Motion in One-Direction: Displacement, Velocity, & Acceleration
What is motion? Motion is the change in the position of an object. To describe the motion of an...
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Transcript of What is motion? Motion is the change in the position of an object. To describe the motion of an...
![Page 1: What is motion? Motion is the change in the position of an object. To describe the motion of an object we use terms like: Distance, displacement, speed,](https://reader036.fdocuments.us/reader036/viewer/2022062322/56649e605503460f94b5a283/html5/thumbnails/1.jpg)
![Page 2: What is motion? Motion is the change in the position of an object. To describe the motion of an object we use terms like: Distance, displacement, speed,](https://reader036.fdocuments.us/reader036/viewer/2022062322/56649e605503460f94b5a283/html5/thumbnails/2.jpg)
![Page 3: What is motion? Motion is the change in the position of an object. To describe the motion of an object we use terms like: Distance, displacement, speed,](https://reader036.fdocuments.us/reader036/viewer/2022062322/56649e605503460f94b5a283/html5/thumbnails/3.jpg)
What is motion?
Motion is the change in the position of an object.
To describe the motion of an object we use terms like: Distance, displacement, speed, velocity and
acceleration
![Page 4: What is motion? Motion is the change in the position of an object. To describe the motion of an object we use terms like: Distance, displacement, speed,](https://reader036.fdocuments.us/reader036/viewer/2022062322/56649e605503460f94b5a283/html5/thumbnails/4.jpg)
Distance vs. displacement
• What is distance? Distance is the total path travelled by an object.
- Distance has magnitude (value) only.
• What is displacement? Displacement is the shortest distance between the start point and finish point with direction
- Displacement has magnitude (value) and direction.
- The SI unit for both distance and displacement is meter (m)
![Page 5: What is motion? Motion is the change in the position of an object. To describe the motion of an object we use terms like: Distance, displacement, speed,](https://reader036.fdocuments.us/reader036/viewer/2022062322/56649e605503460f94b5a283/html5/thumbnails/5.jpg)
Example: A car moves from point A to point B then to point C as shown in the opposite diagram. Find the distance and displacement travelled by the car
Answer: Distance = 800 + 300 = 1100 m
Displacement = 1100 m to right
Distance vs. displacement
A B C800 m 300 m
A B C800 m 300 m
![Page 6: What is motion? Motion is the change in the position of an object. To describe the motion of an object we use terms like: Distance, displacement, speed,](https://reader036.fdocuments.us/reader036/viewer/2022062322/56649e605503460f94b5a283/html5/thumbnails/6.jpg)
Example: A horse runs from point A to point C then back to point B as shown in the opposite diagram. Find the distance and displacement travelled by the horse.
Answer: Distance = 800 + 200 = 1000 m
Displacement = 600 m to right
Distance vs. displacement
A B C600 m 200 m
A B C600 m 200 m
![Page 7: What is motion? Motion is the change in the position of an object. To describe the motion of an object we use terms like: Distance, displacement, speed,](https://reader036.fdocuments.us/reader036/viewer/2022062322/56649e605503460f94b5a283/html5/thumbnails/7.jpg)
Example: A man moves from point A to point B then to point C and finally to point D as shown in the opposite diagram. Find the distance and displacement travelled by the man
Answer: Distance = 50 + 30 + 50 = 130 m
Displacement = 30 m to north
Distance vs. displacement
A B
CD
50 m
30 m
A B
CD
50 m
30 m
![Page 8: What is motion? Motion is the change in the position of an object. To describe the motion of an object we use terms like: Distance, displacement, speed,](https://reader036.fdocuments.us/reader036/viewer/2022062322/56649e605503460f94b5a283/html5/thumbnails/8.jpg)
Speed
What is speed? Speed is the travelled distance per unit time.
- speed can be calculated by the formula:
or
- The SI unit of speed is meter per second (m/s).
- Another unit for speed is (km/h).
time
distancespeed
![Page 9: What is motion? Motion is the change in the position of an object. To describe the motion of an object we use terms like: Distance, displacement, speed,](https://reader036.fdocuments.us/reader036/viewer/2022062322/56649e605503460f94b5a283/html5/thumbnails/9.jpg)
Speed
- Formula of speed can be manipulated using:
ds t s
d t where d = s x t or
![Page 10: What is motion? Motion is the change in the position of an object. To describe the motion of an object we use terms like: Distance, displacement, speed,](https://reader036.fdocuments.us/reader036/viewer/2022062322/56649e605503460f94b5a283/html5/thumbnails/10.jpg)
Speed
Example: A horse runs a distance of 1200 m in 40 s with constant speed. Calculate the speed of the horse.
Answer: Given: d = 1200 m t = 40 s s = ?
t
d s
401200
m/s 30
![Page 11: What is motion? Motion is the change in the position of an object. To describe the motion of an object we use terms like: Distance, displacement, speed,](https://reader036.fdocuments.us/reader036/viewer/2022062322/56649e605503460f94b5a283/html5/thumbnails/11.jpg)
Speed
Example: A car travels with a constant speed of 20 m/s. How much distance the car will travel in 8 s?
Answer: Given: s = 20 m/s t = 8 s d = ?
tsd 8 x 20 m 160
![Page 12: What is motion? Motion is the change in the position of an object. To describe the motion of an object we use terms like: Distance, displacement, speed,](https://reader036.fdocuments.us/reader036/viewer/2022062322/56649e605503460f94b5a283/html5/thumbnails/12.jpg)
Speed
Example: How long will it take a man running with a constant speed of 8 m/s to travel a distance of 400 m?
Answer: Given: s = 8 m/s d = 400 m t = ?
s
d t
8400
s 50
![Page 13: What is motion? Motion is the change in the position of an object. To describe the motion of an object we use terms like: Distance, displacement, speed,](https://reader036.fdocuments.us/reader036/viewer/2022062322/56649e605503460f94b5a283/html5/thumbnails/13.jpg)
Speed
Example: what does it mean to say that the speed of plane is 80 m/s?
Answer: It means that the plane flies a distance of 80 m every
second.
![Page 14: What is motion? Motion is the change in the position of an object. To describe the motion of an object we use terms like: Distance, displacement, speed,](https://reader036.fdocuments.us/reader036/viewer/2022062322/56649e605503460f94b5a283/html5/thumbnails/14.jpg)
Distance-time graph• Speed could be represented by graph called distance-
time graph.
• In distance-time graph: distance is represented on the vertical axis and time is represented on horizontal axis
Time (s)D
ista
nce
(m)
![Page 15: What is motion? Motion is the change in the position of an object. To describe the motion of an object we use terms like: Distance, displacement, speed,](https://reader036.fdocuments.us/reader036/viewer/2022062322/56649e605503460f94b5a283/html5/thumbnails/15.jpg)
Distance-time graph• Distance-time graph could have different
shapes, two of them are:
Time (s)
Dis
tanc
e (m
)
Time (s)D
ista
nce
(m)
![Page 16: What is motion? Motion is the change in the position of an object. To describe the motion of an object we use terms like: Distance, displacement, speed,](https://reader036.fdocuments.us/reader036/viewer/2022062322/56649e605503460f94b5a283/html5/thumbnails/16.jpg)
Distance-time graph• When the distance-time graph has the opposite shape then it means that the object is: moving with constant speed (speed is not changing)
• The slope (steepness) of the of the line equals the speed.
• The steeper the line (more slope) the greater is the speed
Time (s)
Dis
tanc
e (m
)
![Page 17: What is motion? Motion is the change in the position of an object. To describe the motion of an object we use terms like: Distance, displacement, speed,](https://reader036.fdocuments.us/reader036/viewer/2022062322/56649e605503460f94b5a283/html5/thumbnails/17.jpg)
Distance-time graphExample: The opposite graph represents the motion of two objects A and B. Which of the two objects have more speed. Explain why.
Answer: Object A has more speed because the slope of its line
is steeper (has more slope).
Time (s)
Dis
tanc
e (m
)
A
B
![Page 18: What is motion? Motion is the change in the position of an object. To describe the motion of an object we use terms like: Distance, displacement, speed,](https://reader036.fdocuments.us/reader036/viewer/2022062322/56649e605503460f94b5a283/html5/thumbnails/18.jpg)
Distance-time graph• When the distance-time graph has the opposite shape then it means that the object is: at rest, not moving, speed = 0 or slope = 0
Time (s)
Dis
tanc
e (m
)
![Page 19: What is motion? Motion is the change in the position of an object. To describe the motion of an object we use terms like: Distance, displacement, speed,](https://reader036.fdocuments.us/reader036/viewer/2022062322/56649e605503460f94b5a283/html5/thumbnails/19.jpg)
Average speed and instantaneous speed• When an object is moving with changing speed (speed
is not constant) then its motion is described by: 1- Average speed. 2- Instantaneous speed.
Average speed is the total distance travelled divided by the total time of travel.
Instantaneous speed is the speed at a given moment (point of time)
In a moving car instantaneous speed could be determined from the speedometer
![Page 20: What is motion? Motion is the change in the position of an object. To describe the motion of an object we use terms like: Distance, displacement, speed,](https://reader036.fdocuments.us/reader036/viewer/2022062322/56649e605503460f94b5a283/html5/thumbnails/20.jpg)
Velocity
Velocity is the speed of an object and its direction.
Speed has magnitude (value) only.
Velocity has magnitude (value) and direction.
5 m/s
5 m/s
5 m/s
5 m/s
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5 m/s
5 m/s
5 m/s
5 m/s