Motion Science 10 Motion Motion is the change

Motion Science 10

Motion ► Motion is the change of an object’s location during a period of time ► An applied force often causes motion

Motion continued ► Motion can be one dimension § Dropping a ball: the ball falls vertically = one direction ► Motion can be two dimensions § Throwing a ball: the ball falls vertically and moves horizontally ► Motion can be circular § Moon’s orbit around Earth

Key Terms: ► Reference point: a starting point used to describe the location / position of an object § The initial point ► Distance: d the total length between two points or the total length travelled including every twist and turn travelled ► Position: an object’s distance and direction from a reference point

Key Terms: ► Scalar: a quantity that has only magnitude (size) (no direction) § Distance, time and temperature all scalars ►Example: 30 km/h ► Vector: a quantity that has both magnitude (size) and direction § Displacement and position are both vectors § Vectors are shown with an → above the letter ►Example: 30 km/h [West]

Distance ► The standard unit for distance is the meter (m) ► Symbols: d (distance) (initial distance) (final distance) (change in distance) ► Delta ( ): means change in So:

Position ► Position: Describes an object’s location, as seen by an observer from a particular viewpoint. ► Symbols: : initial position : final position ► Standard unit: meter (m) § Example: The school is 200 m [E] of Sarah’s house

Distance / Position Time Graph Position = 0 : reference point Positive Position: Distance up or right from the reference point ► Negative Position: Distance down or left from the reference point ► ►

Direction ► Direction: Objects that move in a straight line, in only one dimension, either backwards or forwards or up or down is called linear motion. Direction is shown using a + or a -. § A + indicates up or to the right of the starting point (can also be north or east) § A – indicates down or to the left of the starting point ( can also be south or west)

Examples: • The reference point is the hydrant because it is at 0 m • When the runner is at 9 m her position is +9 m • When the runner is 5 m west of the hydrant position is -5 m West East

Displacement ► Displacement: the change in position: the difference between initial position and final position § Describes how much an objects position has changed § Measures the shortest path (straight line from initial position to final position) § Displacement is a vector (has both magnitude and direction) ►If an object ends up exactly where it started, like a runner running around a track, the displacement is zero, even if it has moved a long way.

Displacement ► Symbols: ► (change in position or displacement) So:

Displacement ► Example: ► Than: and

Time Describes when an event occurs ► Standard unit is the second (s) ► Time interval describes the duration of an event ► Time is a scalar since it does not have direction ► § ► Example: 50 s Symbols: t (time) (initial time) (final time) (time interval) So:

Distance vs Time