LEAFLET: Physics with Pizzazz! Part B

 

DID YOU KNOW THAT

YOU CAN LEARN PHYSICS

THROUGH SHOWMANSHIP?

Start to learn about some basic science involved in doing

demonstrations that are fun – 

Physics With Pizzazz!

Part B

 

We look at the following questions: 

·        How can I speed up and slow down a rotating chair with friction?

·        How can a football spinning on the ground stand up on its end –   

in other words, how can it change its axis of rotation?

  http://sportscience-kathy.blogspot.com

GATEWAY TO SCIENCE:

SPORTS AND GAMES

Quincy, Mass.

Page 1

INTRODUCTION

Do you like to perform for people?  Try this!  A little showmanship goes a long way in this approach that leads people to physics in a fun way.  Here’s a suggested script to get you started.

YOU:   THIS IS PHYSICS WITH PIZZAZZ!  Today we’ve got some games – a few challenges – for you!  Well, you may say, “What’s the big deal about a chair and a football?”  Well, let’s find out!

You Need:   a swivel chair  (one with no arms is preferable)

1st Challenge. Who would like to go for a spin on this swivel chair?  (Ask a volunteer to sit on the chair.)

Ask:  Does anyone think that this chair can speed up or slow down when it rotates?  And I mean speed up or slow down without any help from me.

(Optional:  If anyone says Yes, see if they can explain it.) 

Then have the seated volunteer place their hands on their lap.  Feet should rest on the base of the chair, not on the floor (see illustration). 

Give the seated person a good push. 

Then tell them to put out their arms >>>  slow down.

Tell the person to bring in their arms >>>  should speed up.

Explanation:  First of all, contact  of one  OBJECT  with another OBJECT produces friction.  (Demonstrate rubbing your hands.)

In this case, contact of an OBJECT with an outside FORCE produces friction, too. 

Air resistance is a FORCE caused by air.  (Blow on your hands.) 

Friction slows down things in motion.  So, putting the arms out gives more surface to be in contact with the air, and this increases the friction    (slows things down);

Bringing in the arms gives less surface in contact with air, and this decreases friction (speeds things up).

That’s why birds and airplanes – and footballs – have an aerodynamic shape.

Page 2

2^nd Challenge.

 You Need:  a football – a proper football was found to work better than a small spongy toy football

YOU:  Speaking of footballs, I am challenging you to spin this football  on the floor so fast that it stands up on its pointed end.   Can you do it?

By doing this, you change the axis of rotation from a short one (when it’s lying flat) to a long one (when it’s standing up on its “toe”).  

# GEOGRAPHY REVIEW #

Remember how we say the Earth spins on its axis of rotation 

(an imaginary line through the center of the planet)?  Same idea!

Page 3

Challenges like these are just one of endless ways to gain an understanding of physics and geometry.      I hope this leaflet introduces you to seeing  things  you never saw before –    or wondered about but just didn't know where to start.

 Physics and geometry  come into play in every activity and event going on around us.

Knowing how things work can add to your performance and to your fun.  So give it a try.  How?

 •        Start with the information here

•        You  may  not understand  everything  in it right away, but for  now,  use  what you do understand

•        Do an online search of your own

•        See  what  books  or  videos  your library  has

•        Share them  with friends,  your class, your team, your scout troop

•        Read my blog and tell others: 

                        sportscience-kathy.blogspot.com

                                                                      Thank you! 

                                                Kathy Hogan