# You know an object is in motion if it is changing position.

## Presentation on theme: "You know an object is in motion if it is changing position."— Presentation transcript:

You know an object is in motion if it is changing position.
Matter and Motion You know an object is in motion if it is changing position. You know an object is changing position if it moves relative to a reference point.

Distance and Displacement
Distance is the length of the route you will travel. Displacement is the direction and difference in position between your starting and ending points.

Distance and Displacement
On your notes page, draw two examples of displacement. The first one with a displacement of zero, and the other with a displacement of 10 meters. Turn to your partner to check your drawings.

Speed = distance (d) / time (t)
Speed (v) = the distance an object travels in a unit of time. (How rapidly a distance is covered.) Speed = distance (d) / time (t) units are m/s

Draw Picture of the formula triangle
v= d/t

Practice Problems A runner completes a 400-m race in 43.9 s. In a 100-m race, he finishes in 10.4 s. In which race was his speed faster? A passenger train travels from Boston to New York, a distance of 350 km, in 3.5 h. What is the train’s speed?

Average Speed/Instantaneous Speed
Average speed = total distance traveled divided by the total time taken. Instantaneous speed is the speed of an object at one instant of time.

Graphing Motion We will be working with Distance-Time graphs. For this type of graph, time is plotted on the horizontal axis and distance is plotted on the vertical axis.

Graphing Motion Copy the chart below onto your notes page, and create a Distance-Time graph using the information. Bicycle Race Data Time (h) Distance (km) 1 8 2 16 3 24 4 32 5 40

Velocity = speed in a given direction. (magnitude & acceleration)
Example: flying at 600 km/h east Driving at 120 km/h south Question: Could you use a distance-time graph to show velocity? Why or why not?

Velocity Answer: No, because a distance-time graph would not show the direction of motion

Average Classes Stop Notes Here. Just Discuss 

Combining Velocities example:
Rowing down a river River = 15 m/s You paddle down 4m/s Velocities combine, your total velocity is 19 m/s down stream.

Acceleration = to change in velocity / time to make change.
Acceleration = rate of change of velocity. (ex. Car changing speed & direction…swerving) Velocity = (final velocity – original velocity) Acceleration = to change in velocity / time to make change.

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