When a refrigerator is full of food, it can feel easier to lift due to a principle in physics known as the "lever principle" or "mechanical advantage." This principle states that using a lever, such as a fridge with a door as a lever arm, can amplify the force applied to lift an object.
Here's how it works:
Center of Mass: When the refrigerator is empty, its center of mass is closer to the middle of the fridge, making it more balanced. This means that when you try to lift it, the weight is distributed more evenly, and you have to apply force to lift the entire weight at once.
Full Fridge - Shifting Center of Mass: When you fill the fridge with food, the weight is distributed differently. The food items are usually concentrated near the top and door of the fridge, away from the bottom. This shifts the center of mass higher up in the fridge, closer to the door.
Increased Mechanical Advantage: With the center of mass closer to the door, you have more leverage when you lift the fridge from the bottom. This increased lever arm results in a mechanical advantage, making it feel easier to lift because you are using the weight distribution to your advantage.
Frictional Force: Additionally, when the fridge is full, it tends to create more friction with the floor due to the increased weight pressing down. The friction helps prevent the fridge from slipping, making it feel more stable and easier to lift.
It's important to note that while the leverage effect may make it feel easier to lift a full fridge, you should still be cautious when attempting to move or lift heavy objects to avoid injury. Always practice proper lifting techniques, and if possible, get help from others when moving large appliances to reduce the risk of strain or injury.