12.1 12.1 - Distance and Time VOCABULARY time interval slope Distance is commonly measured in metres (m). Distances between two points can Time (t) is the duration of an event. Time is often referred to as a and given the symbol t. DO QUESTIONS 1-7 pg. 345 CYU

Period & Frequency A period (T ) is , such as a pendulum swinging. It is related to frequency as: Read Sample Problem #1 p. 343 then DO CYU #8-10 p. 345

12.2 12.2Speed VOCABULARY speed average speed instantaneous speed By relating time and distance, we can determine speed, which is the distance an object travels (d) divided by the time interval (t). The average speed of an object is the total distance the object travelled divided by the total time taken. Instantaneous speed For an object travelling at a constant speed (i.e. uniform motion), the average speed is equal to its instantaneous speed.

***Be sure to really think about what the graph ACTUALLY represents*** Graphs are used to ***Be sure to really think about what the graph ACTUALLY represents*** Recall x and y

Graphing Distance and Time 12.3 Graphing Distance and Time A distance–time graph has distance on the y-axis and time on the x-axis. The slope of a line on a distance– time graph is . The units for the slope would be metres/second (m/s), the same as speed. Do CYU 12.2 p. 350

Graphing Distance and Time 12.3 Graphing Distance and Time We can calculate the instantaneous speed of an object at a particular time by calculating the to the line of the distance–time graph of the object’s motion.

Just as we can use distance and time data to construct a graph, we can derive information about distance, time, and speed from a graph. Calculate: The distance travelled between t=0.5hr and t=1.25 hr The average speed over the first 1.75 hr The speed the car is travelling at at t= 0.25 hr and also t = 2.25 hr In words write a description of the cars movement over the 2.5 hr interval in terms of speed, time and distance

12.4-Displacement, Time, and Velocity Quantities can be either scalar or vector. Scalar quantities only have magnitude, which is a number with a unit. Vector quantities have both a magnitude and a direction. An object’s speed and velocity can be described in different ways. For example, average speed or velocity, instantaneous speed, and uniform motion (constant speed or velocity).

Displacement and Velocity 12.4 Displacement and Velocity VOCABULARY scalar quantity displacement vector quantity velocity uniform motion Distance and displacement are similar, but not identical concepts in science. Distance is a scalar quantity (magnitude only). Displacement is a vector quantity (magnitude and direction) The displacement of an object is its change in position in relation to a point of reference.

12.4Displacement, Time, and Velocity The motion of an object can be described by displacement, time, and velocity. Distance and displacement are similar but not identical concepts in science. Speed and velocity are also similar but not identical concepts.

Displacement and Velocity 12.4 Displacement and Velocity VOCABULARY scalar quantity displacement vector quantity velocity uniform motion Speed and velocity are also similar, but not identical concepts. Speed is a scalar quantity (magnitude only). Velocity is a vector quantity (magnitude and direction). Velocity is the rate of change of displacement and is given by the equation: The slope of the line of a position– time graph is equal to the velocity of the object.

Displacement, Time, and Velocity CHAPTER Displacement, Time, and Velocity 12 Distance–time graphs and position–time graphs can visually display information about an object’s motion. The slope of the line is equal to the speed or velocity of the object. If the slope of the line is changing, the speed or velocity is not constant. If the slope the line is constant, the object is travelling at constant speed or velocity.

Displacement, Time, and Velocity CHAPTER Displacement, Time, and Velocity 12 Key Ideas