# Thermal Equilibrium: Why Does Car Get Hotter Inside?

• nmsurobert
In summary, the glass blocks the shorter-wavelength radiation (infrared and visible light) from the outside, which makes the inside of the car warmer than the outside. The same thing happens with anything you leave out in the sunlight - the sun warms it, then it warms the air it is touching. The car would stop heating once it reached the same temperature as the outside, but we're able to survive because the atmosphere keeps the heat trapped.

#### nmsurobert

So you take some boiling water and drop a metal cube into it and the cube will reach the temp of the water. Or you leave some hot water out on a desk and the water will eventually become room temperature, right?

Then why, in the summer time, does the inside of the car get way hotter than the temperature outside of it?

One reason to get hotter on sunny day is that the Sunlight of lower wavelength gets trapped in and then due to the fact that now higher wavelength EM Waves cannot go out and hence temperature inside gets higher(greenhouse effect).

Oh ok. It must be something beyond my current physics knowledge then because that explanation didn't help much haha not insulting you just saying I'm not at that level.

nmsurobert said:
Then why, in the summer time, does the inside of the car get way hotter than the temperature outside of it?

Sunlight shines in through the glass, heating the seats and the dashboard and whatever else it shines on. These then heat the air next to them, and the inside of the car gets warmer. It's no different than running the car's heater to warm up the air in the car - as long as the heater is going, the interior will be warmer than the outside.

The same thing happens to anything you leave out in the sunlight - the sun warms it, then it warms the air it is touching. You just notice it much more with the car because the closed windows keep the air trapped inside the car so the heat can build up.

But why doesn't the car stop heating once it's at the same temperature as the outside. That's what I'm hung up on.
I didn't think to compare it to the green house effect. I'll do some reading on it to make sense of it now that I know that.

Glass does not allow the inner heat(infrared EM radiation of longer wavelength) to pass and hence internal energy of inside increases.
I think it may also be in conformity with adiabatic process.
Why we are able to survive on the Earth is also due to the effect of greenhouse as the atmosphere keeps heat trapped.
Now if your question is why glass does that, it needs to be enquired.

## What is thermal equilibrium?

Thermal equilibrium is a state in which two or more objects or substances have reached the same temperature and there is no net flow of heat between them.

## Why does a car get hotter inside?

A car gets hotter inside because it absorbs heat from the sun and its surroundings, and the heat is unable to escape due to the insulation properties of the car's interior. This causes an increase in the car's internal temperature until it reaches thermal equilibrium with its surroundings.

## How does thermal equilibrium affect the temperature inside a car?

Thermal equilibrium determines the final temperature inside a car. If the car's surroundings are hotter, the car will absorb heat and become hotter inside. If the surroundings are cooler, the car will release heat and become cooler inside until it reaches equilibrium.

## What factors can affect thermal equilibrium inside a car?

The main factors that can affect thermal equilibrium inside a car are the outside temperature, the insulation properties of the car's interior, and any sources of heat or cooling inside the car, such as air conditioning or heated seats.

## How does thermal equilibrium impact the efficiency of a car's air conditioning?

Thermal equilibrium plays a crucial role in the efficiency of a car's air conditioning system. If the car's interior is significantly hotter than the desired temperature, the air conditioning will have to work harder to cool it down, resulting in decreased efficiency and increased fuel consumption. This is why it is recommended to park a car in the shade or use a sunshade to prevent excessive heat buildup inside the car.