# Newton's third law of motion

### Newton's third law of motion

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##### Meghan Brown
Meghan's Personal Gallery
##### Transcript
00:04
Action & Reactions
00:06
Newton's 3rd law of motion
00:09
Why did Newton establish those 3 laws of motion?
00:10
- He developed his three laws in order to explain why the orbits of the planets are ellipses rather than circles, at which he succeeded, but it turned out that he explained
00:16
What are the laws of motion ?
00:16
well to begin, there are 3 laws of motion. They all focus on the motion of an object and forces and forces acting on it.
00:18
Today, we're just going  to focus on the third law.  Which talks about ... Could you guess ?
00:23
Newton's third law states that when two bodies interact, they apply forces to one another that are equal in magnitude and opposite in direction.
00:23
Actions and Reactions!!!
00:23
In a rocket engine, hot exhaust gas is produced through the combustion of a fuel with an oxidizer. The hot gas flows through the rocket nozzle and is accelerated to the rear of the rocket, In re-action, a thrusting force is produced on the engine mount. The thrust accelerates the rocket as described by Newton's 2nd law,but we're not gonna get into that.
00:28
For every action, there is an equal but opposite reaction.
00:31
Motion is mathematically described in terms of displacement, velocity, acceleration, speed, and time.
00:33
Newton's third law is useful for which forces are external to a system.
00:36
00:36
Thank You