A 1 kg block of metal at 100°C is placed in 2 kg of water at 20°C. Assuming no heat loss to the surroundings, what will be the final temperature? (Specific heat of water = 4.2 kJ/kg°C) (2022)
Practice Questions
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Q1
A 1 kg block of metal at 100°C is placed in 2 kg of water at 20°C. Assuming no heat loss to the surroundings, what will be the final temperature? (Specific heat of water = 4.2 kJ/kg°C) (2022)
25°C
30°C
35°C
40°C
Using the principle of conservation of energy, set heat lost by metal equal to heat gained by water to find the final temperature.
Questions & Step-by-step Solutions
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Q
Q: A 1 kg block of metal at 100°C is placed in 2 kg of water at 20°C. Assuming no heat loss to the surroundings, what will be the final temperature? (Specific heat of water = 4.2 kJ/kg°C) (2022)
Solution: Using the principle of conservation of energy, set heat lost by metal equal to heat gained by water to find the final temperature.
Steps: 7
Step 1: Identify the mass and initial temperature of the metal block. The mass is 1 kg and the initial temperature is 100°C.
Step 2: Identify the mass and initial temperature of the water. The mass is 2 kg and the initial temperature is 20°C.
Step 3: Use the formula for heat transfer: Q = mcΔT, where Q is heat, m is mass, c is specific heat, and ΔT is the change in temperature.
Step 4: Set up the equation for heat lost by the metal: Q_metal = m_metal * c_metal * (T_initial_metal - T_final).
Step 5: Set up the equation for heat gained by the water: Q_water = m_water * c_water * (T_final - T_initial_water).
Step 6: Since no heat is lost to the surroundings, set the heat lost by the metal equal to the heat gained by the water: Q_metal = Q_water.
Step 7: Substitute the known values into the equation and solve for T_final, the final temperature.
