Engineering Question #2661

Harshita, a 15 year old female from Sydney asks on March 18, 2005,

I have conducted an experiment with a parachute. I was investigating whether the time taken to reach the ground for a parachute was altered by the size of the hole in the centre of the canopy. The parachute with the larger hole took more time to reach the ground compared to the parachute with the smaller hole. Why did this occur?

viewed 20305 times

The answer

Betty Pfeiffer, sky diving expert, High Energy Sports, Anaheim, CA answered on March 21, 2005

The answer requires an additional question. Was the parachute with the smaller hole oscillating? If the hole is too small the air flowing into the parachute will have to escape somewhere else. The lighter the weight the more it will want to release air from the skirt causing the parachute to oscillate (wobble back and forth spilling air out the edges) and momentarily accelerate towards the ground. The larger hole will stabilize the system so it is less prone to oscillation. This results in a more constant rate of descent. Of course if the large hole is too large the parachute will descend much too fast.

Add to or comment on this answer using the form below.

Note: All submissions are moderated prior to posting.

If you found this answer useful, please consider making a small donation to