A lava flow is threatening to engulf a small town. A 550-m-wide, 30-cm-thick tongue of 1200âC lava is advancing at the rate of 1.0 m per minute. The mayor devises a plan to stop the lava in its tracks by flying in large quantities of 20âC water and dousing it. The lava has density 2500 kg/m3,specific heat 1100 J/kgâK, melting temperature 800âC, and heat of fusion 4.0 Ã 105 J/kg How many liters of water per minute, at a minimum, will be needed to save the town?