Below are the instructions to some activities I have created. These instructions are from the "Physics for Dancers" section of my book, The Physics of Dance. Have fun exploring!
Discover the relationship between time and vertical height when jumping to different tempos.
· Materials: metronome
· Set the metronome to 75 bpm and sauté on the clicks. Repeat at 130 bpm.
· Ask the audience at which tempo can they get higher in the air when they sauté.
· Expected response, “I can jump higher with the slower tempo.”
· Explanation: Based on physics principles of kinematics, if you have a longer time period that an object is in the air, it has the potential to reach a higher height than giving that same object a shorter time of flight. For this reason ,when you jump to the slower tempo (therefore giving yourself more time of flight), you can jump higher on the beat than when jumping to the faster tempo.
· Use your music! If you do a combination to a slower song, utilize the extra time you have to jump higher than you would be able to in a fast song.
· Taking it further: Try royales and entrechat quatres to demonstrate different ways of jumping vertically in time.
Discover the difference between distance and displacement.
· Materials: rice, tin foil trays (8x8 works well), toothpick flags
· Set-Up: Fill the trays with a layer of rice (enough to cover the entire bottom). Tape the toothpick flags to opposite corners of the trays.
· Directions: Tell the audience to start with a finger in the rice at one flag and to draw a swirly/zig-zag path to the second flag.
· Expected response: everyone could have a different path
· Discuss how displacement would be the measure if you placed your finger from the first flag directly to the second while distance is the measure of the whole path your finger took, sticking to its own path
· Discuss how in a dance, different paths can be taken so that dancers travel to the same spot from the same spot (equal displacement), but they all may travel different ways to make it more appealing to the eye (different distances).
Discover center of mass with small objects
· Materials: pencils, pens, or small/long objects
· Exploration: First ask where they expect the center of mass to be and let them try to discover it independently with the objects.
· Demonstration: Show how you put your fingers on the ends of the object and slowly move them towards the center. The balance point is approximately the center of mass.
· Challenge: If you try to find the center of mass of a pencil with a heavy eraser, will the center of mass be at the center of the pencil? The answer is no because the eraser adds a lot of mass. As a result, the center of mass will be shifted away from the center of the pencil in the direction of the eraser.
Discover the directions and effects of applied forces.
· Materials: none
· Partner up
· Have partners hold up their right hands and put them together. Then they need to gently press their hands together. This demonstrates a force being applied by each partner. Naturally, the forces are directed in opposite directions due to the fact that one partner pushes in a direction and the other partner pushes in the direction directly opposite.
· If the forces are equal and opposite, their hands will not move; however, if their forces are unbalanced, their hands will move.
· Taking it further: Try the activity again but with partners putting their backs to one another. The goal is to try to be stronger than your partner so they move. This further demonstrates balancing forces because if one partner applies a stronger force, both partners will move.
· Taking it even further: You can think of friction like your partner’s hand/back as it inhibits you from sliding the direction you want to slide. Continue to the next activity for more information about friction.
Discover relationship between friction and types of surfaces/ footwear
· Materials: rubber jar openers, fabric circles
· Experiment with sliding the different materials on the floor.
· Expected Response: The fabric slides more easily.
· Explanation: It’s easiest to slide with a slippery surface instead of the rougher one because less friction is created with a slick surface. Friction occurs between surfaces that contact one another. This contact can create the resulting friction force which can slow down the speed of an object’s motion.
· Alternate demonstration opportunity: You could try sliding different types of dance shoes across the floor to see which create the most friction. Good shoes to use would be tap shoes, pointe shoes, and jazz shoes.
· Relate the experience with the activity to real life. For example, pretending to be an ice skater by slipping around in socks on the kitchen floor versus trying to do the same thing in tennis shoes. You would slide much more in socks because less friction is created.
· More advanced: Discuss ways dancers try to create more friction with rosin/hairspray to avoid slipping on stage.