Presentation is loading. Please wait.

Presentation is loading. Please wait.

Average Velocity PowerPoint 8.2.

Published byViolet Craig Modified over 6 years ago

Similar presentations

Presentation on theme: "Average Velocity PowerPoint 8.2."β€” Presentation transcript:

1 Average Velocity PowerPoint 8.2

2 Speed versus Velocity scalar quantity Magnitude but no direction
Speed, 𝑣, is the distance travelled during a given time interval divided by that time interval, 𝑣= 𝑑 Δ𝑑 = 𝑑 𝑓 βˆ’ 𝑑 𝑖 𝑑 𝑓 βˆ’ 𝑑 𝑖 . vector quantity Magnitude and direction Velocity, 𝑣 , is the displacement during a given time interval divided by that time interval, 𝑣 = Ξ” 𝑑 Δ𝑑 = 𝑑 𝑓 βˆ’ 𝑑 𝑖 𝑑 𝑓 βˆ’ 𝑑 𝑖 . The SI units for both 𝑣 and 𝑣 is m/s, but km/h is also utilized.

3 How would you describe the speed and velocity o each jogger?
The female’s 𝑑 changes more than the male’s in the same Δ𝑑. The female has greater 𝑣 and greater velocity 𝑣 than the male as is shown by the steeper positive slope.

4 Slope of a Position-Time Graph
Female Male π‘†π‘™π‘œπ‘π‘’= π‘Ÿπ‘–π‘ π‘’ π‘Ÿπ‘’π‘› π‘†π‘™π‘œπ‘π‘’= π‘Ÿπ‘–π‘ π‘’ π‘Ÿπ‘’π‘› π‘π‘œπ‘ π‘–π‘‘π‘–π‘œπ‘›, 𝑑 (m, forward) = Ξ” 𝑑 Δ𝑑 = Ξ” 𝑑 Δ𝑑 = 𝑣 = 𝑣 = 𝑑 𝑓 βˆ’ 𝑑 𝑖 𝑑 𝑓 βˆ’ 𝑑 𝑖 = 𝑑 𝑓 βˆ’ 𝑑 𝑖 𝑑 𝑓 βˆ’ 𝑑 𝑖 Time, t (seconds) The slope of a an object’s position-time graph is its average velocity, 𝑣 π‘Žπ‘£ = 20 π‘š βˆ’12 π‘š 5 𝑠 βˆ’3 𝑠 = 10 π‘š βˆ’4 π‘š 5 𝑠 βˆ’2 𝑠 = 8 π‘š 2 𝑠 = 6 π‘š 3 𝑠 The steeper the slope, the greater the velocity, 𝑣 π‘Žπ‘£ =4 π‘š 𝑠 π‘“π‘œπ‘Ÿπ‘€π‘Žπ‘Ÿπ‘‘ =2 π‘š 𝑠 π‘“π‘œπ‘Ÿπ‘€π‘Žπ‘Ÿπ‘‘

5 More About Slopes Positive slope, 𝑣 π‘Žπ‘£ in the positive direction, 𝑣 π‘Žπ‘£ > 0. Zero slope, stationary, 𝑣 π‘Žπ‘£ = 0. Negative slope, 𝑣 π‘Žπ‘£ in the negative direction, 𝑣 π‘Žπ‘£ < 0.

6 What is the average velocity for the following time intervals?
𝑣 π‘Žπ‘£ = 8 π‘š βˆ’0 π‘š 4 𝑠 βˆ’0 𝑠 =2 π‘š 𝑠 0 s to 4 s 𝑣 π‘Žπ‘£ = 8 π‘š βˆ’8 π‘š 7 𝑠 βˆ’4 𝑠 =0 π‘š 𝑠 4 s to 7 s 𝑣 π‘Žπ‘£ = 14 π‘š βˆ’8 π‘š 13 𝑠 βˆ’7 𝑠 = π‘š 𝑠 7 s to 13 s 𝑣 π‘Žπ‘£ = 0 π‘š βˆ’14 π‘š 13 𝑠 βˆ’15 𝑠 =βˆ’7 π‘š 𝑠 13 s to 15 s

7 Determining 𝑣 π‘Žπ‘£ with a Line of Best-Fit
In reality, very few things move in uniform motion. With a line that passes through or close to each point, the average velocity can be calculated. Position, m π‘†π‘™π‘œπ‘π‘’= π‘Ÿπ‘–π‘ π‘’ π‘Ÿπ‘’π‘› = 40 π‘š βˆ’10 π‘š 40 𝑠 βˆ’10 𝑠 =1 π‘š/𝑠 Time, s

8 Practice with Graphing and Best-Fit Lines
With the data below, construct a position-time graph and plot the data points. Draw a best-fit line. Calculate the slope of the best-fit line. Position (m [E]) 7 15 20 26 35 42 49 56 Time (s) 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 70 60 50 π‘†π‘™π‘œπ‘π‘’= π‘Ÿπ‘–π‘ π‘’ π‘Ÿπ‘’π‘› = 𝑦 2 βˆ’ 𝑦 1 π‘₯ 2 βˆ’ π‘₯ 1 40 Position, m 30 20 = 46 π‘š βˆ’15 π‘š 13 𝑠 βˆ’4 𝑠 10 2 4 6 8 10 12 14 16 =3.4 π‘š/𝑠 Time, s

9 Calculating Time Intervals and Displacement
𝑣 π‘Žπ‘£ = Ξ” 𝑑 Δ𝑑 Δ𝑑= Ξ” 𝑑 𝑣 π‘Žπ‘£ 𝑣 π‘Žπ‘£ ·Δ𝑑= Ξ” 𝑑 𝑣 π‘Žπ‘£ Β· Δ𝑑= Ξ” 𝑑 Δ𝑑 Β· Δ𝑑 Δ𝑑·1= Ξ” 𝑑 Δ𝑑· 𝑣 π‘Žπ‘£ ·Δ𝑑 𝑣 π‘Žπ‘£ 𝑣 π‘Žπ‘£ = Ξ” 𝑑 Δ𝑑· 𝑣 π‘Žπ‘£ Ex. Travelling at 2.5 m/s, how long would it take someone to walk 150 m? Ex. If a baseball is thrown at 25 m/a toward home plate, what would be the ball’s displacement after 0.65 s? Δ𝑑= Ξ” 𝑑 𝑣 π‘Žπ‘£ = 150 π‘š 2.5 π‘š/𝑠 =60 𝑠 Ξ” 𝑑 = 𝑣 π‘Žπ‘£ ·Δ𝑑 = (25 m/s)(0.65 s) = m

10 Converting Units But how? 8= 8Β·4 4 90 km/h = ? m/s
Ensure all units are the same before doing calculations or comparisons! But how? 8= 8Β·4 4 90 km/h = ? m/s Units can be treated like factors above and below the division. 90 π‘˜π‘š π‘š 1 π‘˜π‘š = π‘š π‘š 3600 𝑠 =25 π‘š/𝑠 1 β„Žπ‘œπ‘’π‘Ÿ 60 π‘šπ‘–π‘›π‘’π‘‘π‘’π‘  1 β„Žπ‘œπ‘’π‘Ÿ π‘ π‘’π‘π‘œπ‘›π‘‘π‘  1 π‘šπ‘–π‘›π‘’π‘‘π‘’ =3600 𝑠 90 π‘˜π‘š 1 β„Žπ‘œπ‘’π‘Ÿ 1000 π‘š 1 π‘˜π‘š 1 β„Žπ‘œπ‘’π‘Ÿ 60 π‘šπ‘–π‘›π‘’π‘‘π‘’π‘  1 π‘šπ‘–π‘›π‘’π‘‘π‘’ 60 π‘ π‘’π‘π‘œπ‘›π‘‘π‘  = 25 π‘š 1 𝑠 =25 π‘š/𝑠

11 Provincial Exam Question
If a car moves from +7 m to -21 m in 2 s, what is the car’s average velocity? A. -14 m/s B. -7 m/s C. +7 m/s D. +14 m/s Answer A. 𝑣 π‘Žπ‘£ = Ξ” 𝑑 Δ𝑑 = 𝑑 𝑓 βˆ’ 𝑑 𝑖 Δ𝑑 = βˆ’21 π‘š βˆ’(7 π‘š) (2 𝑠) = βˆ’28 π‘š 2 𝑠 =βˆ’14 π‘š/𝑠

12 Provincial Exam Question
A family on vacation drove 200 km in two hours and then travelled only 40 km during the next hour due to a construction zone. What was the family’s average velocity during the trip? A. 40 km/h B. 70 km/h C. 80 km/h D km/h Answer C. 𝑣 π‘Žπ‘£ 1 = Ξ” 𝑑 Δ𝑑 = 200 π‘˜π‘š 2 β„Ž =100 π‘˜π‘š β„Ž 𝑣 π‘Žπ‘£ 2 = Ξ” 𝑑 Δ𝑑 = 40 π‘˜π‘š 1 β„Ž =40 π‘˜π‘š/β„Ž 𝑣 π‘Žπ‘£ = 100 π‘˜π‘š β„Ž +100 π‘˜π‘š β„Ž +40 π‘˜π‘š β„Ž 3 =80 π‘˜π‘š/β„Ž

13 Provincial Exam Question
How far did the girl move during 3s? A. 3.0 m B. 4.5 m C. 6.0 m D. 9.0 m 10 9 8 Answer B. Plot the data points. Draw a best-fit line. At what position is the girl at t = 3 s? 4.5m Time, s Position, m 2 3.0 4 6.0 6 9.0 7 6 Position, m 5 4 3 2 1 1 2 3 4 5 6 7 Time, s

14 Provincial Exam Question
Which of the following conditions is represented by the graph? A. uniform motion B. zero acceleration C. constant velocity D. increasing velocity Answer D. Because the slope of a position-time graph is the velocity, an increasingly steep slope indicates that the velocity is increasing.

15 Summary Speed, 𝑣, is a scalar. Velocity, 𝑣 , is a vector.
𝑣 π‘Žπ‘£ = Ξ” 𝑑 Δ𝑑 Average velocity, 𝑣 π‘Žπ‘£ , displacement, Ξ” 𝑑 , and time interval, Δ𝑑, can be calculated from the following formulae Ξ” 𝑑 = 𝑣 π‘Žπ‘£ ·Δ𝑑 The slope of a position-time graph represent an object’s 𝑣 π‘Žπ‘£ . Δ𝑑= Ξ” 𝑑 𝑣 π‘Žπ‘£ Unit conversion, 90 π‘˜π‘š 1 β„Žπ‘œπ‘’π‘Ÿ 1000 π‘š 1 π‘˜π‘š 1 β„Žπ‘œπ‘’π‘Ÿ 60 π‘šπ‘–π‘›π‘’π‘‘π‘’π‘  1 π‘šπ‘–π‘›π‘’π‘‘π‘’ 60 π‘ π‘’π‘π‘œπ‘›π‘‘π‘  = 25 π‘š 1 𝑠 =25 π‘š/𝑠

Download ppt "Average Velocity PowerPoint 8.2."

Similar presentations

Motion: 8.2 THURSDAY APRIL 17 th Cheetah clip (c) McGraw Hill Ryerson 2007.

Motion: 8.2 THURSDAY APRIL 17 th Cheetah clip (c) McGraw Hill Ryerson 2007.
Average Velocity.

Average Velocity.
8.1 The Language of Motion Some common words used to describe motion include: Distance Time Speed Position How would you describe the motion of the soccer.

8.1 The Language of Motion Some common words used to describe motion include: Distance Time Speed Position How would you describe the motion of the soccer.
8.1 The language of motion.

8.1 The language of motion.
(c) McGraw Hill Ryerson 2007 8.2 Average Velocity Speed ( ) is the distance an object travels during a given time interval divided by the time interval.

(c) McGraw Hill Ryerson Average Velocity Speed ( ) is the distance an object travels during a given time interval divided by the time interval.
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,

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,
Speed ( ) is the distance an object travels divided by the time to travel that distance. In other words –Speed is a scalar quantity (no direction). These.

Speed ( ) is the distance an object travels divided by the time to travel that distance. In other words –Speed is a scalar quantity (no direction). These.
UNIT #3 – CHAPTER #8.2 – AVERAGE VELOCITY. Objectives ο‚ž Be able to calculate average velocity, displacement, and time interval for an object in uniform.

UNIT #3 – CHAPTER #8.2 – AVERAGE VELOCITY. Objectives ο‚ž Be able to calculate average velocity, displacement, and time interval for an object in uniform.
Linear Motion Review. 1.Speed is a ____ quantity. A.) vector B.) scalar C.) additive D.) subtractive.

Linear Motion Review. 1.Speed is a ____ quantity. A.) vector B.) scalar C.) additive D.) subtractive.
Distance and Displacement Speed and Velocity GraphingAcceleration 10 20 30 40 50 60 70 80 90 Final Jeopardy Physics Jeopardy.

Distance and Displacement Speed and Velocity GraphingAcceleration Final Jeopardy Physics Jeopardy.
MOTION IN ONE DIMENSION AVERAGE / INSTANTANEOUS SPEED POSITION AND DISPLACEMENT AVERAGE / INSTANTANEOUS VELOCITY AVERAGE / INSTANTANEOUS ACCELERATION.

MOTION IN ONE DIMENSION AVERAGE / INSTANTANEOUS SPEED POSITION AND DISPLACEMENT AVERAGE / INSTANTANEOUS VELOCITY AVERAGE / INSTANTANEOUS ACCELERATION.
Motion Is it moving? How is it measured?. Describing Motion MOTION When an object changes position relative to a reference point we call it MOTION! Reference.

Motion Is it moving? How is it measured?. Describing Motion MOTION When an object changes position relative to a reference point we call it MOTION! Reference.
Speed ( ) is the distance an object travels divided by the time to travel that distance. In other words –Speed is a scalar quantity (no direction). These.

Speed ( ) is the distance an object travels divided by the time to travel that distance. In other words –Speed is a scalar quantity (no direction). These.
Physics Unit 2 1-D and 2-D Motion Topics: 4 What is Linear Motion? 4 Vector vs. Scalar Quantities 4 Distance vs. Displacement (Comparison) 4 Speed vs.

Physics Unit 2 1-D and 2-D Motion Topics: 4 What is Linear Motion? 4 Vector vs. Scalar Quantities 4 Distance vs. Displacement (Comparison) 4 Speed vs.
Uniform Motion.

Uniform Motion.
Velocity is a vector quantity therefore must include direction.

Velocity is a vector quantity therefore must include direction.
Direction Makes a Difference Quantities that describe magnitude but DO NOT include direction are called scalar quantities or just scalars. (distance, speed,

Direction Makes a Difference Quantities that describe magnitude but DO NOT include direction are called scalar quantities or just scalars. (distance, speed,
Speed ( ) is the distance an object travels divided by the time to travel that distance. In other words –Speed is a scalar quantity (no direction). These.

Speed ( ) is the distance an object travels divided by the time to travel that distance. In other words –Speed is a scalar quantity (no direction). These.
8.1 The Language of Motion Some common words used to describe motion include: Some common words used to describe motion include: –Distance –Time –Speed.

8.1 The Language of Motion Some common words used to describe motion include: Some common words used to describe motion include: –Distance –Time –Speed.
Resolve the vector into x & y components 40.0 m/s at 45 o SoW.

Resolve the vector into x & y components 40.0 m/s at 45 o SoW.

Similar presentations

Ads by Google