Motion Chapter 10

What do these pictures have in common?

Describe how your motion has changed as you moved from the school’s entrance into the classroom.

Example: Rashaad traveled 20 meters. Write a sentence that uses the word METER to show its scientific meaning. Example: Rashaad traveled 20 meters.

Motion All matter is constantly in motion. Motion involves a change in position.

Position The car is to the right of the tree. The tree does not move. The car must have moved from one place to another. Therefore, here the tree is considered as the frame of reference. frame of reference – coordinate system used to define motion. An object changes position if it moves in relationship to the frame of reference or reference point.

Position reference point– zero location in a frame of reference. The car is to the right of the tree. The tree does not move. The car must have moved from one place to another. Therefore, here the tree is considered as the frame of reference. frame of reference – coordinate system used to define motion. reference point– zero location in a frame of reference. position – separation between an object and the reference point. It describes where something is in relation to the reference point.

Quantities

Categorize each quantity as being either a vector or a scalar 5m 30m/sec. east 5mi. North 20 degree Celsius 256 bytes 4000 Calories

PART ONE DISTANCE & DISPLACEMENT

Distance a measure of the interval between two locations measured along the actual path connecting them

Displacement a vector measure of the interval between two locations measured along the shortest path connecting them

Distance vs. Displacement

Vocabulary 1. Motion 2. Position 3. Frame of reference 4. Reference point 5. Scalar Quantities 6. Vector Quantities 7. Distance 8. Displacement

PART TWO SPEED & VELOCITY

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Types of Speed Average speed is the total distance traveled divided by total time taken. An object’s speed at a particular moment in time is called instantaneous speed. Constant speed occurs when an object travels at a steady rate with the same instantaneous speed for some period of time.

Vocabulary 9. speed 10. meter 11. seconds 12. Average Speed 13. Instantaneous speed 14. Constant Speed 15. velocity

Summary The steeper the graph, the faster the motion. A horizontal line means the object is not changing its position - it is not moving, it is at rest. A downward sloping line means the object is returning to the start.

Can you spot the difference? The only way you can tell the difference is by reading the labels on the axes. HINT: Always read the labels on the axes! Failure to do so can mean you completely mis-interpret what it shows.

Velocity- Time Graphs Speed-Time graphs are also called Velocity-Time graphs. A graph is used to demonstrate the relationship between speed and time.

Velocity- Time Graphs Just like distance/time graphs, there are some basic graphs to learn. This is just a horizontal line: Don't be tempted to think this means it's stationary! This is speed/time, and the speed is both positive and constant. This shows a constant speed.

The speed is increasing, so the object must be accelerating.

The speed is decreasing, so the object must be decelerating. Note that this shape of distance-time graph would mean steady speed back to where you came from. Totally different!

Both the yellow and blue line show increasing speed. They both reach the same top speed, but the blue one takes longer.

Summary A speed - time graph shows us how the speed of a moving object changes with time. The steeper the graph, the greater the acceleration. A horizontal line means the object is moving at a constant speed. A downward sloping line means the object is slowing down.

Vocabulary 16. Distance-Time Graph 17. Velocity- Time Graph