An aluminum electric tea kettle has a mass of 500 g. It has a 500-W heating coil. How long will it take to heat up 1.0 kg of water from 18°C to 98°C in the tea kettle? The specific heat of aluminum is 900 J/(kg·K).

Question

Quizplus · Accepted Answer

To calculate the time it takes to heat the water, we need to use the formula: Q = mcΔT, where Q is the heat energy required, m is the mass of water, c is the specific heat of water, and ΔT is the temperature change.
First, we need to calculate the heat energy required:
Q = mcΔT
= 1000 g × 4.18 J/(g·K) × (98°C - 18°C)
= 314,960 J
Next, we need to calculate the power used by the heating coil:
P = 500 W
Finally, we can use the formula: t = Q/P, where t is the time required to heat the water:
t = Q/P
= 314,960 J / 500 W
= 630 seconds
= 10.5 minutes
So, the best choice is C, 12 minutes.

An Aluminum Electric Tea Kettle Has a Mass of 500