Grade 10 Physics: In Motion Mr. Kecman

What do you guys know?

What we will look at Displacement, time, velocity, uniform motion Calculate using formulas and graphs Relationship between velocity, time, acceleration and constant rate History of Motion Inertia in car collisions Forces Newton's laws Momentum and Impulse Friction Braking Distance

Intro Motion: Defined as the process of the movement of an object from one place to another. The study of the motion of objects and the forces that affect their motion is called Mechanics Mechanics is divided up into: Kinematics Dynamics

Kinematics Is the branch of mechanics concerned with motion and its direction. Kinematics answers these questions: Is it moving fast or slow? Is it moving at a constant speed? At rest? What direction is it traveling?

Dynamics Is the branch of mechanics dealing with motion of objects under the action of force. Dynamics answers these questions: Why is the object speeding up or slowing down? How does it turn?

Ways we describe Physics Pictures (diagram) Words (written statement) Numbers (table of values) Graphs (plotted points) Equations (symbols and math)

Diagram

Written Statement 1) Eiko skates to school, a total of 4.5 km. She slows down twice to cross streets, but overall the journey takers 0.62h. What is her average speed during the trip?

Table of Values Position (meters) Time (seconds) 1m 3s 2m 6s 3m 9s 4m

Graph

Equation v = Δd/Δt ->Δd=d2-d1 Δt=t2-t1 a = ->Δv/Δt ->Δv = v2 – v1

Units Distance is the amount of ground covered measured usually in meters. We express it in: Centimeters (cm) Meters (m) Kilometers (km) Millimeters (mm)

Units Time is the duration of an event to take place usually measured in seconds We express time as: Seconds (s) Minutes (min) Hours (hr)

Unit Conversions In this unit you will be working with units! You will have to know how to convert them. Try these: Distance: 1000m = 1km 100cm = 1m 1000mm = 1m Examples: Convert 36m to kms. Convert 1.2m to cm

Unit Conversions Time: Examples: 1 min = 60 s 1 hr = 60 min 1hr = 3600 s Examples: Convert 35 minutes to seconds Convert 4.5 hours to seconds

W.S. Unit conversion worksheets If you finish those try this website on your device! http://www.mathworksheets4kids.com/speed.html Try: Convert m/sec into km/hr: Convert km/hr into m/sec:

Class 2 On the agenda: Distance, position, displacement Scalars, vectors

Distance We know distance is the amount of ground covered measured usually in meters. We can express it in: Centimeters (cm) Meters (m) Kilometers (km) Millimeters (mm)

Distance The symbol for distance is: When distance has changed by moving around an object, we must calculate its change. To do this we use the formula: Δd=df-di Δ stands for “delta” and Δd simply means the change in distance. Δdtotal=d1+d2+d3…..

Distance Ex. Margret drove 15 kilometers to the store, from the store she drove 5 kilometers to the bank, from the bank she drove 9 kilometers to her sisters house. What is the total distance Margret traveled?

Distance Distance is simply the amount of ground covered. (We don’t care how you got there, we just want to know how far you traveled). A real world example would be your car odometer.

Position When we talk about traveling, we have to talk about direction and distances. To understand where you are, you need a reference point. Usually a reference point is your start or point of origin. Direction is needed to determine your position from the point of origin. The clearest way to communicate this is writing North (N), East (E), South (S) and West (W).

Position Your position is the separation and direction from a reference point. Ex. Your position is 152m (W) so verbally we say you are a hundred and fifty two meters west of the reference point. Symbol for position is: ->d Position is stated as positive or negative relative to a zero point. Ex. Board line

Displacement Displacement is defined as the change in position. The symbol is: ->Δd Displacement formula is: ->Δd=d2-d1

Displacement Displacement is expressed as the size of the quantity (including units) and the direction Ex. 33m [W] It represents the straight-line distance from an initial position in a given direction

Displacement Ex. If you travel 20 km [N] and then 5 km [S]: What is your total distance traveled? What is your displacement?

Scalars Vs. Vectors Scalars: Vectors: Quantities that only have a size. Ex. Time (t), distance (m), speed (m/s) Vectors: Quantities that have both a size and direction. The direction is found in a square bracket after the units. (compass points are used as well as positive and negative) Ex. Displacement (m), velocity (m/s) To help distinguish between the two, many scientists place an arrow above vectors.

Drawing Vectors A vector drawing can be expressed as a line segment that represents the size and direction of a vector quantity. Ex. Displacement = 15km [W] Displacement = 25km [S]

Drawing Vectors Ex. Anne takes her dog for a walk. They walk 250 m (W) and then back 215 m (E) before stopping to talk to a neighbor. Draw a vector diagram to find their resultant displacement at this point.

Worksheet 2

Class 3 Go over worksheets Any questions? Explain graphs activity (slope) Moving Man activity

Hand Out We will read over it together. Try out the back after.

Graphs Graphs show quantitative (numerical) information visually. Its more quick and easy to understand than a table of values. Lets you see patterns. Correct for errors. See the slope. What is slope?

What about slope? Slope = rise/run In math, the formula for slope is y=mx+b In physics, the formula for slope is d = v t Lets make a quick small graph to help us see it.

Slope y = mx + b d = v t y = dependent variable m = slope of line x = independent variable b = y-intercept of the line d = v t d = dependent variable v = slope of line t = independent variable

Slope Slope = rise = (y2 – y1) = distance = m run (x2 – x1) time s

Moving Man Grab the worksheet and try the simulation!

Class 4 On the agenda: Speed, instantaneous speed, constant speed, average speed, velocity

Speed Speed is how fast something is moving. To calculate speed, measure the distance covered over a specific time. Formula for speed v = d/t v = speed, d = distance, t = time Verbally we say that the speed (v) is the distance (d) divided by the time (t)

Speed Don’t forget, speed units are? m/s Km/h Speed is also a scalar quantity

Speed Formula

Speed Example Ex. A car travels 220 km in 2.0 hours, what was the car’s speed?

Average Speed Average speed is equal to the total distance divided by the total time for a trip. Equation: vav= Δd/Δt Δd is read as the change in distance (Δd=d2-d1) where d1 is the first distance measured and d2 is the final distance measured Δt is read as the change in time (Δt=t2-t1) where t1 is the initial time and t2 is the final time. t1 is often zero.

Instantaneous speed Instantaneous speed: is the speed at which an object is traveling at a particular instant. It is not affected by its previous speed, or by how long it has been moving. Eg. Speedometer.

Constant Speed If the instant speed of something remains the same over a period of time, then we say that the object is traveling with constant speed. The average speed of an object is the same as its instantaneous speed if that object is traveling at a constant rate.

Velocity Velocity describes how fast something moves in a specific direction. To calculate velocity, measure the change in position over a specific time. Formula for speed v = ->Δd/t ->v = velocity, ->Δd = displacement, t = time Verbally we say that the velocity (->v) is the displacement (->d) divided by the time (t)

Velocity Don’t forget, velocity units are? m/s Km/h Velocity is also a vector quantity

Velocity Examples A train travels at a constant velocity through the countryside and has a displacement of 150 km [E] in a time of 1.7h. What is the velocity of the train? A high school athlete runs 1.00x102 m in 12.20s. What is the velocity in m/s? and km/h?

Speed Velocity W.S.

Class 5 Agenda: Ticker tap lab

A common way of analysing the motion of objects in physics labs is to perform a ticker tape analysis. Kinematics

One tick is equal to 1/60 s or 0.01 s. A ticker tape timer consists of an electrical vibrator which vibrates 60 times per second.  The time interval between two adjacent dots on the ticker-tape is called one tick.  One tick is equal to 1/60 s or 0.01 s. Kinematics

example Find the number of ticks and the time interval between the first dot and the last dot on each of the ticker tapes below. The frequency of the ticker timer is equal to 60Hz. Kinematics

The trail of dots provides a history of the object's motion and is therefore a representation of the object's motion. The distance between dots on a ticker tape represents the object's position change during that time interval. A large distance between dots indicates that the object was moving fast during that time interval. A small distance between dots means the object was moving slow during that time interval. Kinematics

Pattern Explanations The distance between the dots is the same. It shows that the object is moving with constant speed. The distance between the dots is short. It shows that the speed of the object is low. The distance between the dots is far. It shows that the object is moving at a high speed Kinematics

The analysis of a ticker tape diagram will also reveal if the object is moving with a constant velocity or with a changing velocity (accelerating). Kinematics

Pattern Explanations The distance between the dots is increased. It shows that the speed of the object increases. The distance between the dots is decreased. It shows that the speed of the object decreases. Kinematics

Ticker Lab Watch me do a ticker tape run and explain what to do! Then it will be your turn.

Ticker Lab I will put you into groups of 2/3 for this lab now. Everyone is expected to hand in their own individual work. We have 3 ticker timers and cars to play with so we have to cycle on and off because there aren’t enough for every group. In the mean time, other groups should be making up their lab report.

Ticker Lab All you need is your data from your ticker tape which shouldn’t take much time. Your job is to create a lab from scratch. I will give you an outline shell on the board, and you must fill it all in on your own papers and hand it in.

Test You Understanding http://www.physicsclassroom.com/class/1DKin/Lesson-2/Ticker-Tape-Diagrams Try going to this link and answering the questions

Ticker Tape Lab Activity How are you going to show your learning Ticker Tape Lab Activity How are you going to show your learning? Your job . . . • To record the “picture” of uniform motion on ticker tape. • To record the “picture” of acceleration on ticker tape. What materials did you use? Create a list Use proper names for materials Procedure? Written like a recipe or a set of instructions Observations Observations are insightful and accurate, made with appropriate senses and are related to the purpose of the experiment Analysis How will you represent and interpret your data? Conclusion Refer back to the purpose What did you learn?

Class 6 Speed/Velocity on board. Acceleration

Acceleration What is acceleration? It is the increase in the velocity of an object over time To calculate acceleration: Take the ration of the change in velocity to the change in time Formula: a= ->Δv/Δt a: acceleration ->Δv: change in velocity Δt: change in time

Acceleration Formula: Units: Acceleration is a vector. a=->Δv/Δt Expand that to be: a=v2-v1/Δt v2: final velocity v1: initial velocity Units: m/s2 and direction (N,S,E,W,+,-) Acceleration is a vector.

Acceleration Ex. If you speed up on your motorcycle from rest (0m/s) to 9.0m/s in a time of 2.0s, what is your acceleration?

Acceleration This means you will increase your velocity by 4.5m/s every second (0,4.5,9,13.5,18…after 5 seconds) Make a chart!

Acceleration What does acceleration look like on a graph?

Acceleration Ex2. If a car accelerates from 0.0 km/h to 100 km/h in 6.0 s, what is the acceleration of the car?

Acceleration Lets rearrange the formula: a=->Δv/Δt

Acceleration Ex 3. A bus with an initial speed of 12 m/s accelerates at 0.62 m/s2 for 15 seconds. What is the final speed of the bus?

Acceleration W.S.

Class 7 Today we will look at all of the different types of graphs Distance-time Position-time Velocity-time Acceleration-time

Graphs http://physics.info/motion-graphs/problems.shtml Go to the website above and work through the problems. Do Practice problem numbers 2, 3 Try worksheet problems 1-4

Distance-time

Position-time

Velocity-time

Acceleration-time

Class 8 Work Period/Review Class

Class 9 TEST!!

Class 10 Outside?