the Public Broadcasting Service
the Show of Force Productions
This video-based resource examines centripetal force through the motion of circus animals running around a ring. Objects moving in a circle (even at constant speed) are experiencing acceleration because the center-seeking force causes a change in velocity. The video can serve to help students understand that an unbalanced force can change the direction of the velocity vector but not its magnitude. It includes tips on how to incorporate the video into instruction, discussion questions, and accompanying classroom activities.
This resource was developed in conjunction with the PBS series Circus. See Related Materials for a link to the full set of 8 Circus Physics video-based lessons.
center-seeking force, centripetal force videos, circular motion, circular motion videos, motion videos, physics videos, video analysis, video-based learning
Metadata instance created
November 19, 2013
by Caroline Hall
August 4, 2016
by Lyle Barbato
AAAS Benchmark Alignments (2008 Version)
4. The Physical Setting
6-8: 4F/M3b. If a force acts towards a single center, the object's path may curve into an orbit around the center.
9-12: 4F/H1. The change in motion (direction or speed) of an object is proportional to the applied force and inversely proportional to the mass.
9-12: 4F/H4. Whenever one thing exerts a force on another, an equal amount of force is exerted back on it.
9-12: 4F/H8. Any object maintains a constant speed and direction of motion unless an unbalanced outside force acts on it.
11. Common Themes
11C. Constancy and Change
9-12: 11C/H4. Graphs and equations are useful (and often equivalent) ways for depicting and analyzing patterns of change.
Next Generation Science Standards
Motion and Stability: Forces and Interactions (HS-PS2)
Students who demonstrate understanding can: (9-12)
Analyze data to support the claim that Newton's second law of motion describes the mathematical relationship among the net force on a macroscopic object, its mass, and its acceleration. (HS-PS2-1)
Disciplinary Core Ideas (K-12)
Forces and Motion (PS2.A)
The motion of an object is determined by the sum of the forces acting on it; if the total force on the object is not zero, its motion will change. The greater the mass of the object, the greater the force needed to achieve the same change in motion. For any given object, a larger force causes a larger change in motion. (6-8)
Newton's second law accurately predicts changes in the motion of macroscopic objects. (9-12)
Relationship Between Energy and Forces (PS3.C)
When two objects interact, each one exerts a force on the other that can cause energy to be transferred to or from the object. (6-8)
NGSS Science and Engineering Practices (K-12)
Using Mathematics and Computational Thinking (5-12)
Mathematical and computational thinking at the 9–12 level builds on K–8 and progresses to using algebraic thinking and analysis, a range of linear and nonlinear functions including trigonometric functions, exponentials and logarithms, and computational tools for statistical analysis to analyze, represent, and model data. Simple computational simulations are created and used based on mathematical models of basic assumptions. (9-12)
Use mathematical representations of phenomena or design solutions to support and revise explanations. (9-12)
Common Core State Standards for Mathematics Alignments
High School — Algebra (9-12)
Seeing Structure in Expressions (9-12)
A-SSE.1.a Interpret parts of an expression, such as terms, factors, and coefficients.
High School — Geometry (9-12)
G-C.2 Identify and describe relationships among inscribed angles, radii, and chords.
Circus Physics: Centripetal Acceleration. (2010). Retrieved April 24, 2017, from Public Broadcasting Service: http://www.pbslearningmedia.org/resource/6b92cb91-72bb-4d87-a8ea-8171506bde35/6b92cb91-72bb-4d87-a8ea-8171506bde35/
Show of Force Productions. Circus Physics: Centripetal Acceleration. Arlington: Public Broadcasting Service, 2010. http://www.pbslearningmedia.org/resource/6b92cb91-72bb-4d87-a8ea-8171506bde35/6b92cb91-72bb-4d87-a8ea-8171506bde35/ (accessed 24 April 2017).
Circus Physics: Centripetal Acceleration. Arlington: Public Broadcasting Service, 2010. Show of Force Productions. 24 Apr. 2017 <http://www.pbslearningmedia.org/resource/6b92cb91-72bb-4d87-a8ea-8171506bde35/6b92cb91-72bb-4d87-a8ea-8171506bde35/>.
%0 Electronic Source %D 2010 %T Circus Physics: Centripetal Acceleration %I Public Broadcasting Service %V 2017 %N 24 April 2017 %9 application/flash %U http://www.pbslearningmedia.org/resource/6b92cb91-72bb-4d87-a8ea-8171506bde35/6b92cb91-72bb-4d87-a8ea-8171506bde35/
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