Fri Sep 24 13:41:29 2021 GMT
residence Safety an initial What"s A "Water Rocket"?Water-Rocket Simulation typically Asked QuestionsContact united state
Q: just how do ns make and attach a parachute come the rocket?
A: A 10-20 inch diameter parachute made from a plastic garbage bag functions well for a 2-liter plastic bottle rocket weighing about 1/4 lb (4ounces).I"ll existing instructions for production the parachute below, but very first lets talk about some style decisions you should make.There space a few factors you may want to consider before designing your parachute:How much does mine rocket weigh?How rough is mine rocket?How high will certainly it fly?How quick is the wind?These determinants are necessary to your style because they result how fast you"ll desire the rocket to descend under parachute, and also how much down-range itwill go prior to returning come the ground.For many of united state there is restricted space because that our recovery area (the park, or her backyard).An example:Your rocket is going to walk 200 ft in the waiting (by simulator estimate), that weighs 3.8 onces, and also the wind is blowing at 6 miles per hour.If you have a 30 inch parachute on your rocket it will descend in ~ 2.3 feet per second.The wind is 8.8 feet per second.Your rocket will travel 765 feet down-range prior to landing.Do you have actually a field 800 feet wide?
If you reduce the size of the parachute to 8 inch it will descend in ~ 8.8 feet per second.Then the rocket will land 200 feet down-range indigenous apogee.So, how do i calculate the ideal size?
The actions of a circular parachute is governed by the drag it produces once pulled through the air.The resistance force as result of drag is:
Where:Ap = area of the parachuteCd = traction Coefficientρ = thickness of the wait (Rho)V = descent velocityUsing a little algebra we can rearrange this right into other forms:To calculation Velocity because that a given weight(R) and diameter:
or to calculation the area to provide a provided descent velocity for a offered weight(R):
Use this spreadsheet to calculate the suitable size for your parachute.
You are watching: Water bottle rockets parachute
Now develop the parachute:
You"ll need: A plastic garbage bag, the thin, dark, variety.Light-weight kite string."Scotch" or "Invisible" tape, 1/2" wide.3 feet of heavier nylon cable or cord.A thick rubber band.Step-by-step:
Cut two seams that the plastic garbage bag to open up it into a sheet.Cut a square that the plastic large enough on every side to encompass your parachute diameter.Fold the plastic square in half.Fold the plastic again to kind a 1/4 square.One corner of the square is the facility of her plastic sheet.All subsequent folds have to be at this corner, developing a wedge.Fold the plastic 3 an ext times, every time dividing the edge in half.This should kind a wedge of around 11-12 degrees.NOTE: shot and make these folds as sharp together you can.These folds will be visible later to overview the attachments of your shroud lines.Measure the parachute radius indigenous the allude of the wedge and also cut the folded plastic to form the circular outline of the parachute canopy.NOTE: girlfriend may likewise cut turn off 1-1.5 inch of the point to kind a 2-3 inch hole in the facility of the parachute canopy.A hole in the facility stabilizes a parachute so the it descends without wandering.Unfold the plastic top top a level surface (usually the kitchen table).
Attach 8 shroud lines as follows:Tie a node ~1 inch from the end of the kite string.Use 2 customs of invisible tape to affix the knotted finish of the string to the plastic in ~ 45 level intervals around the edge.Use the wrinkles lines, still clearly shows in the plastic, to guide placement the the string.Press the tape steady onto the plastic.Cut the shroud line length to complement 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 ~ above one finish of the heavier nylon cable or cord.Tighten this knot over the knotted finish of the shroud lines.The parachute is now completed. Test the parachute through a dummy load tied to the cord.Fold the parachute and throw it into the wait (outside!).
See more: Para Que Sirve El Aceite De Lavanda Usos Y Beneficios, Lavanda (Lavender)
Tie the rubber band in the middle of the cord to type a shock absorb using 2 loops about 8-10 inch apart.Attach the free end that the cord to her rocket with strapping tape, one of two people at the facility of gravity for more heavier rockets or the top ofthe rocket body under the nose cone.
for an ext information see:Paul Grosse: NSA - sleep Separates at ApogeeWikipedia: Drag(back)