Physics Van 3-site Navigational Menu

Physics Van Navigational Menu

Q & A: Newton’s First Law of Motion

Learn more physics!

Most recent answer: 10/22/2007
I need an example of one of Newton’s Laws of Motion.
- london (age 11)
Newton's First Law of Motion says that an object will remain in its state of motion unless acted upon by a force. This means that a body not under the influence of ANY forces will either be traveling with a constant straight-line velocity relative to an observer or will be at rest (not moving) with respect to that observer. If a force acts upon the object, there will be a change in velocity (both speed and/or direction of movement), which is also known as acceleration. For example, the reason a car slows down after you take your foot off the gas pedal is because a force, specifically friction, is changing its speed. The reason the moon travels in a circular orbit around the earth is because a force, this time gravity, is continually changing the direction of its motion around the earth from a straight line to approximately circular. But in the absence of forces, an object will continue in its state of motion without changing.

(published on 10/22/2007)

Follow-up on this answer.