9 xx 10^(4) / 10^(16) = 42 / 9 xx 10^(-12) `
` = 4.66 xx 10^(-12) `
` = 4.7 xx 10^(-12) kg ` .