Question

The heat energy required to raise the temperature of 2 kg of water from 10 °C to 50 °C is (Specific heat capacity of water is 4200 Jkg-1°C-1) [ ] a) 336 x 104J b) 336 x 103 J c) 336 x 102J d) 336 x 10J​

Answer 1

        $\text{Mass of water}(m) = 2 \: kg$

        $\text{Specific Heat Capacity of water}(s) = 4200 \: Jkg^{-1}^{\circ}C^{-1}$

        $\text{Initial Temperature}(t_i) = 10^{\circ}C$

        $\text{Final Temperature}(t_f) = 50^{\circ}C$

$\implies \text{Change in Temperature}(\triangle{t}) = t_f - t_i = 40^{\circ}C$

        $\text{We know that heat energy}(Q) = m\times s \times \triangle{t}$

$\implies \: Q = 2 \times 4200 \times 40$

$\implies \: Q = 336000 \: J$

$\implies \: \boxed{Q = 336\times 10^3 \: J}$