<p>A water heater of power 2000W&nbsp; &nbsp;is used to heat water. The specific heat capacity of water is 4200 J&nbsp;<span class="equation">\(kg^{-1}K{-1}\)</span> &nbsp; . The efficiency of heater is 70%. Time required to heat&nbsp; 2 kg of water from&nbsp;<span class="equation">\(10^0C\)</span>&nbsp;to&nbsp;<span class="equation">\(60^0\)</span>​​​​​​​C &nbsp;is _________ s</p>

<p>(Assume that the specific heat capacity of water remains constant over the temperature range of the water).</p>