system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do large buses not have seat belts included in them?

As a frequent rider of public transportation, I have become curious why, unlike most other vehicles on the road, why they don't require seat belts on them. I feel like they would be more dangerous without them but I honestly don't know.
gpt
Imagine hitting a basketball with a baseball bat. Now hit a bowling ball with the same force of the bat. You'll probably notice that the basketball will travel further.

Now, throw those two balls at the same speed at each other. You'll notice the bowling ball does not change much in terms of speed or direction after the impact.

The basketball in this case is a car while a bus is the bowling ball. A bus is usually 10 times as heavy as a car. If it gets hit by a car, it's so heavy so that it doesn't move much at all. Thus, the passengers won't move around the bus too much so seat belts are not as necessary.