Respuesta :

Given that,

Mass of water, m = 5 kg

The temperature increases from 20℃ to  40℃.

Specific heat capacity of water is 4200 J kg⁻¹ k⁻¹

To find,

Heat energy required to raise the temperature.

Solution,

The formula for the heat energy required to raise the temperature is given by :

[tex]Q=mc\Delta T\\\\=5\times 4200\times (40-20)\\\\=420000\ J\\\\=420\ kJ[/tex]

So, the heat energy required is 420 kJ.