|What's the buoyant force on a lionfish? I ain't doing this|
demo, but you can see the demonstrations I do do at this link.
30 November 2011
27 November 2011
17 November 2011
15 November 2011
|Woodberry Forest 21, EHS 12 in 2011. But this picture|
is from 2010.
11 November 2011
(1) How do you help your students review for a major cumulative exam?
(2) Why does your email say "Nacho Man?"
The point is, extra credit and food provide significant incentive to bring students into the classroom during what otherwise would be wasted independent study time. Once students are in the classroom working diligently on physics questions, learning is happening even if music, conversation, and nachos are happening simultaneously.
Check out this post.
Peter Chen, a student who is well-versed in video production, intends to create a "cooking show" style clip about Nacho Day in our physics department. I'll post the link in a month or so.
08 November 2011
1. A possible force vs. time curve for a ball struck by a bat is shown in the figure.
(a) Calculate the impulse delivered to the ball.
(b) This 0.25 kg ball was initially moving toward the bat at a speed of 20 m/s. Calculate the exit speed of the ball.
Understandable mistake, combo platter: The student who used the max force rather than the average force to calculate impulse, AND who didn't account for the ball's changing direction, got something like 68 m/s. Well, that's about 150 mph, and still not horrid -- after all, that's only 40% above the typical 100-120 mph exit speeds in the majors. (I'm recalling my Physics of Baseball by Robert Adair; I hope I have that value right. Please correct me in the comments if I'm wrong.) That answer loses only the two points for the direction change issue.
05 November 2011
|Happy and Sad Balls -- which one produces|
more force when dropped onto a force plate?