Vector Kinematics – Terms to Know

     

  1. Mechanics - the study of the motion of objects, forces, and energy – usually divided into fields of kinematics and dynamics.

  2. Kinematics - the study of the description of motion without reference to the causes of the motion.

  3. Dynamics - the study of the the causes of the motion.

     

  4. Magnitude - the size of a quantity (e.g. 5.0 m/s). (S)

     

  5. Scalar - (S) - a quantity specified by magnitude only (e.g. a sped of 3.2 m/s).

     

  6. Vector - (V) - a quantity described by both magnitude and direction (e.g. a velocity of 6.5 m/s North).

     

  7. Distance – interval of space between two points. (S)

     

  8. Displacement – the distance and direction of a point or object from a specified point (usually the origin). (V)

  9. Velocity – rate of change of displacement (Defining equation ). (V)

  10. Speed – rate of change of distance (Defining equation ). (S)

     

  11. Average speed – total distance moved divided by the total time. (S)

     

  12. Resultant – the vector sum of two or more vectors. (V)

     

  13. Component – a vector found using the reverse process of finding the resultant whereby a single vector is resolved into two or more other vectors. (V)

     

  14. Frame Of Reference – the arbitrary “place” from which an observer makes measurements (e.g. the top of a laboratory bench or an airplane or the moon, etc.). (V)

     

  15. Relative Velocity – the velocity an object appears to have to an observer who is moving with a different object. (Relative velocities are calculated by determining the difference between i.e. subtracting, two vectors.)

     

  16. Projectile - an object projected into the air near the Earth’s surface. Projectiles have no power source of their own so their motion is determined only by EXTERNAL forces such as the force of gravity and air resistance.

     

  17. Trajectory - the path followed by a projectile.

  18. Acceleration – the rate of change of velocity (Defining equation ). (V)

  19. Acceleration Due To Gravity – the acceleration of freely falling objects. (Near the surface of the Earth it is about 9.80 m/s2). (V)

     

  20. Range – the horizontal component of the displacement of a projectile from its starting point. (V)