Wed Sep 22 14:04:04 2021 GMT
home Safety very first What"s A "Water Rocket"?Water-Rocket Simulation generally Asked QuestionsContact united state
Q: how do ns make and also attach a parachute to the rocket?
A: A 10-20 customs diameter parachute do from a plastic rubbish bag functions well for a 2-liter plastic party rocket weighing around 1/4 pound (4ounces).I"ll present instructions for production the parachute below, but very first lets talk about some design decisions you should make.There space a few factors you might want to consider prior to designing her parachute:How lot does my rocket weigh?How rugged is my rocket?How high will certainly it fly?How rapid is the wind?These components are crucial to your design because they effect how rapid you"ll desire the rocket come descend under parachute, and how much down-range itwill go prior to returning to the ground.For most of us there is limited space for our restore area (the park, or her backyard).An example:Your rocket is walking to go 200 ft in the waiting (by simulator estimate), the weighs 3.8 onces, and the wind is blowing in ~ 6 miles per hour.If you have actually a 30 inch parachute on her rocket it will certainly descend in ~ 2.3 feet per second.The wind is 8.8 feet per second.Your rocket will travel 765 feet down-range before landing.Do you have actually a ar 800 feet wide?
If you mitigate the dimension of the parachute come 8 inches it will descend at 8.8 feet every second.Then the rocket will land 200 feet down-range from apogee.So, how do i calculate the best size?
The actions of a one parachute is administrate by the traction it produces when pulled v the air.The resistance force as result of drag is:
Where:Ap = area that the parachuteCd = drag Coefficientρ = density of the air (Rho)V = lower velocityUsing a little algebra we deserve to rearrange this into other forms:To calculate Velocity because that a given weight(R) and also diameter:
or to calculation the area to carry out a provided descent velocity for a given weight(R):
Use this spreadsheet to calculation the ideal size for her parachute.
You are watching: Water bottle rockets parachute
Now build the parachute:
You"ll need: A plastic garbage bag, the thin, dark, variety.Light-weight dragon string."Scotch" or "Invisible" tape, 1/2" wide.3 feet of heavier nylon wire or cord.A thick rubber band.Step-by-step:
Cut two seams that the plastic rubbish bag to open it into a sheet.Cut a square that the plastic huge enough on each side to include your parachute diameter.Fold the plastic square in half.Fold the plastic again to form a 1/4 square.One edge of the square is the facility of her plastic sheet.All subsequent folds need to be in ~ this corner, developing a wedge.Fold the plastic 3 an ext times, each time dividing the edge in half.This should type a wedge of about 11-12 degrees.NOTE: shot and make these folds together sharp as you can.These folds will be visible later to overview the attachments of your shroud lines.Measure the parachute radius indigenous the point of the wedge and also cut the urgent plastic to kind the circular rundown of the parachute canopy.NOTE: girlfriend may additionally cut turn off 1-1.5 inches of the point to type a 2-3 customs hole in the center of the parachute canopy.A feet in the center stabilizes a parachute so that it descends there is no wandering.Unfold the plastic onto a level surface (usually the kitchen table).
Attach 8 shroud lines together follows:Tie a knot ~1 customs from the end of the dragon string.Use 2 inches of invisible ice to connect the knotted end of the string to the plastic in ~ 45 degree intervals approximately the edge.Use the wrinkles lines, still clearly shows in the plastic, to overview placement of the string.Press the tape firmly onto the plastic.Cut the shroud line size to enhance the diameter that the canopy.
Gather together the ends of every 8 shroud lines.Tie one over-hand knot about 3/4 customs from the end.Tie a slip-knot top top one end of the more heavier nylon cable or cord.Tighten this knot over the knotted end of the shroud lines.The parachute is currently completed. Check the parachute v a dummy weight tied come the cord.Fold the parachute and throw it right into the air (outside!).
See more: Star Wars Secrets Of The Empire Review, Void Vr Review: Star Wars Secrets Of The Empire
Tie the rubber band in the center of the cord to form a shock absorber using two loops around 8-10 customs apart.Attach the cost-free end that the cord to your rocket with strapping tape, one of two people at the facility of gravity for heavier rockets or the peak ofthe rocket body under the sleep cone.
for more information see:Paul Grosse: NSA - nose Separates at ApogeeWikipedia: Drag(back)