Chapter 2, Problem 2RQ

According to Aristotle, what kind of motion requires no force?

To determine

The kind of motion that does not require force.

Answer to Problem 2RQ

The kind of motion that does not require force is natural motion.

Explanation of Solution

According to Aristotle, motions are classified as,

1. Natural motion

2. Unnatural motion

Aristotle believed that all bodies, that having motion without any force is known as the natural motion of that body. The movements of the sun, moon, and other massive bodies in the sky were considered in natural motion. These celestial bodies moved continuously without the need for any force. For example, it was natural for the object to fall towards the earth and smoke of a fire to rise in the air.

He believed that the motions that required some force like push and pull are unnatural. The movement of a block over a surface while applying some push or pull force is an example of unnatural motion.

Conclusion:

Therefore, the kind of motion that does not require force is natural motion.