Physics 20 Unit 1 Kinematics
Chapter 1: Graphs and equations describe motion in one dimension
The language of motion
Kinematics: Branch of Physics that describes motion
Origin: a reference point for measurement
Position: the straight-line between the origin and an object’s location; includes magnitude and
direction
Scalar quantity: a measurement that has magnitude only
Vector quantity: a measurement that has both magnitude and direction; like position
Distance: the length of the path taken to move from one position to the other
Displacement: a straight line between initial and final positions; includes magnitude and direction
Sign conventions:
Speed: Rate at which the object moves (scalar quantity).
𝑑𝑖𝑠𝑡𝑎𝑛𝑐𝑒(𝑚)
Formula: Speed = 𝑡𝑖𝑚𝑒 (𝑠)
Unit: m/s (S.I. unit)
Velocity: Rate at which the object moves in a direction (vector quantity).
(Vector quantities are show with an arrow sign, so, velocity vector is 𝑣⃗.
𝑑𝑖𝑠𝑝𝑙𝑎𝑐𝑒𝑚𝑒𝑛𝑡 (𝑚)
Formula: Velocity = 𝑡𝑖𝑚𝑒 (𝑠)
Unit: m/s (S.I. unit)
Position time graphs and uniform motion
Slope of a position time graph= average velocity
Uniform velocity: the velocity of an object remains constant.
At rest: No change in position with time
(Graph is a straight horizontal line parallel to x-axis.)
[1] Quicknotes
Chapter 1: Graphs and equations describe motion in one dimension
The language of motion
Kinematics: Branch of Physics that describes motion
Origin: a reference point for measurement
Position: the straight-line between the origin and an object’s location; includes magnitude and
direction
Scalar quantity: a measurement that has magnitude only
Vector quantity: a measurement that has both magnitude and direction; like position
Distance: the length of the path taken to move from one position to the other
Displacement: a straight line between initial and final positions; includes magnitude and direction
Sign conventions:
Speed: Rate at which the object moves (scalar quantity).
𝑑𝑖𝑠𝑡𝑎𝑛𝑐𝑒(𝑚)
Formula: Speed = 𝑡𝑖𝑚𝑒 (𝑠)
Unit: m/s (S.I. unit)
Velocity: Rate at which the object moves in a direction (vector quantity).
(Vector quantities are show with an arrow sign, so, velocity vector is 𝑣⃗.
𝑑𝑖𝑠𝑝𝑙𝑎𝑐𝑒𝑚𝑒𝑛𝑡 (𝑚)
Formula: Velocity = 𝑡𝑖𝑚𝑒 (𝑠)
Unit: m/s (S.I. unit)
Position time graphs and uniform motion
Slope of a position time graph= average velocity
Uniform velocity: the velocity of an object remains constant.
At rest: No change in position with time
(Graph is a straight horizontal line parallel to x-axis.)
[1] Quicknotes
