Newton’s Third Law
![Picture](/uploads/2/6/5/9/26590183/1367133.jpg?1400715265)
“For every action, there is an equal and opposite reaction”.
The size of the forces on the first object are equal to the forces on the second object.
Newton’s 3rd Law can be applied to rocket engines and launching.
When a rocket is launched there is a large force of expelled gases out of the back of the engine
and acts upon the earth while the force of the fuel combustion pushes back on the rocket to lift it into the air.
Engine Designation
The engine available to use for The Wizard is the Estes A8-3
A - stands for the impulse or the force exerted over time; as you move up in engines (From A to B to C… etc.) the impulse gets doubled. For the A engine the impulse is 2.5N.
8 - stands for the average force while the engine burns. The force needed for the maximum thrust for this engine is 10.7N which is 2.4lbs.
3 - stands for the time delay between the thrust and the ejection. For this engine the time is 3s.
8 - stands for the average force while the engine burns. The force needed for the maximum thrust for this engine is 10.7N which is 2.4lbs.
3 - stands for the time delay between the thrust and the ejection. For this engine the time is 3s.
Impulse Curve
- The grey area under the curve represents the Total Impulse of the engine while in flight. On this graph it is 8.83N/s.
- The highlighted curve represents the average Force of the engine during flight, in this case 2.60.
- The blue line from the end of the highlighted curve to the blue spike at 15s is the time delay until the ejection charge and the blue spike at 15s is the ejection occurring. In this diagram the delay is about 5.5000s
C6-7 Engine
- Total Impulse - 8.31N/s
- Average Force - 3.33
- Delay Time - 7.7000s
E9-6 Engine
- Total Impulse - 28.72N/s
- Average Force - 8.20
- Delay Time - 6.1000s
C6-5 Engine
- Total Impulse - 8.78N/s
- Average Force - 3.82
- Time Delay - 5.7000s
Wrong Engine/Failed Rocket Scenario
Caroline constructs an Estes Eggscalibur rocket (with the egg inside) and choses a D12-0 engine which is a booster stage engine.
The Estes website recommends: B6-2 (first flight), C6-3, C11-3, and D12-3 engines which are all single stage engines.
Since the D12-0 is meant for a two stage rocket and has no delay time the ejection charge will ignite while the rocket is still moving at full speed instead of slowing down during the delay time. The parachute will come out of the rocket, causing it to spiral downward and break the egg.
The Estes website recommends: B6-2 (first flight), C6-3, C11-3, and D12-3 engines which are all single stage engines.
Since the D12-0 is meant for a two stage rocket and has no delay time the ejection charge will ignite while the rocket is still moving at full speed instead of slowing down during the delay time. The parachute will come out of the rocket, causing it to spiral downward and break the egg.
Engines for The Wizard
The Estes website recommends engines: 1/2A6-2, A8-3 (First Flight), A8-5, B4-4, B6-4, B6-6, C6-5, and C6-7
Since I was flying The Wizard for the first time I selected an A8-3 engine so the rocket could fly to the higher altitude than with the 1/2A6-2 and still keep the rocket stable in the wind conditions of the day we launched.
Since I was flying The Wizard for the first time I selected an A8-3 engine so the rocket could fly to the higher altitude than with the 1/2A6-2 and still keep the rocket stable in the wind conditions of the day we launched.