# My Parachute Sim Js v 5.3

A good realistic model,

## Parachute Jump Simulator

Salam Ms. Shireen. This is a present from me to Year10 physics students at New Horizon School. This model is very realistic and predicts jumps duration in close agreement with real life. Parameters: Students can use time acceleration from 0.25 to 4 X to speed up or slow down the sim. Air Resistance coefficient before deployment is 0.29 kg/m ﻿After deployment, coefficient is adjustable. Typical value is 13.0 kg/m. Students can also:
• Select the mass of Jumper + parachute .
• Select the initial altitude AGL
• Select the speed of the plane.
• Select the wind speed and wind direction. Tip: Use the graph view tool to drag and adjust the x and y axes.
The model: Both Quadratic & linear drag models where used ( The vertical motion is based on quadratic drag.. Chute deployment takes a typical 3 s period, during which the drag increases linearly from c1 to c2.. Horizontal drag coefficient is the same c1 until parachute deployment. Mr. Rasheed

## Q1: The effect of Air Resistance:

1- Click on [New Sim] and select an initial altitude( Height above ground level) and mass (Typical mass of a parachute is 14 kg), then click [Finish]. 2- Start the simulation and allow the jumper to fall freely WITHOUT deploying the parachute. Note the vertical velocity of the jumper when he hits the ground. 3- Calculate the vertical velocity of the jumper, and total time of the jump if there was no air resistance. 4- Compare and comment on your results from 2 & 3 above.

## Q2: Parachute Deployment:

Give a practical reason why the parachute should not be deployed immediately after jumping off the plane.

## Question 3: The Graph

Reset the simulation, and start a new jump. This time, deploy the parachute at a safe altitude. (If you deploy the chute at high altitude, the jump will take longer to complete). Check the [Show graph] checkbox to display the velocity - time graph, Use the point tool and text tool to create and label the following points: (IMPORTANT : DO NOT RESET THE SIMULATION AFTER ANSWERING Q1 TO Q5 BELOW)

1. A point labeled U, where the jumper was moving with uniform acceleration. Give an estimate of the value of this acceleration.
2. A point labeled T, when jumper was falling with terminal velocity.
3. A point labeled D, where the acceleration was decreasing.
4. a point labeled M, when jumper was decelerating at rate close to the maximum deceleration.
5. Explain why the acceleration at D was decreasing.
6. 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.