https://www.dropbox.com/scl/fi/dpz547nydih416n4wye7o/2020.pptx?rlkey=et9r2f30xc9ubpt2qpeyg4ijz&e=1&dl=0

https://www.dropbox.com/scl/fi/79m4zhxe9awphipaavs56/2021.pptx?rlkey=vlnpmrqdzr5vj2lj5ccdiczbd&e=1&dl=0

https://www.youtube.com/watch?v=xQ4znShlK5A

προσομοίωση:    https://www.seilias.gr/images/stories/html5/freeFall.html