The film’s humor serves both to hold students’ interest and to demonstrate the concepts being discussed. Ivey - and the camera - are indeed inverted. Only when the pair flip a coin does it become obvious that Dr.

Hume, who appears to be upside down, accusing Dr. In the film University of Toronto physics professors Patterson Hume and Donald Ivey explain the distinction between inertial and nonintertial frames of reference, while demonstrating these concepts through humorous camera tricks. The film was made to be shown in high school physics courses. In this classic film, Professors Hume and Ivey cleverly illustrate reference frames and distinguish between fixed and moving frames of reference.įrames of Reference (1960) Educational Film: Frames of Reference is a 1960 educational film by Physical Sciences Study Committee. Frames of reference are particularly important when describing an object’s displacement.įRAMES OF REFERENCE by Professor Hume and Professor Donald Ivey of the University of Toronto It might seem strange to use a coordinate system moving relative to the earth - but, for instance, the frame of reference moving along with a train might be far more convenient for describing things happening inside the train. But this shows that there is a third arbitrary choice that goes into choosing a coordinate system: valid frames of reference can differ from each other by moving relative to one another. Most people would say that they just failed to notice that the train was moving - it only seemed like the station was moving. Imagine sitting in a train in a station when suddenly you notice that the station is moving backward. But you don’t want to change coordinate systems in the middle of a calculation. As long as you are consistent, any frame is equally valid. This is referred to as choosing a coordinate system, or choosing a frame of reference. You have to decide where to put x = 0 and which direction will be positive. There are two choices you have to make in order to define a position variable x. The physical quantities relevant to the motion of a particle include: mass m, position r, velocity v, acceleration a. Kinematics of a particle trajectory: Kinematic equations can be used to calculate the trajectory of particles or objects. The study of kinematics can be abstracted into purely mathematical expressions, which can be used to calculate various aspects of motion such as velocity, acceleration, displacement, time, and trajectory. Kinematic analysis is the process of measuring the kinematic quantities used to describe motion. The word “kinematics” comes from a Greek word “kinesis” meaning motion, and is related to other English words such as “cinema” (movies) and “kinesiology” (the study of human motion). Kinematics is used in astrophysics to describe the motion of celestial bodies and systems and in mechanical engineering, robotics and biomechanics to describe the motion of systems composed of joined parts (such as an engine, a robotic arm, or the skeleton of the human body).Ī formal study of physics begins with kinematics. To describe motion, kinematics studies the trajectories of points, lines and other geometric objects, as well as their differential properties (such as velocity and acceleration). An understanding of acceleration, for example, is crucial to the study of force. Interesting questions about motion can arise: how long will it take for a space probe to travel to Mars? Where will a football land if thrown at a certain angle? An understanding of motion, however, is also key to understanding other concepts in physics. Even in inanimate objects there is continuous motion in the vibrations of atoms and molecules. When you are resting, your heart moves blood through your veins. Everything from a tennis match to a space-probe flyby of the planet Neptune involves motion. The study of kinematics is often referred to as the “geometry of motion.” Kinematics is the branch of classical mechanics that describes the motion of points, objects and systems of groups of objects, without reference to the causes of motion (i.e., forces ).

Unit 3 stacks of kinematics curves