An electric heater is used to melt a block of ice of mass 1.5kg. If the heater is powered by a 12V battery and a current of 20A flows through the coil, calc...

To melt a block of ice, the heat energy required is given by: Q = mL Where Q is the heat energy, m is the mass of the ice, and L is the specific latent heat of fusion of ice. The power of the electric heater is given by: P = VI Where P is the power, V is the voltage of the battery, and I is the current flowing through the coil. The time taken to melt the block of ice is given by: t = Q/P Substituting the given values: V = 12V I = 20A m = 1.5kg L = 336 x 10^3 J/kg P = VI = 12V x 20A = 240W Q = mL = 1.5kg x 336 x 10^3 J/kg = 504 x 10^3 J t = Q/P = 504 x 10^3 J / 240W = 2100s = 35min (approx) Therefore, the time taken to melt the block of ice is approximately 35 minutes. Explanation: The electric heater converts electrical energy into heat energy. The heat energy produced by the heater is used to melt the ice. The amount of heat energy required to melt a given mass of ice is known as the specific latent heat of fusion of ice. The power of the electric heater is given by the product of voltage and current. Using the formula for heat energy required to melt the ice, and the power of the electric heater, we can calculate the time taken to melt the ice block.