Home > Courses > 1P21_Crandles > Kinematics Mechanics and Waves Introduction Kinematics: Describing Motion Motion Diagrams (Trajectories) Position, Displacement, Distance Travelled Vectors vs. Scalars MC: positive and negative displacements MC: displacement vs. distance travelled Speed, Average Velocity, Instantaneous Velocity Ex: a cyclist Ex: skydiver Several Ways to Represent of Motion Ex: Walking to School (in words) as: Data Table (assume walking along x-axis) as: Motion Diagram as: Position versus time graph as: Continuous Position versus time graph Position versus time graphs Position versus time graphs are NOT trajectories. uniform velocity vs. non-uniform velocity graphical representation of average and instantaneous velocity MC: motion diagram and graph MC: instantaneous velocity from xt graphs Ex: average velocity Acceleration Velocity versus time graphs calculating uniform acceleration from v.vs.t graphs MC: Where is the acceleration zero? MC: car brakes then continues at reduced speed MC: x-t graph from v-t graph Constant acceleration (1-D problems) zero acceleration versus constant acceleration Kinematic Equations Ex: displacement of an accelerating boat Ex: an accelerating spacecraft Falling Objects falling in a vacuum MC: falling objects I MC: falling objects II Ex: a diver problem Ex: catching a ball Ex: two stones Motion in 2D and 3D Vectors Multiplying Vectors by a scalar Adding Vectors graphical vector addition subtraction is a form of addition MC: Add two vectors Unit Vectors and Components unit vectors define a coordinate system resolving vectors into scalar components Ex: Find the components adding vectors via components (or this or this) vector components and trigonometry Ex: determine these components Displacement, Velocity and Acceleration in 2D and 3D Displacement Velocity Ex: a flying bat MC: Where is the object? Acceleration MC: uniform speed, curved path, what is direction of acceleration? Ex: average vector acceleration Constant acceleration (projectile motion) x-motion is independent of y-motion I x-motion is independent of y-motion II x-motion is independent of y-motion III MC: Which strikes the ground first? MC: peak of trajectory I MC: peak of trajectory II MC: acceleration during projectile motion MC: smallest speed during projectile motion Applying the kinematic equations Ex: dropping a lifeboat (projectile motion) Ex: pitcher's mound Ex: a daredevil jumping over buses Dynamics Rotational motion Work, energy, momentum Oscillations and waves