Marshmallow Catapults, or Angry Marshmallows

As part of my unit on projectile motion, I will have my students build marshmallow catapults.  Students are more aware of the principles of projectile motion these days due to the popularity of the game Angry Birds.  By building their own catapult, they can bring the game to life.

A Google Image search of “marshmallow catapult” brings up lots of good ideas.  Some of my favs:

marsh1 marsh2 marsh3marsh4I plan on offering my students the choice of the following materials:

  1. Popsicle sticks
  2. Rubber bands
  3. Clothespins
  4. Plastic spoons
  5. Plastic bottle tops
  6. Tape
  7. Glue
  8. Cardboard
  9. Binder clips

Although any household or office supplies could be used.

Students will build their catapults, measure the distance and travel time, and then use kinematic equations to find the maximum height of trajectory.

Extensions of this activity could include challenging students to shoot the farthest, the most accurate, and to hit several targets.


Modeling Workshops for Summer 2013

A colleague I teach with strongly recommends the modeling approach to teaching science.  While I’ve read a little bit about it, I hope to attend one of the workshops being offered in the summer of 2013.

Here’s a summary of modeling instruction from the American Modeling Teachers Association for those who aren’t familiar with it:

Modeling instruction is one of the most successful reforms to the teaching of physics in the last 50 years. It is predicated on the notion that it is the nature of humans to think using “models”—conceptual representations of real things.  Firmly grounded in cognitive science and based upon the belief that science content cannot be separated from pedagogy, modeling instruction uses an iterative cycle of model construction, model testing and elaboration and model application to help students learn physics deeply and coherently. Even more important, it helps them learn to think like a scientist.



Newton’s Laws #5: Newton’s Laws at the Circus

PBS has an interesting site for their “CIRCUS” series featuring the physics of the circus.

For Newton’s laws, there is an activity guide and a video and explanation of forces.

The video features some adorable circus dogs performing tricks while explaining how Newton’s 3 laws are demonstrated with their movements.  The website also has some great diagrams that label the forces acting on the dogs.


Math-free Physics? Sign me up!

One of my favorite new physics sites has to be Pop Physics.

popphysicsHere’s my secret: I don’t really like math.  Math is a tool that helps me solve physics problems.  I’m more concerned with the bigger picture while others are busy with equations and variables.  This site encourages big picture thinking with real world examples.

Pop Physics is part blog with interesting news updates and links and part online textbook.  I like the news and links– they give real-world examples.  While the textbook will never replace math-filled types, it really makes you think about the concepts if you take the time to read it.

Inclined Plane Lab

Doing endless inclined plane problems on paper can get old really fast, so why not create a real-life version where students are responsible for taking measurements and using them to calculate actual information?

This lab doesn’t require a lot of fancy materials either.  All you need is some sort of ramp (like a 2 x 4), a cart or buggy, some meter sticks, and a spring scale.  Prop the ramp up on the chalkboard ledge, a chair, or a couple of books and you’re ready to go.  Students should be able to calculate Fg, Fnet F//, Fnormal, Ffriction,θ, μ, acceleration, and velocity.

Here’s the lab sheet I use: Inclined Plane Lab

Newton’s Laws #3: Newton’s Dark Secrets Video

I like to show my students the PBS video Newton’s Dark Secrets (free streaming from

dark secrets

Newton: crazy smart or just crazy?

Physics students hear his name often, but I like to give them some context of the type of man he was and the time in which he lived.  He is undoubtedly one of the great minds of science, but his personal life was rather strange and he was not a “people person.”  This video puts a name with a face and explains the development of his career.