Physics & Physical Science Demos, Labs, & Projects for High School Teachers

Inertia Example #517 – The Sledge Hammer & Anvil

Posted on: June 25, 2008


Do I really have 517 demonstrations of inertia? It feels that way, but of course I don’t. I max out at around 300. Anyway, this is similar to putting an anvil on your stomach and then hitting an anvil with a sledge hammer. I’m just not that trusting. Here’s how I made it safe for High School seniors:

I take a box of books. I have a case of Conceptual Physics books, they weigh about 80 lbs. I have a student come up to my demonstration table and lie down. I like to pick one of my more vocal (translate as annoying) but also smaller in frame kids. They lay on their back and I gently place the box of books on their chest and stomach. When they agree they are not in pain, I usually call up the biggest and strongest kid in the class. His job is to slam his fists down on the box of books as hard as he can. This is usually a friend of the one laying down, so the drama is even better.

As hard as he hits the box, the kid on the table barely feels anything. While he’s still there, I ask them about removing some of the books from the box and what do they think would happen. I like for them to take the thought experiment to the extreme, so I ask if we take all the books away and replace it with a single piece of paper. Then what would happen? My hope is that they see how the large mass has a lot of inertia and resists a change in motion.

This usually moves to about half the class trying this on each other at my table. Chaos, you bet, I encourage it. They are interested enough to get out of their chairs and try an experiment, you better believe I’m going to let them. I’ll take every teachable moment I can get.

About these ads

What do you think? Your opinion matters, leave a reply.

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

What’s New in 2013/2014?

Every year brings a change, this one is no exception.

I will be picking up the sophomore honors Algebra II class to keep them separate from the juniors. This should help accelerate them and put them on a stronger track towards Calculus. Looks like there will be only one section each of Physics and Calculus, but still two of Robotics & Engineering.

Hot topics this year are going to be the Common-Core Standards, Standards-Based Grading (SBG), improving AP Calculus scores, and somehow adding Python, maybe as a club.

Polls in the sidebar

Just a quick poll to help me understand who is stopping by my blog.

Yeah sure, lots from America, but look who else is here…

If you are badly in need of more email or for some reason jonesing for a physics fix, enter your email address so I can bother you with my newest rant on science.

Join 212 other followers

Blog Stats

  • 857,109 hits by nerds like me since June 1, 2008
June 2008
M T W T F S S
« May   Jul »
 1
2345678
9101112131415
16171819202122
23242526272829
30  
Follow

Get every new post delivered to your Inbox.

Join 212 other followers

%d bloggers like this: