Top of page

# Launching Units with Primary Source Phenomena: Like a Shot from a Bow

This post is coauthored by Jackie Katz, 2022 Albert Einstein Distinguished Educator Fellow at the LOC and Laura Akesson, 2022 Albert Einstein Distinguished Educator Fellow at the Department of Energy. It is one in a series focused on using primary sources as phenomena in STEM classes.

Have you considered using primary sources as launching phenomena in your classroom? Primary sources often present a puzzle to be solved; the content related to your discipline can help put the pieces together. For example, in a physics classroom students can explore the photograph “Like a Shot from a Bow” when launching a unit on equilibrium and torque to learn about gravity, equilibrium, and force.

This image was taken by Leonid Zhdanov, who was both a dancer and photographer, when observing the Bolshoi Theater rehearse “The Rite of Spring” in 1965. The captured lift might seem to defy the laws of physics, but close observation suggests that an astute awareness of physics makes this lift possible. Many other images of dancers that seem to defy the laws of physics can be found within the Library’s performing arts digital collections.

Present this image to your students at the start of the unit and ask them to observe, reflect, and question. Students can organize their thoughts on the Primary Source Analysis Tool. Students may ask “How is this lift possible?” as a result of their observations. If not, ask this driving question after they have shared their observations, reflections, and questions.

Provide students time to reflect on their prior knowledge and offer up possible concepts that might answer this driving question. Students might make connections to the concepts of gravity, equilibrium, or force. Once students make connections to prior knowledge, ask them what in the image they need to explain to develop a complete answer to the driving question. Possible responses include:

• Why are the legs of the lifter so far apart?
• Why is the left hand of the lifter on the ankle of the lifted?
• Where is the right hand of the lifter? Why?
• Why is the lifted dancer leaning backward rather than forward?

If students do not ask these questions on their own, focus their attention on the dancers’ posture and the position of their hands and feet, allowing more time for observation and reflection with the primary source analysis tool.

To answer these questions, students can work through activities that address the concepts of center of mass, torque, force, and equilibrium. The activities could include practice drawing free body/force diagrams or have students explain the stability of a bicycle versus a tricycle. As the class progresses through each of these activities, revisit the list of questions. What has each activity contributed to their understanding of the driving question?

At the end of the unit, ask students to annotate the image (consider using a digital tool) to explain the physics concepts that make a lift like this possible. Using mass and distance estimates, students may calculate the forces and torques involved. Depending on when in the year this unit falls, you can also consider having students reflect on the title of the image. How might this lift be similar to shooting a bow? Students will need to make predictions about how the dancers arrived at this position and how energy is transferred in both instances.

By framing a physics unit with dance, students will see how the concepts they learn in physics can be applied to explain the world around them.

Do you enjoy these posts? Subscribe! You’ll receive free teaching ideas and primary sources from the Library of Congress.