<![CDATA[Is it Better to Walk or Run in the Rain?]]> false false false false false false false true true false ]]> ./rainrunning/Screenshot 2020-03-18 at 4.18.27 PM (2).png ;; 20 1 false VARIABLE_EDITOR Var Table true false VARIABLE_EDITOR Var Table 2 true false VARIABLE_EDITOR Var Table 3 true false VARIABLE_EDITOR sizing true false CODE_EDITOR Init Page true false ODE_EDITOR Evol Page true false EVENT_EDITOR Event true false STATE_EVENT BISECTION 100 true t dt vxa -vyr -vyr RungeKutta 10000 0.00001 false false false false CODE_EDITOR FixRel Page true false =ha){ ht=ha; } } } if (ryn[i*nx+j]<(ha-dd)){ if (Math.abs(rxn[i*nx+j]-xa)=wa){ hs=wa; } } } } } totalrain=topsum+sidesum; for (var i=0;i0){ ad=0; adfont=ad*8; } if (xa>265 && pauseFlag==0){ alert("simulation has ended，press reset button to play again"); _pause(); // EJS.alert("simulation has ended，press reset button to play again",_pause); //pauseFlag=1; //}else if (xa>265 && pauseFlag==1){ //pauseFlag=-1; // _pause(); } ]]> HTML_VIEW_EDITOR HtmlView Page true false 0 0 0 800 600 true true Elements.Panel true Elements.Panel Elements.Label Elements.Slider Elements.ParsedField Elements.Label Elements.TwoStateButton Elements.Button true Elements.DrawingPanel Elements.Shape2D Elements.Segment2D false Elements.Group2D Elements.SegmentSet2D Elements.SegmentSet2D Elements.SegmentSet2D true Elements.Group2D Elements.Shape2D Elements.Image2D false Elements.Group2D Elements.Segment2D Elements.Segment2D Elements.Text2D Elements.Text2D false Elements.Group2D Elements.Arrow2D Elements.Text2D Elements.Polygon2D Elements.Polygon2D Elements.Arrow2D Elements.Text2D Elements.Panel Description

This program simulates the situation of a man running at different speeds V in the rain from ceiling m to ceiling n (fixed distance D = 24 meters). The simulation assumes that the volume of rain during the movement of the man is a fixed cuboid, the rain density is uniform and constant, the raindrops fall vertically on the ground (no wind), the rainfall speed is equal to speed u = 6 meters / second (terminal speed), and the man runs less than or equal to the rainfall speed (V less than or equal to u).

Whether one should run when it rains, and how much rain will land on you in the end is an interesting question. This simulation discusses the change in the amount of rain over the head, sideways and total rain (overhead + sideways) over time while running in the rain. What results do you find when the man is running at different speeds and the changes to the total value of these three quantities?

  1. How will the amount of rainfall landing on the head change when the man runs faster? (Increases / no change / decreases?) Why?
  2. How will the amount of rainfall landing on the side change when the man runs faster? (Increases / no change / decreases?) Why?
  3. How will the total amount of rainfall landing on the man change when the man runs faster? (Increases / no change / decreases?) Why?

Adjustable parameters

V: Running speed (m/s)

Simulation operation

After setting the adjustable parameters, press Play to execute the simulation, and press Reset to terminate the simulation.

Analog display

When the man is running, the light blue rectangle that increases from the top of the head represents the amount of rain that is dripping on the top of the head, and the blue rectangle that increases from the side represents the amount of rain that is coming from the side.

References

http://www.youtube.com/watch?v=3MqYE2UuN24

http://www.jstor.org/stable/pdf/3617483.pdf?refreqid=excelsior%3Acd01cc5b5ddbb2bc97fead6fe3cc3381

http://news.bbc.co.uk/1/hi/magazine/4562132.stm

http://snowball.millersville.edu/~adecaria/DERIVATIONS/Rain.pdf

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