[size=150]Salam Ms. Shireen.[br]This is a present from me to Year10 physics students at New Horizon School.[br][br]This model is very realistic and predicts jumps duration in close agreement with real life.[br][br][b]Parameters:[/b][br]Students can use time acceleration from 0.25 to 4 X to speed up or slow down the sim.[br]Air Resistance coefficient before deployment is 0.29 kg/m [/size][br][size=150]After deployment, coefficient is adjustable. Typical value is 13.0 kg/m. [br]Students can also:[br][list][*]Select the mass of Jumper + parachute .[/*][*]Select the initial altitude AGL[/*][*]Select the speed of the plane.[/*][*]Select the wind speed and wind direction.[br][br]Tip: Use the graph view tool [icon]/images/ggb/toolbar/mode_translateview.png[/icon] to drag and adjust the x and y axes.[/*][/list][/size][br][b]The model:[/b][br][br]Both Quadratic & linear drag models where used ( The vertical motion is based on quadratic drag..[br]Chute deployment takes a typical 3 s period, during which the drag increases linearly from c1 to c2..[br]Horizontal drag coefficient is the same c1 until parachute deployment.[br][br]Mr. Rasheed
1- Click on [b][New Sim][/b] and select an initial altitude( Height above ground level) and mass (Typical mass of a parachute is 14 kg), then click [b][Finish].[/b][br][br]2- Start the simulation and allow the jumper to fall freely [b]WITHOUT [/b]deploying the parachute. Note the [b]vertical velocity[/b] of the jumper when he hits the ground.[br][br]3- Calculate the vertical velocity of the jumper, and total time of the jump if there was no air resistance.[br][br]4- Compare and comment on your results from 2 & 3 above.[br][br]
Give a practical reason why the parachute [b]should not[/b] be deployed [b]immediately [/b]after jumping off the plane.
Reset the simulation, and start a new jump.[br]This time, deploy the parachute at a safe altitude. (If you deploy the chute at high altitude, the jump will take longer to complete). [br]Check the [Show graph] checkbox [icon]/images/ggb/toolbar/mode_keepinput.png[/icon] to display the [b]velocity - time graph, [br][/b]Use the [b]point tool[/b] [icon]/images/ggb/toolbar/mode_pointonobject.png[/icon] and [b]text tool [/b][icon]/images/ggb/toolbar/mode_text.png[/icon] to create and label the following points:[br][b][color=#ff0000](IMPORTANT : DO NOT RESET THE SIMULATION AFTER ANSWERING Q1 TO Q5 BELOW)[/color][/b][br][list=1][*]A point labelled [b][size=150]U[/size][/b], where the jumper was moving with uniform acceleration. Give an [b]estimate [/b]of the value of this acceleration.[br][br][/*][*]A point labelled [b][size=100][size=150]T[/size][/size][/b], when jumper was falling with terminal velocity.[br][br][/*][*]A point labelled [b][size=150]D[/size][/b], where the acceleration was decreasing.[br][br][/*][*]a point labelled [b][size=150]M[/size][/b], when jumper was decelerating at rate close to the maximum deceleration.[br][/*][/list]
[*][size=150]Explain why the acceleration at [b]D[/b] was decreasing.[/size][br][br][/*][*][br][/*][*][/*]
[size=150]On a different high altitude jump, another jumper with a total mass of 90 kg, jumped from 5,000 m. He deployed his parachute at 800 m. Calculate the magnitude of air resistance when he was 50 m above the ground.[/size][color=#333333] [/color]