Foods cook faster when placed in a pressure cooker. This is because the pressure on the surface of the water is the atmospheric pressure, and the boiling point of water is normal.

Foods cook faster in a pressure cooker due to the increased pressure inside the cooker. Here's a step-by-step explanation:

1. When the pressure cooker is sealed and heat is applied, the water inside starts to boil and turns into steam.

2. Since the steam cannot escape, it causes the pressure inside the cooker to increase.

3. The increased pressure directly impacts the boiling point of water. Under normal atmospheric pressure, water boils at 100 degrees Celsius. However, under higher pressure, the boiling point of water increases.

4. This means that the water and therefore the steam inside the pressure cooker can reach temperatures higher than 100 degrees Celsius.

5. The high pressure steam has two effects. It both penetrates the food to cook it more quickly, and at the higher temperature, chemical reactions that cook the food happen more quickly.

6. Therefore, the increased pressure inside the pressure cooker allows food to cook faster than it would under normal atmospheric conditions.