Questions: Two friends bought phones that cost different amounts but had identical batteries. After using the phones for a while, both friends had to turn them off to let the batteries cool. This table shows how the temperature of each battery changed over 5 minutes. Battery Initial temperature (°C) Final temperature (°C) Battery in the less expensive phone 35 22 Battery in the more expensive phone 35 25 During this time, thermal energy was transferred from each battery to the surroundings.

Solution Steps

We are given the initial and final temperatures of two identical batteries in different phones. The task is to analyze the temperature change over a 5-minute period.

For each battery, calculate the change in temperature:

• Battery in the less expensive phone: \[ \Delta T_1 = \text{Initial temperature} - \text{Final temperature} = 35^\circ \text{C} - 22^\circ \text{C} = 13^\circ \text{C} \]

• Battery in the more expensive phone: \[ \Delta T_2 = \text{Initial temperature} - \text{Final temperature} = 35^\circ \text{C} - 25^\circ \text{C} = 10^\circ \text{C} \]

The temperature change indicates the amount of thermal energy transferred from each battery to the surroundings. A larger temperature drop suggests more energy was transferred.

• The battery in the less expensive phone experienced a larger temperature drop (\(13^\circ \text{C}\)) compared to the battery in the more expensive phone (\(10^\circ \text{C}\)).

Final Answer