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## 'Felix's Parachute Jump' printed from http://nrich.maths.org/

### Why do this problem?

This problem encourages students to consider the maths behind the world record breaking parachute jump by Felix Baumgartner on October 14th 2012. The context can lead to many engaging questions, a few of which are suggested in the problem.

### Possible approach

Begin by showing one of the video clips from Felix's jump - they are available on the

Red Bull Stratos website.

"What mathematical questions does the video prompt for you?"

Give students some time to discuss and share their ideas, and write up their questions on the board. If suggestions aren't forthcoming, the following are suggested in the problem:

- As Felix stepped from the capsule at 39km, what proportion of the Earth's surface could he see?
- Felix landed 9 minutes and 3 seconds after jumping. How much quicker would an object in freefall all the way down (ie without a parachute) land?
- Can you estimate the maximum speed Felix reached before opening his parachute after 4 minutes and 19 seconds of freefall?

*Of course, if you have a particular topic in mind, you could choose to share just one of these questions with the class and work on that.*
Once students have decided on a question to work on, they will need to do some modelling and research in order to answer their question. Here are some useful facts from the jump:

Height of jump: 39,045 m

Time spent in freefall: 4 minutes 22 seconds

Total jump time: 9 minutes 9 seconds

Radius of earth: 6378km

### Possible extension

Escape from Planet Earth
### Possible support

Cannon Balls