Water Rockets An Investigational Experiment free essay sample

This report will investigate, design, perform and analyse an experiment on water rockets and explain how a water rocket reaches a maximum height using the concept of physics and experimental results. Hypothesis If the water level in the water rocket is increased, then the chances of obtaining the maximum height will also increase. This is because more thrust (force) is needed to make an object accelerate, and the greater the mass of an object, the greater the thrust it provides. Theory Statement The group will analyse and determine the amount of water needed to obtain the maximum height of the water rocket. Rocket motors generate a push or â€Å"thrust† by expelling a propellant out of the nozzle. The action is the movement of water out of the nozzle while the reaction is the forward motion of the rocket. The greater the â€Å"thrust†, the faster the rocket will accelerate. The other force that is acting on the rocket is the gravity; as the rocket goes up with the help of the thrust, the gravity pulls it down and brings the rocket back down to the ground. The group will use water because it is heavier and denser than air. More water molecules are packed into a given volume. Risk Assessment . Select a grassy field at least 30m wide. 2. Place the launcher in the centre of the field. 3. Observers should stand back several metres (approximately 10m). 4. The member responsible for pumping air in the rocket should wear eye protection. 5. The bottle rocket should be pumped at the maximum of 40 pressures per square inch (psi) and never above 40psi. 6. When pressurization is complete, everyone should stand back for about 10m for countdown. Two-litre bottles can weaken and explode. 7. Continue countdown and launch the rocket only when recovery range is clear. 8. If you do not experience lift off, call your teacher. (Remember that the rocket is pressurized and may blast off when you touch it. ) 9. Never stand over the rocket. Materials 2 empty 1. 5-litre soda bottle1 cardboard 1 launch pad 1 ruler 1 bicycle pump1 clinometer 1 rolls of duct tape1 beaker (600ml) A pair of scissorsa pair of safety glasses 1 bucket of water Setup Scenario Model Procedure Constructing the Model 1. An empty 1. 5litre soft drink bottle was cut in to half using a pair of scissors. 2. A nose cone was formed using the top of the halved bottle. 3. A nose cone was attached at the bottom f the other bottle. 4. Three cardboards were cut into a trapezium shape, after that the cardboard was wrapped with duct tape and was attached at the top of the other bottle to form a fin. Experiment: Launching the Water Rocket 1. A launch pad was set in the middle of a grassy field. 2. A water was filled in the water rocket (200ml, 400ml, 600ml) 3. A water bottle filled with water was car efully placed on the launch pad. 4. A bicycle pump was used to pump air inside the water bottle. (40psi) 5. A member of the group took hold of the rope which was attached to the launch pad and moved 10metres away. 6. Another member stood 30m away from the launch site to record the angle of the water rocket using a clinometer. 7. A member counted down till the launch was completed. 8. A member retrieved the water rocket. 9. The results were collated by a member. 10. The experiment was repeated twice on each of three different measurements of water. Controlled Variables * Amount of psi used in the water rocket * Shape of the fin/number of fins * Shape of the nose cone Data/Results Above eye level: Water Level (ml)| Trial 1| Trial 2| Average| | Angle( °)| Height(m)| Angle( °)| Height(m)| Angle( °)| Height(m)| 200ml| 20 °| 10. m| 30 °| 45m| 25 °| 28m| 400ml| 50 °| 35. 8m| 60 °| 52m| 55 °| 43. 9m| 600ml| 63 °| 58. 9m| 60 °| 52m| 61. 5 °| 55. 5m| Data Analysis Water Level (ml)| Average Height + Abi’s height| 200ml| 28. 7m | 400ml| 44. 6m| 600ml| 56. 2m| Discussion The water levels used were, 200 mL, 400mL and 600mL and two experiments were conducted with each water level. The maximum height obtained was 56. 2m with a water level of 600ml based on the results collected from the six experiments. With each water level, as the water level increased, the height of the rocket also increased with the help of the nose cone and fins attached to the rocket. Some modifications were used to improve the flight of the rocket. For example, fins were used in this experiment because they provide aerodynamic force stability for the bottle rocket; a nose cone was also added to reduce wind resistance which can prevent the water rocket from reaching its highest point. The maximum level of water (600ml) obtained the maximum height, because a bottle that is heavier has more Inertia, because it has more mass. More Inertia offers greater resistance to change in direction; which means that the wind will have less effect on a bottle with more Inertia. The data collected was reliable because of the repetition of the launch experiment with each water level. Possible errors could include: the clinometer – as the person who was taking the angle he/she cannot automatically detect the highest point because the rocket was moving; the way we put the bottle on the launch pad – as we put the bottle in the nozzle, it leaks which makes the water level decrease, which makes the experiment biased; the launcher – it was not stable, which can affect the progress of the rocket to get to its highest point; the fins – they were made of cardboard. The more they got wet, the heavier the bottle rocket is, which makes the weight of the rocket different in every experiment; the weather – it was a bit windy which made the flight a little difficult; and lastly, the repetitions of trials – the trials should have been done more than twice to increase accuracy. To improve this experiment, the group should have done the experiment on a less windy day; the group should have done a trial and error before doing the actual experiment to adjust some modifications. The group should also have used other various water levels to make the comparison more accurate. Conclusion In conclusion, this report has investigated, designed, performed and explained an investigational experiment of water rockets through the concept of physics and experimental results. The group conducted two experiments each; three different water levels and determined the maximum water level needed to obtain the highest maximum height. It was hypothesized that if the water level in the water rocket is increased, then the chances of obtaining the maximum height will increase. This is because the greater the mass of an object, more thrust (force) is needed to make the object accelerate. Based on the evidence and gathered results, the hypothesis was correct. This is because the more water that was put in the rocket the more force it provided for it to make it fly. The modifications, such as the fins and nose cone also helped the rocket to reach its highest point.