Conceptual Physics Alive: Vectors & Projectiles

Conceptual Physics Alive: Vectors & Projectiles includes a digital video and questions set with answers. Observe Paul Hewitt teach in a classroom with real students, using engaging demonstrations and artwork. In this video, Paul Hewitt teaches Vectors and Projectiles: Vector addition and vector resolution are explained, using examples such as airplanes flying in the wind and projectile motion. The idea of the independence of the horizontal and vertical components of motion for projectiles is introduced. Vectors & Projectiles Includes: Hewitt begins with a chalkboard discussion of what a vector is. Vectors are drawn to represent the airplane speed- against the wind, with the wind, then crosswind. Hewitt rolls bowling ball across a table, then represents its velocity on chalkboard with vectors. Questions to clarify the concept of the independence of horizontal and vertical motion are posed and explained. Hewitt writes the formulas for acceleration and velocity on the board and discusses numerical examples. Hewitt stresses that the equations of physics are to physics types what sheet music is to musicians. Hewitt draws a vector diagram of the ball rolling off the edge of the table. Only the vertical component of motion changes; the sideways (horizontal) part stays the same. Hewitt demonstrates the independence of horizontal and vertical motion with a device that shoots a ball horizontally while simultaneously dropping another vertically. Then he humorously repeats the demo in "slow motion." Hewitt tells the humorous story of the lonesome person who joins a church group picnic at the cliffs over the ocean, and who tries to answer the question of a delightful person who asks how high the cliff is above the water. The concept that the time it takes for a rock to drop straight down is the same time it takes to drop if thrown horizontally is illustrated. Hewitt draws a sketch of a baseball pitcher who throws a ball horizontally from a tower 5 m tall. The ball lands 25 m downrange. What is the speed of the ball thrown by the pitcher? Hint: Speed= distance/time. [25 m/s.] Would the ball be in the air if the earth's curvature were a factor? [Yes, but for a longer time.] The concept of orbital motion is introduced via the idea of firing a cannonball faster and faster from a mountain top. Hewitt draws an analogy between an orbiting cannonball and the space shuttle. Hewitt guides the class to deriving the speed needed for a cannonball to orbit the earth. This is done by considering the falling of a cannonball fired across a desert floor. The speed is 8 km/s. Hewitt cites the case of a kid who wants to know why satellites don't fall to earth and guides the class to formulating an answer for the kid. SEE RESOURCES TAB FOR A SAMPLE OF NEXT-TIME QUESTIONS AND CLICK HERE FOR MORE Please note: The digital content will be sent to the email provided during checkout, once your order has been processed. Order will be processed no later than the next business day. Digital format: The email you will receive will contain a hyperlink to download a .ZIP file containing a digital video (.MP4) and questions set with answers (.PDF). Notice: The Conceptual Physics Alive Digital content is protected by copyright laws. Replicating and distributing this digital content without the authority of the copyright owner is an infringement of the copyright. This digital content can be used in physical or remote classroom settings (e.g., Google Classroom, Canvas, etc.), or Homeschool.