Action - Reaction
Can you parallel park in space? Yes, but it’s tricky! While friction and air resistance make maneuvering and stopping on Earth easy, in space there are some challenges. But scientist Isaac Newton helped show us the way.
Concepts Include |
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| Force | Acceleration | Inertia | |||
| Velocity | Mass & Weight | Thrust | |||
Launching a Rocket - Newton's Third Law
For every action, there is an equal and opposite reaction.
| Action | |
| The spent fuel escapes the rocket through a hole called the nozzle. |
| Reaction | |
| The rocket moves away from the spent fuel, in effect pushing against it. |
| The more spent fuel the rocket leaves behind, and the faster the spent fuel moves, the faster the rocket will fly. | |
| The rocket doesn’t push against the launch pad, the air or anything else except its own fuel. This is the reason why rockets work in outer space. |
Stopping a Rocket |
|
| A rocket moves when its engine fires in the opposite direction. | |
| Even after the engine shuts off, the rocket keeps moving in the same direction. | |
| To stop, the rocket turns around and fires its engine in the direction of motion. | |
| The tendency of a rocket (or anything else) to keep moving is inertia. |
Resource Links |
|
| The Physics Classroom | |
| Newton’s Three Laws of Motion |
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