A saucepan contains 0.50 kg of water heated from 20°C to 60°C. With c = 4184 J/kg°C, how much energy is added?

Get ready for the NCEA Level 1 Energy Test. Utilize flashcards and multiple choice questions with clear explanations and hints. Prepare for success!

Multiple Choice

A saucepan contains 0.50 kg of water heated from 20°C to 60°C. With c = 4184 J/kg°C, how much energy is added?

Energy to heat a substance comes from multiplying its mass by its specific heat capacity and the change in temperature: Q = m c ΔT. Here, you have 0.50 kg of water, a specific heat capacity of 4184 J/kg°C, and a temperature rise of 60°C − 20°C = 40°C. So the energy added is 0.50 × 4184 × 40 = 83,680 J. That’s the amount of energy required to raise the water by 40 degrees. In context, a 20°C rise would need 41,840 J, and an 80°C rise would need 167,360 J, illustrating how the energy scales with the temperature change.

Energy to heat a substance comes from multiplying its mass by its specific heat capacity and the change in temperature: Q = m c ΔT. Here, you have 0.50 kg of water, a specific heat capacity of 4184 J/kg°C, and a temperature rise of 60°C − 20°C = 40°C. So the energy added is 0.50 × 4184 × 40 = 83,680 J. That’s the amount of energy required to raise the water by 40 degrees. In context, a 20°C rise would need 41,840 J, and an 80°C rise would need 167,360 J, illustrating how the energy scales with the temperature change.

More practice questions