Ariadna, Biel, Ludovica, Agnese, Filippo, Davide

Have a look to this paper (it is in Italian but Italian students can translate it to their Spanish mates) and solve the problem: 

https://drive.google.com/open?id=0B0rVayd5faSPbzBYcktEVHNUU1k

If you have time, you can try also to change the conditions, for instance asking the walking person to accelerate constantly in his/her path. 

When you have collected enough data and you have answered to all the questions, prepare a presentation explaining to your mates what you obtained and how you got them. 

Discuss with the other group having to solve the same task and compare the results.