Solved step by step with explanation: find the equilibrium temperature on the upper surface of the car.

To find the equilibrium temperature on the upper surface of the car, we need to consider the heat balance between the absorbed solar radiation and the heat dissipated through convection.

First, let's convert the speed of the train from kilometers per hour (km/h) to meters per second (m/s):

Solar radiation = 380 W/m^2

Area = width * length = 2.8 m * 8 m = 22.4 m^2

Since the car roof is perfectly insulated, we can assume that there is no heat transfer coefficient, and the heat dissipated through convection is negligible. Therefore:

Q_dissipated ≈ 0 W

Since the heat dissipated through convection is negligible, there is no heat loss, and the absorbed solar radiation remains on the car roof. This implies that the equilibrium temperature of the upper surface of the car will continue to rise indefinitely.

However, it's important to note that in a realistic scenario, heat dissipation through convection and other heat transfer mechanisms would prevent the temperature from increasing indefinitely.