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START YOUR JOURNEY - LAWS OF MOTION

Newton’s Laws of Motion Challenge

 You Chose : 3. The Law of Action-Reaction: “For every action there is an equal and opposite reaction.”

You chose wisely!!

Newton’s Third Law of Action-Reaction is the essence of jet and rocket propulsion. Let’s look at a diagram of the combustion chamber of a rocket (essentially your bottle).

If it were closed, the pressurized air would push out on all sides equally, like a balloon.

However, open the nozzle and the escaping air leaves an unbalanced force on the opposite side of the bottle.

The “action” is the movement of air out of the nozzle. The “reaction” is the forward motion of the bottle.

Part of what determines the bottle’s velocity is the MOMENTUM (momentum = mass x velocity) of the escaping particles. There is another law, called the Conservation of Momentum Law, that requires the momentum of the bottle (bottle mass x bottle velocity) to be equal but opposite to the momentum of the escaping air (air mass x air velocity).

Before we continue, let's test what you know!

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