1. Motion Mrs. Manly 8 th grade science

2. Motion Name Date MotionPosition Occurs when there is a change in position of an object with respect to a reference point. Occurs when there is a change in position of an object with respect to a reference point. The location of an object. The location of an object. An object changes position if it moves relative to a reference point. An object changes position if it moves relative to a reference point. The change in position is determined by the distance and direction of an object’s change in position from the starting point (displacement). The change in position is determined by the distance and direction of an object’s change in position from the starting point (displacement).

3. Motion con’t Reference Reference Point Point Direction Direction A location to which you compare other locations. A location to which you compare other locations. Is the line or path along which something is moving, pointing or aiming. Is the line or path along which something is moving, pointing or aiming. It is measured using a reference point with terms such as up, down, left, right forward, backward, toward away from, North, South, East or West It is measured using a reference point with terms such as up, down, left, right forward, backward, toward away from, North, South, East or West

4. Example of Direction Segment Distance (m) Direction X10East Y7North Z10West Draw a line to scale representing 10 meters in an easterly direction. At the end of that line, draw a line representing 7 meters in a northerly direction. Connect the end of the third line to the 7 meter line traveling 10 m west. Measure the distance and direction from the starting point to the end of the third line. The position at the end of the trip is 7 meters north of the starting point.

5. Motion Con’t Motion can also be described by the Motion can also be described by the relationship between distance relationship between distance an object travels and the period an object travels and the period of time it travels. This of time it travels. This measurement of motion is a measurement of motion is a rate. rate.

6. Motion Con’t Relative Motion Relative Motion Example Example Is determined by the reference point that is chosen. If you are sitting on a bus seat. You are not in motion in reference to the bus seat. However if the bus moves past McCants Middle School, you are in motion in reference to the school.

7. Motion Con’t Speed Speed Is a measure of how fast something moves a particular distance (for ex. Meters) over a given amount of time (for ex. Seconds). Is a measure of how fast something moves a particular distance (for ex. Meters) over a given amount of time (for ex. Seconds). Therefore, speed is a rate of change of a position of an object, or how far something will move in a given period of time. Therefore, speed is a rate of change of a position of an object, or how far something will move in a given period of time. Speed does not necessarily mean something is moving fast. Speed does not necessarily mean something is moving fast.

8. Motion Con’t Calculating Speed Calculating Speed To calculate speed you need to know the distance and time measurements. For ex. A boat travels 25 km in 10minutes. The formula used to calculate speed is speed=distance/time or s=d/t. The above problem would look like this s=25km/10 min. To solve this problem you divide the total distance by the total time. What is the speed of the boat?

9. Speed, distance and time triangle D ST

10. Speed con’t Calculating average speed speed Average speed is calculated by dividing the total distance the object travels by the total amount of time it takes to travel that distance. The speed may vary during the total time an object is moving therefore, the total distance and total time has to be calculated. The speed may vary during the total time an object is moving therefore, the total distance and total time has to be calculated.

11. Speed Graphs Calculating average Calculating average speed speed Speed measurements contain a unit of distance divided by a unit of time. Examples of units of speed might include “meters per second” (m/s), “kilometers per hour” (km/h), or “miles per hour” (mph or mi/hr). Speed measurements contain a unit of distance divided by a unit of time. Examples of units of speed might include “meters per second” (m/s), “kilometers per hour” (km/h), or “miles per hour” (mph or mi/hr).

12. Speed Graphs Calculating average Calculating average speed speed Average speed can be calculated using the formula v=d/t where the variables are: Average speed can be calculated using the formula v=d/t where the variables are: –v is the average speed of the object –d is the total distance or length of the path of the object -- t is the total time taken to cover -- t is the total time taken to cover the path the path

13. Speed con’t Speed Practice Speed Practice An airplane travels 5,000 km in 50 s. What is the speed of the plane? An airplane travels 5,000 km in 50 s. What is the speed of the plane? A rider finishes a 120 km race in 3 hours. What is the speed of the rider? A rider finishes a 120 km race in 3 hours. What is the speed of the rider? An car travels 30 km in 2 hours. Find the speed of the car. An car travels 30 km in 2 hours. Find the speed of the car. Create your own speed problem to share with the class. Create your own speed problem to share with the class.

14. Speed Graphs Time/ Distance graphs Time/ Distance graphs A graph that can be used to represent how both speed and distance change with time. A graph that can be used to represent how both speed and distance change with time. For this type of graph, time (the independent variable) is plotted on the x-axis and the distance (the dependent variable) is plotted on the y- axis. For this type of graph, time (the independent variable) is plotted on the x-axis and the distance (the dependent variable) is plotted on the y- axis.

15. Speed represented in Time/Distance Graphs Slope SlopeEx. The slope of the line can tell the relative speed of an object. The slope of the line can tell the relative speed of an object. When the slope of the line is steep, the speed is faster than if the slope were flatter. When the slope of the line is steep, the speed is faster than if the slope were flatter.

16. Slope con’t

18. Speed graphs con’t Data Data Table – create a graph from graph from the data listed the data listed in the data in the data table to the table to the right. right. ***Create a line of learning For the graph you created. For the graph you created. Time(s) Distance(m ) 00 15 210 315 415 515 630 745

19. Create a line of learning under your graph. A B C

20. Speed Graphs