The spring inside a clicky pen is a perfect way to learn about projectile motion. Post Views: 80 News PREVIOUS ARTICLE Apple’s iMac Pro arrives December 14, starting at $4,999 NEXT ARTICLE Facebook bats back after a second former exec accuses it of negatively impacting society Related Post Why I don’t care about net neutrality, or our country’s future / Dec 13 ‘The Martian’ and ‘Artemis’ author Andy Weir on Recode Media: transcript / Dec 10 This man has made more money trading cryptokitties than investing in his IRA / Dec 13 Leave a Reply Click here to cancel reply. Name (required) Mail (required) (not be published) Website