Worth mentioning here is the one about Relative velocity.
http://fnoschese.wordpress.com/2014/09/24/day-16-relative-motion/
He showed students video of ball being thrown with a certain speed and direction from a truck moving with exactly same speed and in exactly opposite direction. If you know vector addition, you can easily guess that this would result in the velocity of the ball equal to 'zero'. In real life it is rather hard for anyone to see such actions in motion.. but thanks to technology and people like Frank who take time to explain this further. In the video it is really cool to see the ball actually having no velocity at all and standing still before it starts to fall vertically down because of gravity. His experiments with the buggy not moving from its original position is very interesting too (below). This experiment can easily be replicated in any classroom.
Taking this a step further, Frank's slides contain various cases of relative velocity in action, that students can actually vote on. A similar lesson is on my agenda when I teach during winter. I would love to use Socrative for students to vote on.
I have commented on this blog post and also subscribed to his blog site. It is amazing to see so much out there, for us Physics teachers to get excited about.
