Physics - One Dimensional Motion

Mechanics

Study of the motion of objects. Includes concepts of force and energy.

Kinematics

Descriptions of how objects move

Dynamics

Force and why objects move

Motion

A change in position

Frame of reference

A point against which position is measured. Stage vs. seat

Coordinate system

Tells you when the zero point of the variable and the direction in which the values increase

Scalar quantity

Tells only magnitude. Numbers with units, no direction

Vector quantity

Tells magnitude and direction. Represented with an arrow

Position

Where an object is at any moment in time

Distance

How far an object traveled. It’s a scalar quantity

Displacement

Change in position of an object. Difference between starting position and ending position. Does not depend on the path followed. Has direction.

Delta

Means “change in” and is represented by a greek letter (triangle)

Average Speed

Total distance traveled divided by the time it took to travel the distance.

Velocity

Has magnitude (how fast an object is moving) and direction in which it is moving

Average velocity

Change in position (displacement) divided by the time interval during which the change took place

Instantaneous velocity

Speed and direction at a specific instant in time

Acceleration

How rapidly the velocity of an object is changing

Average acceleration

Change in velocity divided by the time taken

Constant acceleration

Same change in velocity during each time interval

Instantaneous acceleration

Change in velocity at a specific moment in time

Problem solving 1

Read the problem carefully

Problem solving 2

Define: Draw diagram, choose coordinate system. Identify given, unknown

Problem solving 3

Plan: choose an equation, rearrange the equation to solve for unknown variable

Problem solving 4

Calculate: Plug in numbers and solve

Problem solving 5

Evaluate: check units, sig figs, and reasonableness of answer

Free Fall

Acceleration due to gravity.