Final answer:
To prepare the journal entries for the city's street lights, the depreciation expense and accumulated depreciation for the existing street lights should be recorded, and the cost of constructing new street lights should be accounted for.
Step-by-step explanation:
The entries can be prepared as follows:
Depreciation Expense - Street Lights : $30,000 ([$300,000 - $48,000] / 10 years) is debited and Accumulated Depreciation - Street Lights : $30,000 is credited to reflect the depreciation of the street lights over a period of 1 year.
Street Lights (newly constructed) : $78,000 is debited and Cash : $78,000 is credited to reflect the cost of constructing new street lights.
No journal entry is required for the cleaning and repair of the lights as it is considered an expense and not an asset.