Suppose that the laptop of Prob. 2.16 is placed in an insulating briefcase with a fully charged battery, but it does not go into “sleep” mode, and the battery discharges as if the laptop were in use. If no heat leaves the briefcase, the heat capacity of the briefcase itself is negligible, and the laptop has a mass of 2.3 kg and an average specific heat of 0.8 kJ⋅kg⁻¹⋅°C⁻¹, estimate the temperature of the laptop after the battery has fully discharged.

Problem 2.16

The battery in a laptop computer supplies 11.1 V and has a capacity of 56 W ⋅ h. In ordinary use, it is discharged after 4 hours. What is the average current drawn by the laptop, and what is the average rate of heat dissipation from it? You may assume that the temperature of the computer remains constant.