Chapter 2.1

Motion in One Dimension

Branches of Physics

• Dynamics – branch of study concerned with the study of motion• Kinematics – part of dynamics that

describes motion without regard to its causes

Velocity

• Average velocity is defined as displacement divided by the time interval during which the displacement occurs• SI unit is meters per second (m/s)• Can be positive or negative

Displacement and Velocity

• Defined as a change in position• Not always equal to distance traveled• Can be positive or negative• Calculated by final position – initial

position–Delta X

Velocity and Speed• Velocity describes motion with both a

direction and a numerical value (magnitude)

• For any position vs. time graph, we can determine the average velocity by drawing a straight line between any two points on the graph

• Speed has no direction, only magnitude• Speed = distance traveled divided by the

time interval for the motion

• Instantaneous velocity -