A 3 cu ft ballon is filled with air at 90 degrees F. How many cu ft will that same ballon contain one hour after it is taken into an air conditioned room at 70 degrees F?

To answer this question, we can use the principle of Charles's Law, which states that the volume of a gas is directly proportional to its temperature, assuming the pressure remains constant.

Here's how we can calculate the new volume of the balloon:

1. Start by finding the initial volume of the balloon. Since it is given as 3 cu ft, we'll use this value as the starting point.

2. Next, we need to convert the temperatures from Fahrenheit to Celsius as most gas laws are expressed in terms of Celsius. To convert Fahrenheit to Celsius, subtract 32 from the Fahrenheit temperature and then multiply by 5/9.
- Initial temperature: 90°F = (90 - 32) * 5/9 = 32.22°C
- Air-conditioned room temperature: 70°F = (70 - 32) * 5/9 = 21.11°C

3. Now we have the initial temperature (32.22°C) and the final temperature (21.11°C). Let's convert these temperatures to Kelvin by adding 273.15 to each value.
- Initial temperature: 32.22°C + 273.15 = 305.37 K
- Final temperature: 21.11°C + 273.15 = 294.26 K

4. Apply Charles's Law by using the ratio of the initial and final temperatures to calculate the new volume.
- V1 / T1 = V2 / T2
- 3 cu ft / 305.37 K = V2 / 294.26 K
- V2 = (3 cu ft * 294.26 K) / 305.37 K

5. Calculate the new volume:
- V2 = (882.78 cu ft K) / 305.37 K
- V2 ≈ 2.89 cu ft

Therefore, approximately one hour after being taken into the air-conditioned room at 70°F, the balloon will contain around 2.89 cubic feet of air.