# Parachute Sim with js v4.7

## Parachute Jump Simulator - by Rasheed Gadir, New Horizon High School.

Salam Ms. Shireen. This is a present from me to your G10 physics students. This model is very realistic and its predictions of jump duration, velocities and trajectories are very close to values obtained in real life. Parameters: You can use time-acceleration from 0.5 to 3.5 X. Air Resistance coefficient before deployment is kg/m . You can simulate free fall with no air resistance by setting . {click on New Sim to change parameters] The value of the resistance coefficient after deployment is adjustable. Typically, its value is 13.0 kg/m. for a 40 m2 canopy. Select mass of Jumper + parachute (mass of parachute kg. Select initial altitude AGL. Select speed of plane Select wind speed and direction. Tips: Use the graph view tool to drag and adjust the x and y axes. Check the [Show graph] checkbox to display the velocity - time graph, and trajectory of jump. The model: Both Quadratic & linear drag models where used ( The vertical motion is based on quadratic drag.. Parachute deployment takes a typical 4 s, during which drag increases linearly from to vertically, and horizontally. Mr. Rasheed

## Question 1: 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. To simulate free fall with no air resistance , click on [New Sim] then set ..
4. Compare and comment on your results from 2 & 3 above.
5. Compare and comment on the trajectory and velocity-time graphs of motions with and without air resistance.

## Question 2: 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, and trajectory of jump. Use the point tool and text tool to create and label the following points:

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 of air resistance when he was 50 m above the ground.