chapter resources ●a motion diagram shows the position of an object at successive times. ●in the...
TRANSCRIPT
Chapter ResourcesChapter Resources
● A motion diagram shows the position of an object at successive times.
● In the particle model, the object in the motion diagram is replaced by a series of single points.
Picturing Motion
Section
2.1Section
2.1
Chapter ResourcesChapter Resources
● You can define any coordinate system you wish in describing motion, but some are more useful than others.
● A time interval is the difference between two times.
Where and When?
Section
2.2Section
2.2
Chapter ResourcesChapter Resources
● A vector drawn from the origin of the coordinate system to the object indicates the object’s position.
● Change in position is displacement, which has both magnitude and direction.
Where and When?
Section
2.2Section
2.2
Chapter ResourcesChapter Resources
● The length of the displacement vector represents how far the object was displaced, and the vector points in the direction of the displacement.
Where and When?
Section
2.2Section
2.2
Chapter ResourcesChapter Resources
● Position-time graphs can be used to find the velocity and position of an object, as well as where and when two objects meet.
● Any motion can be described using words, motion diagrams, data tables, and graphs.
Position-Time Graphs
Section
2.2Section
2.2
Chapter ResourcesChapter Resources
● The slope of an object’s position-time graph is the average velocity of the object’s motion.
How Fast
Section
2.2Section
2.2
● The average speed is the absolute value of the average velocity.
Chapter ResourcesChapter Resources
● An object’s velocity is how fast it is moving and in what direction it is moving.
How Fast
Section
2.2Section
2.2
● An object’s initial position, di, its constant average velocity, , its position d, and the time, t, since the object was at its initial position, are related by a simple equation.
Chapter ResourcesChapter ResourcesChapter
2Chapter
2
If an object in the motion diagram is replaced by a series of single points, to which type of motion diagram are you referring?
A. Motion diagram
B. Particle model
C. Coordinate system
D. Position-time graph
Chapter Assessment Questions
Chapter ResourcesChapter ResourcesChapter
2Chapter
2
Reason: A particle model is a simplified version of a motion diagram in which the object in motion is replaced by a series of single points.
Chapter Assessment Questions
Chapter ResourcesChapter ResourcesChapter
2Chapter
2
Refer to the figure and calculate the distance between the two signals?
Chapter Assessment Questions
A. 3 m
B. 8 m
C. 5 m
D. 5 cm
Chapter ResourcesChapter ResourcesChapter
2Chapter
2
Reason: Distance d = df – di Here, df = 8 m and di = 3 mTherefore, d = 8 m – 3 m = 5 m
Chapter Assessment Questions
Chapter ResourcesChapter ResourcesChapter
2Chapter
2
From the adjacent position-time graph determine the distance covered by the competitor between 5 s and 10 s?
Chapter Assessment Questions
Chapter ResourcesChapter ResourcesChapter
2Chapter
2
Answer: The distance covered by the competitor between 5 s and 10 s is d = 20 m – 10 m = 10 m.
Chapter Assessment Questions
Chapter ResourcesChapter ResourcesChapter
2Chapter
2
A car starting from rest moves with an average speed of 6 m/s. Use the equation of motion for average velocity to calculate the distance the car traveled in 1 minute.
Chapter Assessment Questions
A. 6 m
B. 10 m
C. 60 m
D. 360 m
Chapter ResourcesChapter ResourcesChapter
2Chapter
2
Chapter Assessment Questions
Reason: The equation of motion for average velocity is d = vt + di where d is the object’s position at time t of the object moving with average velocity v, and di is the initial position of the object. In this case di = 0, v = 6 m/s and t = 1 min = 60 s. Therefore d = (6 m/s)(60 s) + 0 m = 360 m.
Chapter ResourcesChapter ResourcesChapter
2Chapter
2
The position-time graph at right shows three ships moving in a river. Determine which ship has greater average velocity?
Chapter Assessment Questions
A. Ship A
B. Ship B
C. Ship C
D. Both ship B and C
Chapter ResourcesChapter ResourcesChapter
2Chapter
2
Reason: The slope of A is steeper than the slopes of B and C. A steeper slope indicates a greater change in displacement during each time interval, i.e. greater average velocity.
Chapter Assessment Questions
