Sports Chapter 2: Physics in Action

Chapter Challenge
Students become sports broadcasters for PBS. They must compose a voice-over dub for a sports video of their choice. Their video must convey the excitement of the sport and the physics principles observed.

Chapter Summary
To gain knowledge and understanding of physics principles necessary to meet this challenge, students work collaboratively on activities in which they apply concepts of Newton's laws, forces, friction, and momentum to sporting events. These experiences engage students in the content identified in the National Science Education Standards.

Activity Summaries

Physics Principles

Activity One: A Running Start

Students measure the motion of a ball rolling down and up the sides of a bowl and find the ratio of the "running start" to the vertical distance. From this they are introduced to the concept of inertia.

• Acceleration
• Gravity
• Galileo's Principle of Inertia
• Newton's First Law of Motion

Activity Two: Push or Pull

Students construct, calibrate, and use a simple force meter to explore the variables involved in throwing a shot put. They then connect their observations and data to a study of the laws of motion.

• Newton's Second Law of Motion
• Relationship of mass and force to acceleration
• Gravity

Activity Three: Center of Mass

By finding the balancing points on objects with a variety of shapes, students are introduced to the effects of motion the athlete's center of mass has on the balance and performance.

• Center of Mass
• Gravity

Activity Four: Defy Gravity

Students learn to measure hang time and analyze vertical jumps of athletes using slow-motion videos. This introduces the concept that work when jumping is force applied against gravity.

• Gravity
• Potential and kinetic energy
• Work
• Vertical accelerated motion

Activity Five: Run and Jump

Thinking about the direction in which they apply force to move in a desired way introduces students to the concept that a force has an equal and opposite force. They test this concept, then apply it to a variety of motions observed in sports.

• Force Vectors
• Weight and gravity of forces
• Newton's Third Law of Motion

Activity Six: The Mu of the Shoe

Students measure the amount of force necessary to slide athletic shoes on a variety of surfaces. From this and the weight of the shoe, they learn to calculate friction coefficients. They then consider the effects of friction on the athlete's performance.

• Gravity
• Frictional force
• Normal force
• Coefficient of sliding friction

Activity Seven: Concentrating on Collisions

Students investigate the effects of a ball's velocity on its motion after a collision. They then apply these observations and what they now know about opposing forces in motion to describe collisions of balls and athletes in sporting events.

• Newton's Third Law of Motion
• Mass
• Velocity
• Momentum

Activity Eight: Conservation of Momentum

Additional collisions between objects allow students to investigate what happens when the objects stay together or "stick" after the collision.

• Newton's Third Law of Motion
• Momentum = Mass x Velocity
• Law of Conservation of Momentum

Activity Nine: Circular Motion

Students use an accelerometer to test the direction of acceleration when spinning in a chair. From this, they investigate the forces involved in the movement of turning objects and athletes.

• Inertia
• Centripetal acceleration
• Centripetal force