More Newton Footage

Our school got ahold of some MacBook Airs, so I decided to flex my film editing skills with this one.  We reviewed Newton's laws through a series of activities and I recorded them with my high speed camera.  Here's the result.

Thor vs. Physics!

To help demonstrate Newton's 3rd Law of Motion, I have a student stand on a rotating platform and swing my homemade Mjolnir (http://rjcosplay.blogspot.com/2012/05/my-mjolnir.html).  I had "Loki" stand in front of him and I assured her that she could not be hit with the mighty hammer.  Sure enough, every swing of the hammer moved "Thor" in a circle in the opposite direction of the hammer and he never landed a blow.

We also demonstrated the 3rd Law by using balloons.  A couple students aimed them at their foreheads and let go.  The air rushing out of the balloons forced the ballons into their faces. 

As a bonus, we did a demonstration on the conservation of momentum.  A ping pong ball dropped on a golf ball is launched super high due to the larger mass of the golf ball.

Fight Science!

Way back in college, I recall seeing a special on National Geographic called Fight Science.  At the time, I was studying Isshinryu Karate and was pretty interested in combining the study of martial arts with Scientific theories and measurements.  While the "measurements" were presented in a manner that promoted the show rather than the Science, it was still an interesting show with some good explanations of fundamental concepts of Physics.

In class today, we're talking about force.  I have my students make a hypothesis about which fighter will be able to punch the hardest based on what they know about force.  The fighters hit a crash test dummy, and we get results in pounds (I convert to Newtons).

This usually leads to pretty thoughtful discussions about how the size/mass of the fighter affects the force of the punch and how each fighter can generate speed in a punch. 

It's an interesting lesson that grabs the attention of a lot of the students whose interests lie in the somewhat unsavory realm.  I think its actually a good idea to promote this kind of training for students who get in trouble a lot.  Any martial art teaches discipline and structure, which most kids need.  Also, they're a lot of fun.

Newtoooooooon!

I started teaching Newton's Law of Motion today.  I presented my students with some inertia based challenges.  Each of these was a take on the old tablecloth trick.  They had to remove a piece of paper from between two bottles, or from under a coin with one finger.  Below are some of the results at 300 fps.

High Speed Highlight

A couple years ago, I got ahold of a camera that shoots high frame rate video.  The result is a super slow motion video that I can use in class to demonstrate many wonderful Science concepts and I can use these videos to make somewhat accurate measurements of actions too fast to normally see.

In class today, we were measuring the velocity of a student punching.  That backdrop is set up in increments of 0.1 m.  Anyone with a stopwatch can record the time and the rest of the students can calculate the velocity of the punch.  I had several students do this and compete for the title of fastest hands.

We also redorded Sackboy riding a skateboard.  We estimated that the distance between the "rock on" hands was about 1 m.  We recorded the velocity at the start of the hill, the bottom of the hill, and the time it took to get to the bottom.  With this information, the students could calculate his acceleration.

Finally, I ended class with a demonstration related to Newton's cannonball experiment.  The cart moves and fires the ball straight up.  Due to the motion of the cart, the ball lands back in the lancher.

Photogates!

 

A few years ago, I got ahold of some photogates to use in class.  They've got a beam between two points on a gate that start a timer when broken.  Not only does it allow for very accurate measurements, it measures to the ten-thousandths of a second.

 

In class today, we're measuring the acceleration of a golf ball down a ramp (thrilling stuff).  I built a wonderful little velocity device out of a hot wheels car and sent it down the ramp.  By measuring the length of the card and the times from the photgates, I can calculate the initial/final velocity, the time between the two, and the acceleration.

Mario Kart? Science!?

While teaching my students about motion, I have to distinguish between velocity and acceleration.  Most students have an idea that acceleration means to speed up.  They've ridden in cars and can feel themselves getting pushed into a seat when a car takes off from a stop.  But it's not something they're used to quantifying.  Fortunately, I have a tool in the back pocket to help...MARIO KART!

I put my DS under the Elmo camera and project it on my big screen.  Then I compare Toad and Bowser.

Toad:  High acceleration/low speed.

Bowser:  Low acceleration/high speed.

Then I do a race with each character without using any power ups and have my students record any observations about how the character performs.  Here are some of their observations:

Toad:  Has good starts; makes it around turns easily; has trouble catching up to people.

Bowser:  Has crummy starts, crummy turns; has little trouble catching up to people.

Poor Bowser can't get off the line.

Because acceleration is a change in velocity, I impress upon my students that this includes speeding up, slowing down, and changing direction.  With regards to Mario Kart, I explain what statistics are important for varying circumstances and how stacking one statistic is usually a recipe for disaster.

Lesson for the day...go with Yoshi...or Dry Bones.