Section 8 EO C340.06 – LAUNCH A WATER ROCKET

Resources needed for the delivery of this lesson are listed in the lesson specification located in A-CR-CCP-803/PG-001, Chapter 4. Specific uses for said resources are identified throughout the instructional guide within the TP for which they are required.

Review the lesson content and become familiar with the material prior to delivering the lesson.

Construct a launching pad as shown at Annex W.

Prepare a string guidance system as shown at Annex X.

Photocopy Annex Y for each cadet.

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A practical activity was chosen for TPs 1 and 2 as it is an interactive way to introduce cadets to water rockets. This activity contributes to the understanding of rocketry in a fun and challenging setting.

A group discussion was chosen for TP 3 as it allows the cadets to interact with their peers and share their knowledge, experiences, opinions, and feelings about water rockets.

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By the end of this lesson the cadet, as a member of a group, shall have constructed and launched a water rocket.

It is important for cadets to launch a water rocket so that they can experience the difference that a higher exhaust pressure makes in rocket flight, compared with using an effervescing tablet for power as was done in EO M140.01 (Build and Launch a Model Rocket, A-CR-CCP-801/PF-001, Chapter 13, Section 1).

The object of this activity is to have the cadets construct a water rocket, which will fly under its own self-contained power.

Cadets shall be organized in groups of no more than four, working together at one table, with all the resources required to build a water rocket.

1.Give each cadet a copy of Annex Y.

2.Explain the instructions located at Annex Y.

3.Each group will construct a water rocket in the manner depicted in Figure 15Y-1.

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The cadets’ participation in the activity will serve as the confirmation of this TP.

The objective of this activity is to have each group of cadets launch a water rocket constructed in TP 1 and experimentally determine its flight characteristics.

1.The CO shall select an outdoor area with controlled access for this training, at least 10 m by 20 m.

2.The string guidance system shall be secured to a suitable tower and the launch pad.

3.Place the launch pad in the centre of the launch area.

4.Anchor the launch pad securely in place.

1.Have one group of cadets place their water rocket, quarter filled with water, on the launch pad.

2.Ensure other cadets stand back 5 m; if necessary, rope off the launch site.

3.After the water rocket is attached to the launcher, have one cadet pump air into the rocket to more than 344 kPa (50 psi) pressure.

4.When pressurization is complete, all cadets shall stand behind the launch control officer.

5.Before conducting the countdown, ensure that the guidance system area is clear.

6.Have one cadet launch the water rocket by pulling the launch release cord.

7.Repeat this process for each group.

8.When all water rockets have been launched, have the cadets retrieve their water rockets.

The cadets’ participation in launching a water rocket will serve as the confirmation of this TP.

Characteristics of the Successful Launches

The forces acting upon the cadets’ water rockets in flight are those acting upon any aircraft:

Drag and lift are atmospheric forces that result from air coming in contact with the body of the water rocket.

There are many propellants used in rocketry, resulting in a variety of exhaust pressures and velocities. The greater the exhaust pressure, the higher the exhaust velocity. The rocket’s power is increased as exhaust velocity of the propellant increases.

When launching a water rocket, there is a difference that a higher exhaust pressure makes in rocket flight, compared with using an effervescing tablet for power as was done in EO M140.01 (Build and Launch a Model Rocket, A-CR-CCP-801/PF-001, Chapter 13, Section 1). Since the water rocket launched in this lesson is heavier when filled with propellant, it may start slower, but the greater mass of the propellant may allow it to attain even greater speeds and distances.

Rocket Behaviour Under Newton’s Laws

First Law. Every object in motion tends to remain in motion until an external force is applied to it.

Second Law. The direction of acceleration is the same as the direction of the force. Therefore, since the reactive force pushes upwards against the bottle as the water is directed downwards, the force acting upon the water rocket is also directed upwards.

Third Law. For every action there is an equal and opposite reaction. Therefore, matter such as water particles escaping outward from the rear nozzle will push upon the body of the water rocket.

The cadets’ participation in the group discussion will serve as the confirmation of this TP.

The cadets’ participation in launching the water rocket and in the group discussion will serve as the confirmation of this lesson.

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There are many propellants used in rocketry, resulting in a variety of exhaust pressures and velocities. The greater the exhaust pressure, the higher the exhaust velocity. The rocket’s power is increased as exhaust velocity of the propellant increases.

Prior to this lesson, instructors shall prepare a launching platform and guidance system as shown at Annexes W and X or reference C3-016.

The launching pad should be saved for future training.

Each group shall be allowed a number of attempts to achieve a successful launch.

If a suitable location for this launching water rockets is not available at the squadron’s LHQ, that part of the lesson can be carried out as part of a field exercise.