The Science of Juggling and Hula-hooping!

5 07 2012

Last week at the Museum, young boys and girls participated in our Secret Scientists camp.  On Tuesday, we had a field trip to Sky Candy, an aerial acrobatics company based here in Austin. At Sky Candy, two aerial artists, Danny and Winnie, told us about the science behind different parts of their work.

First, they talked about stretching and our bodies’ muscles.  Do you know the names of any muscles?  We talked about many different muscles and how stretching all of our muscles is important before any kind of exercise.

Here we stretched our triceps (the undersides of our arms).

Then, we talked about the science behind juggling. When you juggle, you are working with gravity.  When you throw the balls up into the air, you go against gravity.  Once the balls hit their peak, they no longer have any force against gravity and begin to fall with the force of gravity.

Trying to learn how to juggle!

After juggling with similar-sized balls, Danny, one of the aerial artists, asked if we thought that a larger ball would fall faster than a smaller one.  What do you think?

Danny with two different-sized juggling balls.

Because gravity works the same on every object, all objects fall at the same speed.  It’s only when an object has wind resistance that its speed may change.  This means that an open, flat piece of paper (which has a large surface that slows down its speed) falls slower than a bowling ball or a marble which fall at the same speed (because their shapes do not resist the force of their fall).

After juggling, Winnie talked to us about the hidden science behind hula-hoops.  When you hula-hoop, your body oscillates (moves from side to side).  This movement creates a force, which is called centripetal force, that acts upon the hoop.  Centripetal force is the force which carries an object (the hoop) on a curved path because of the force’s direction towards the center of the curved path. Thus, your hula-hoop rotates around you on a curved path because your body creates a force with its movement.

Here everyone took turns hula-hooping.

Who knew so much science was a part of aerial acrobats? Just by stretching and tossing a few balls in the air or playing with your hula-hoop at home, you can encounter scientific ideas about the muscles of your body, can see how gravity affects objects, and can create centripetal force.  Thanks to Winnie and Danny for teaching us all of this!!


Gravity Well

12 09 2011

Watch the coin orbit!

The Gravity Well here at The Austin Children’s Museum teaches us about energy. When the coin drops lower into the well some of its gravitational potential energy is converted into kinetic energy. As the coin drops down it has higher velocity. Also, the coin goes around in smaller circles the lower it gets. So you can see how the coin completes orbits much faster near the center of the well, just like a planet would orbiting around the sun!

Make your own gravity well:

What you need:

  • large piece of paper
  • pencil
  • ruler
  • scissors
  • various balls
  • tape
  • paper tube

Experiment with balls or marbles of all shapes and sizes and send us your results. Do the heavier ones travel faster? What about the smaller ones?

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Send us your pics of your homemade gravity wells!

Why Do Golf Balls Have Dimples?

9 09 2011

To Break Wind!

Golf Ball from kainet on flickr

As funny as it seems, golf balls really do have dimples in order to break the wind. How Stuff Works explains the reasoning:

In the early days of golf, smooth-surfaced balls were used until golfers discovered that old, bumpy balls traveled longer distances. The science of aerodynamics helps explain the dimpled phenomenon. The dimples reduce the drag on a golf ball by redirecting more air pressure behind the golf ball rather than in front of it. The higher levels of pressure behind the golf balls force them to go far distances.

The dimples maximize the distance golf balls travel. Dimpled balls travel up to four times farther than smooth-surfaced golf balls!

The dimples change the levels of pressure by bringing the main air stream very close to the surface of the golf ball. The dimples (or “turbulators”) increase the turbulence in the layer of air next to the surface of the ball. This high-speed air stream near the ball increases the amount of pressure behind the ball, forcing the ball to travel farther.

Here at The Austin Children’s Museum we show the aerodynamics of golf balls in our Ready, Set, Roll exhibit. Come check it out before it leaves on September 18th, golf balls have never had so much fun!

Rockin’ and Rollin’ on a Big Roller Coaster

16 08 2011

The month of August is here and the end of summer vacation is near. Have you enjoyed our Ready, Set, Roll exhibit? There are so many components that allow you to challenge the science of physics with some hands-on experimentation.

A few of the games you can play are the Loop d’ Loop where you send a golf ball on an upside down ride, a Ski Jump where you launch a golf ball attempting a land on another ramp, and there’s also the Big Spiral that will make the ball very, very dizzy. There are a ton of other games to play with that give you the chance to have fun while learning physics.

We also have a Roller Coaster that allows a ball to roll from the top of the track through hills and valleys and to the end. Do you know about the physics of roller coasters?

The higher you start the ball on the Roller Coaster track, the better chance it has making it over the first hill. The higher the ball’s starting point, the greater the energy it has at the bottom. On top of each hill, the amount of energy the ball has is called potential energy. Physics4Kids will teach you about potential energy.

The Humor Writer tells us that “physics is the scientific study of many things, such as motion, force, energy, light and sound. It includes gravity, friction and speed – all things that contribute to the way roller coasters operate”. Humor Writer also teaches us about the history of roller coasters.

This is a picture of the oldest working roller coaster Leap-the-Dips in Altoona, Pennsylvania, it’s 109 years old. Built in 1902 by the E. Joy Morris Company and in 1996 was named a National Historic Landmark. It is also the last known example of a Side Friction Figure Eight roller coaster. That means that it is made up of low flat turns and long straightaways with small dips in the the track. There aren’t many of these roller coasters left but learning about the way they have changed throughout the years is interesting.

Speaking of interesting… did you know that August 16th is Roller Coaster Day? Maybe celebrate by going to a theme park or make your very own roller coaster. Zoom gives instructions on how to make one. Send us a picture or let us know what you like about roller coasters!

Zip Line!

4 03 2011

Create a few characters, then send them whizzing down this miniature zip line! We decided to try our hand at Made by Joel’s zip line toy. All you need is a big paper clip, a metal spool, a few smaller paperclips, string, and some paper & pens.

Bend the large paperclip and attach the spool. Draw your characters and sandwich a paperclip between their front & back panels, bending and poking one end of the paperclip through the paper to make a hook above the character’s head.

Bend two more paperclips, then tape them to the wall. Tie each end of a piece of string or fishing line to one of the paperclips. Your zip line is now ready for use. Hook on one of your characters and let it ride!

Refrigerator Fun!

23 02 2011

We made a marble run on our refrigerator!

All you need to make one on your refrigerator is:

  • toilet paper or paper towel tubes (plus scissors to cut them)
  • an empty egg carton
  • a marble
  • magnets

We built a circuit that lights up an LED light into the end of our track. What other cool things can you come up with to include?

Ready, Set, Roll!

28 01 2011

This week we are installing a new exhibit, Ready, Set, Roll! This time, we’re not just borrowing an exhibit from another museum, the talented staff in our shop actually built all of the fun components. Check out these are photos of the exhibit being built in our shop.

This exhibit is meant to help everyone learn more about physics. The components of Ready, Set, Roll! such as The Roller Coaster and The Big U provides hands on experimentation to help us learn about velocity, friction and energy.  Learn more about these words after the jump! Read the rest of this entry »