Unit 7

Unit 7The Track & Field Championship

Essential Questions

What is the relationship between speed, distance, and time, and how are they calculated?

How can we use trends from track and field competitions to make predictions for future competition results?

Are average speed and speed the same at all points in a race?

How can we use a graph to analyze a runner’s speed in a race?

How does our stride length relate to wavelength, and how can we use this data to calculate the frequency of a runner?

What is the difference between motion and landing position of objects dropped straight down to those with projectile motion?

How does the concept of energy conservation relate to the pole vault?

Chapter Challenge (pp. 140-141)

TASOK is going to send a track and field team to the Penn Relays

You need to write a physics manual to train the TASOK team and help them improve their performance for 3 different track & field events (must include 1 field and 1 track event) which includes the following:

Include a description of the physics principles related to the eventsProvide specific techniques to improve performance (diagrams recommended)Help students compare themselves with their competitors (i.e. are there different techniques for your events?)

Due Date: April 12

Day 1: Running the Race

Learning Objectives:Measure distance in meters along a straight lineUse a stopwatch to measure the amount of time for a person to travel a measured distanceUse measurements of distance and time to calculate the average speed of a running personCompare the average speeds of a running person during segments of a runCompare the average speeds of different persons running along the same pathInfer factors which affect the average speed of a running person

Starter

Starter (cont’d)Very few people can run the 100m in under 10s (Usain Bolt ran it in 9.63s at this past summer’s Olympic Games)

How can you measure a runner’s speed?

Does running twice as far take twice as much time? Explain.

What time do you think Usain Bolt ran (& won) the 200m finals in at this past Olympics?

Time: 15 minutes

Activity 1You will be put into groups of 5 people

Choose 1 person in the group who will run 20m

The other 4 people will be timers

Mark out a 20m “track” with markers every 5m (ie. At 0m, 5m, 10m, 15m, and 20m)

The timers will stand at all the positions (except 0m) and record the time it takes for the runner to start to get to their position

How will you calculate the time taken to run the 5m interval you need to time?

The person at the 5m mark will be the starter

Run 3 trials, giving the runner a couple of minutes in between to rest. This is when you can record your data

Time: 30 minutes

Data TableDistance 0-5m 5-10m 10-15m 15-20m

Trial #1 Time (s)Speed (m/s)

Trial #2 Time (s)Speed (m/s)

Trial #3 Time (s)Speed (m/s)

Average speed (m/s)

Activity 2Calculate the speed at the different intervals and complete your table

How do you calculate the different times? You will need to work together and have everyone’s data to calculate these.

What was the runner’s average speed for the 4 intervals?

Does running twice as far take twice as much time?

What is the runner’s average speed for the entire 20m? How does this compare to the 4 intervals?

Which interval did the runner have the greatest speed? How does this compare to other group’s data?

Time: 15 minutes

Activity 3Graph the data you collected, using the average time for each of the four intervals

What type of graph will you use?

What information goes on the x-axis? The y-axis?

Give your graph an appropriate title

Time: 10 minutes

Closing & Homework

Create a distance, speed, time triangle that can be used to calculate for an unknown.

Read “For You to Read” pg. 145

Physics to Go, pg. 146 #1a, 2, 4, 6

Reminder: All corrections and outstanding work due this Friday!

Day 2: Analysis of Trends

Learning Objectives:Sketch a best fit curve or trend line on a graph on which points have been plottedExtrapolate graphs to predict trends beyond available dataCreate graphs of data presented in tabular formCalculate the average speed of a runner given distance and timeCalculate the time required for a runner to travel a specified distance given the runner’s average speedInterpret information presented in graphical form

StarterCurrent trends indicate that women will start outrunning men in 65 years

Watch the following videos. One is from 1928, the other is from 2012.

Is it useful to compare track records over many years of time?

Can future track records be predicted based on past performances?

What are some differences that you notice between the races from the two time periods?

Time: 20 minutes

Activity 1Look at the graph “Speed vs. Year: Men’s Olympic 400m Dash”

What is this graph showing?

Sketch a curved line or straight line through the data points

What is the trend that you observe happening in the speed for the 400m over the past 100 years?

Guess what the line would look like until 2020. According to your extrapolation, what will the speed of the winner of the 2020 Olympics be?

In 1980, the speed of the winner is ~9.0m/s. How fast did the winner do the 400m run in (assume 9.0m/s)?

Time: 20 minutes

Activity 2Look at the graph “Speed vs. Distance: Men and Women, Penn Relays”

What does this graph show?

Sketch the shapes of the two graphs that are shown

What do you notice about the trends of the average speed for men and women as the distance of the races get longer?

Extrapolate to predict the record speed for the 10,000m for men and women

Time: 20 minutes

Activity 3Your plan to help your school’s track team at the Penn Relays will only be as good as your knowledge of current performances in T&F.

Research the top times/distances for under 18 boys and girls(high school students) in the following events (use meters for the field events). Some Canadian sites to help you include OTFA and OFSAA.

High Jump100m400m hurdles1500mTriple Jump

Time: 20 minutes

Closing & Homework

Does knowing past performances help determine future performances? Why or why not?

Physics to Go, pg. 150 #2, 3, 4,5

Day 3: Who Wins the Race?

Learning Objectives:Measure short time intervals in arbitrary unitsMeasure distances to the nearest mmUse a record of an object’s position vs. time to calculate the object’s average speed during designated position and time intervalsMeasure and describe changes in an object’s speedRelate changes in the speed of an object traveling on a complex sloped track to the shape of the track

StarterThe average jogging pace for a human is 9-12 km/h. The average running pace for a human is (top athlete) 36 km/h.

How fast does an average car travel?

How do you determine who wins a race?The runner with the highest finishing speed?The runner with the highest average speed?The runner with the greatest top speed?

Time: 15 minutes

Starter

Activity 1Move to your lab groups

Design an experiment that determines a cart’s average speed

You will test the cart’s speed on a flat surface and three inclines

Sections to include are:Aim/ObjectiveHypothesisMaterialsProcedureDataAnalysis (after experiment is complete)

Time: 20 minutes

Activity 2Carry out your investigation after you have your plan okayed by me

Type up your plan and results

Due: Friday, March 22

Time: 30 minutes

Closing & Homework

How do you determine the average speed of an object?

On which track produced the top speed for your cart?

Physics to go, pg. 155 #3, 4, 5, 6

Day 4: Understanding the Sprint (60

min)Learning Objectives:Calculate the average speed of a runner given distance and timeProduce a histogram showing the average speeds of a runner during segments of a race; analyze changes in a runner’s speedProduce a graph of distance vs. time from split time data for a runnerEstimate the slope of a distance vs. time graph at specified timesRecognize that the slope of a distance vs. time graph at a particular time represents the speed at that time

Starter

Starter

StarterAfter watching the videos for the 100m (Carl Lewis, 1991) and the long jump (Mike Powell, 1991) discuss the following questions:

How long does it take to get up to maximum speed?Does it differ depending on the event you are competing in? Why?When does a sprinter want to be at their maximum speed? How about a long jumper?

Time: 15 minutes

Activity 1Work through steps 1-5 on pp. 156-158

Graph paper is available for you to use

When you finish, you can do research for your chapter challenge

Time: 45 minutes

Homework Physics to go, pg. 159 #2, 3, 5

Day 5: Acceleration

Learning Objectives:Understand the definition of accelerationUnderstand meters per second per second as the unit of accelerationDistinguish between acceleration and deceleration

StarterAccelerating out of the starting block is important if a runner is going to win a race

If all runners in a race have equal top speeds and none “fade” at the end of the race, what determines who wins?

How is response time a factor in determining who wins the race?

What do you think blocks do, and what do you think the correct technique is for starting in them?

Time: 15 minutes

Starter

Activity 1In your lab groups, construct an accelerometer like the picture below

Activity 2Work through the “For you to do”

Choose someone who doesn’t normally record to be the recorder

Choose 2 people to walk forwards and backwards to compare results and make sure that your results are accurate

Time: 45 minutes

Closing & Homework

You can use this time to research your events for the chapter challenge

I am going to come around and ask your groups and what events you are doing

Read “Physics Talk”, pg. 162 and “For you to Read”, pg. 163

Physics to Go, pg. 165 #1, 2, 3, 6, Choose 3 from 8, 9, 10, 12, 13, 14, 15, or 16

Day 6: Measurement

Learning Objectives:Calibrate the length of a strideMeasure a length by pacing and with a meter stickIdentify sources of error in measurementEvaluate estimates of measurements as reasonable or unreasonableMeasure various objects and calculate the error in each measurement

Starter

StarterIn about 200 BC, Eratosthenes calculated the circumference of Earth. He used shadows cast by the sun in two cities and a measurement of the distance between the two cities. The distance between the cities was found by pacing.

Two people measure the length of the same object. One reports a length of 3m, the other reports a length of 10m. Has one of them goofed? Why do you think?

What if the measurements were 3m and 3.1m?

How does this play a factor in measuring the distances jumped or thrown in track and field events?

Is there room for error in these events? How so?

Time: 15 minutes

Activity 1Move to your new lab groups

Work through steps 1-8 on pp.167-169

Choose 1 person to record, one person to walk, and one (or two) person (people) to measure

Hand in your answers/observations when complete

Time: 40 minutes

Activity 2You may use this time to work on your chapter challenge

This is your last chance before break to ask me questions about form, technique, etc.

Closing & Homework

For you to read, pg. 169

Physics to go, pg. 170 #1, 3, 4, 7

Day 7: Increasing Top Speed

Learning ObjectivesCalculate the average speed of a runner given distance and timeMeasure the frequency of strides of a running personMeasure the length of strides of a running personRecognize that either the equation (speed = distance/time) or the equation (speed = stride frequency x stride length) may be used to calculate a runner’s speed with equivalent resultsInfer ways in which stride length and stride frequency can be adjusted by a runner to increase speed

StarterA cheetah can reach a top speed of 100km/h (30m/s)

What is the top speed a runner can reach?

Watch the video of the cheetah running

What are some differences between a human’s stride and a cheetah’s stride?

What can a runner do in order to increase their top speed?

Time: 15 minutes

Activity 1Watch the video of the runner

Calculate their speed (note it is yards/sec – where are they running? Why is it in yards/sec?)

You will need a stopwatch to record their time

Compare the speed you calculated to the speed the people at your desk got

Why are there discrepancies? (Think back to last lesson)

Time: 10 minutes

Activity 2Now count the number of strides taken by the runner during the entire run

Use the number of strides and the total time to calculate the runners stride frequency in strides/sec

Stride frequency = number of strides

time (sec)

Time: 5 min

Activity 3Calculate the average length of one stride of the runner

How will you do this?

Calculate the runner’s speed using the “new” equation for speed: speed = stride frequency x stride length

Compare the results of your two speedsDo the equations agree on the speed of the runner?How good is the agreement?Explain any differences in results that you obtained

Time: 15 min

Activity 4Work through steps 4-8 on pg. 172 with your lab group

You may use the field or the covered court (whichever is not being used by the PE class)

Choose different people from Tuesday to be the recorder, runner, and measurer

Hand in your observations when you are completed

Time: 30 minutes

Closing & Homework

You may use whatever time is leftover to work on your chapter challenge

Homework:Read Physics Talk, pg. 173Physics to go, pg. 174 #1, 2, 4, 5, 6Stretching Exercises

Day 8: Projectile Motion & The

Shot PutLearning Objectives:Understand and apply the terms free fall, projectile, trajectory, rangeObserve that all projectiles launched horizontally from the same height strike a level surface in equal times, regardless of launch speedUnderstand that the vertical and horizontal components of a projectile’s motion operate independent of one anotherInfer factors which affect the range and shape of a projectile’s trajectoryMeasure the acceleration due to gravityUnderstand that the average speed at a specified time of an object which has fallen freely from rest is equal to half of the speed attained by the object at the specified timeApply the equation speed = gΔt to calculate the speed attained by an object which has fallen freely from rest

Starter

StarterA world record shot put record of 23.12m was set by Randy Barnes in 1990

What determines how far an object thrown into the air travels before landing?

Will a higher or lower launch point of a projectile increase range?

Will a particular launch angle increase range?

Will a greater launch speed of a projectile increase range?

Time: 15 min

Activity 1 – In lab groups

Place a coin on the edge of the table with about half of the coin hanging over the edge

Shoot another coin at this coin (off-center) so the coin hanging off the edge falls straight down and the shot coin falls with some projectile motion. Vary the speed of the projected coin.

Repeat as many times as necessary to answer the following questions:

Which coin hits the floor first?How does its speed affect the amount of time for either coin to fall to the floor?How does speed affect how far across the floor the projected coin lands?

Time: 15 minutes

Activity 2 - Group2 volunteers needed

1 person will push the other person in a chair at a constant speed

While the chair is moving, the person sitting will throw a ball up in the air and try to catch it

Before we begin, what do you think will happen?What do you observe about the ball’s trajectory (shape of the path) and the ball’s range (horizontal distance)? What happens when the speed of the chair is varied? What factors affect the range of the ball?What is the shape of the trajectory?

Time: 15 minutes

Activity 3 – Lab group

We will go outside and “shot put”

With your lab group, come up with a hypothesis on how the following affect the distance the ball can go:

Angle at which the ball is releasedSpeed at which the ball is releasedHeight at which the ball is released

Give everyone a chance to shot put and see how the different variables affect the distance it travels

Time: 30 minutes

HomeworkRead Physics Talk, pg. 178

Physics to Go, pg. 181 #3, 5, 6

For you to read, pg. 168

Physics to go, pg. 191 #1, 2, 12

Day 9: The Pole Vault (60 min)

Learning ObjectivesUnderstand and apply the equation KE = ½ mv2

Understand and apply the equation PE = mghUnderstand and apply the equation PE (spring) = ½ kx2

Understand and measure transformations among kinetic and potential forms of energy

Starter

StarterThe world record for pole vault is 6.14m

If good vaulters have a pole that is around 7m, why can’t they vault 7m?

What factors limit the height vaulters have been able to attain?

Time: 15 minutes

Activity 1 – Lab group

Work through steps 4-6 on pg. 195

How high does your coin travel with:1cm deflection?2cm deflection?3cm deflection?

How is the height the coin travels related to the amount of deflection of the ruler?

Activity 2You may use this time to work on your project which is due on Friday

You will not have to present your project to the class

Closing & Homework

Friday – in class assessment

For you to read, pg. 196

Physics to go, pg. 201 #1, 2, 4,

Day 10 – Summative AssessmentChoose 1 track & field event and explain the

physics concepts behind it. Things to consider include:

Energy conversionsDistance/speed/time data analysis throughout the event (graph)How can a person get faster/jump further or higher/throw farther?How do you determine who wins the event?How is the event measured?

Reflection of the unit