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TRANSCRIPT
ScienceYear 7 Physics
Motion
Notes & Experiments
Name: ________________Teacher: ______________
YOU MUST KEEP THIS BOOK
[INSERT SCHOOL LOGO HERE]
MY UNDERSTANDING CHECKLIST
I can… Textbook Page
Before the Topic
After the Topic
Measuring SpeedState the relationship between speed, distance and time 98
Describe an Investigation to measure the speed of an object 99
Compare an object moving at 2 (or more) different speeds using a distance-time graph.
100 – 101
Working with Ticker TapeIdentify that both distance and time must be measured to find the speed of an object 99
Use a ticker tape to determine the speed of an object -
Describe how your results can show whether or not the speed of the object is changing 101
Working with Light GatesDescribe a more accurate method for measuring the speed of an object -
Use a pair of Light Gates to determine the speed of an object -
Know the difference between accuracy and precision and give ways to improve both 4
Distance-Time GraphsPlot/Sketch a distance-time graphs 100Interpret the shape of a distance-time graph and use it to describe the motion of an object.
100 – 101
Calculate the speed of an object by calculating the gradient of a line on a distance-time graph 101
MY SKILLS CHECKLIST
I can… Before the Topic After the TopicCalculate the speed of an object by measuring time and distance.Programme Light Gates to measure timeGive ways to improve the accuracy of an investigationIdentify the key elements of graph and plot accurately on a set of axes
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KEY WORDS
Some of the key words and definitions are missing some information! Can you complete them?
Key Word Image/Diagram Definition
Speed
A measure of how fast or how ________ an object is moving. This can be measured using lots of units including:___________________ (m/s)___________________ (mph)
DistanceA measure of the length between 2 points. This is usually measured in ___________ (m)
TimeA measure of how long it takes something to happen. This is usually measured in _________ (s)
Accelerate This is when an objects speed ___________.
Decelerate This is when an objects ______ decreases.
Distance-Time Graph
A graph which has ________ on the y-axis and ________ on the x-axis. We can calculate speed from this graph by finding the _________ of the line.
Ticker Timer A machine that punches ________ into Ticker _______ at regular intervals. We can use it to determine _________.
Ticker TapeThis is used in a machine called a ________ _________.
Light GateA device that can be used to measure _______. It makes measurements when an object interrupts the light ray as it passes through the gate.
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Lesson 1: Measuring Speed
LEARNING OBJECTIVES:DEVELOPING STATE THE RELATIONSHIP BETWEEN SPEED, DISTANCE
AND TIMESECURE DESCRIBE AND INVESTIGATION TO MEASURE THE SPEED
OF AN OBJECT
EXTENDING COMPARE AN OBJECT MOVING AT 2 (OR MORE) SPEEDS USING A DISTANCE-TIME GRAPH
SCIENTIFIC SKILLS CALCULATE THE SPEED OF AN OBJECT BY MEASURING TIME AND DISTANCE
Do Now: Solve the Anagrams
Solve the anagrams to find some of the key words for this topic.
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Can you write a physics statement linking at least 3 of the words above?
mite edsep
eaetcarelc ascdntei
teeledacreocfer
STRETCH
Speed, Distance and Time
When an object is moving we can measure 2 key quantities for it:
The time that the object is moving for. We measure this in _____________ (s)
The distance that the object travels in that time. We measure this in _________ (m)
Once we have the time taken and the distance travelled we can calculate how fast the object was moving. We call this the objects speed. This is measured in _____________________ (m/s)
Speed, Distance and Time are linked in the following equation:
Speed ( s )=
Which can be represented in the following equation triangle:
Worked Example:
Meredith travels 850m in 200s. How fast must she have been travelling?
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Calculations: Speed, Distance and Time
Can you use the equation triangle to answer the following questions?
1. Calculate the speed of an object that travels 150 meters in 12 seconds.
2. Calculate the speed of an object that travels 600 meters in 2 minutes.
3. How long will it take an object to travel 450 meters if it travelling at 20 m/s?
4. How far will and object travel in 25s if it is travelling at 43 m/s?
5. How far will an object travel in an hour if it is travelling at 10 m/s?
PEER MARKING (1 mark for working, 1 mark for answer, 1 mark for units)
Score [/15] To Progress:
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Investigation: Measuring an objects speed
We do not have an instrument to measure speed.
Instead we must measure 2 other quantities:
1. Time using a __________________
2. Distance using a __________________________
Once we know these quantities we can calculate speed using the following equation:
Speed=¿
The Method:
1. Use the trundle wheel to measure out 8 sections (each 5 meters apart)2. Allocate 2 people with stopwatches to each of the 8 sections. 3. Everyone starts the stopwatch when the walker leaves the starting line.4. Each section will stop their stopwatch when the walker passes their section.5. Repeat the experiment with someone running.6. Make sure you write down your numbers ready to share with the class.
My ResultsI am measuring time at
section…
Time for walker (s)
Time for runner (s)
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Start Timer 1 Timer 2 Timer 3 Timer 4
5m
Health and Safety Check!
I will run carefully and be aware of any wet surface
Walking Results
SectionDistance
(m)
Time Taken (s) Speed
(m/s)1 2 Average
1 5
2 10
3 15
4 20
5 25
6 30
7 35
8 40
Running Results
SectionDistance
(m)
Time Taken (s) Speed
(m/s)1 2 Average
1 5
2 10
3 15
4 20
5 25
6 30
7 35
8 40
Investigation Conclusion: Plotting and comparing your results
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Now plot your result onto the graph below using a suitable scale:
Y-axis = Distance X-axis = Time
It may be a good idea to plot the walking and running results in different colours.
You are going to end up with two lines of best fit.
Use your results to answer the following questions:
1. Why did we have 2 people timing at each section?
2. How are the graphs different for walking and for running?
3. What do you notice about your calculations for speed in your walking and running results tables?
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Can you sketch on the graph below a line to show:
1. An object that is travelling faster (in blue)
STRETCH
Distance (m)
Time (s)
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Can you sketch on the graph below a line to show:
1. An object that is travelling faster (in blue)
Time (s)
Distance (m)
Lesson 2: Working with Ticker Tape
LEARNING OBJECTIVES:DEVELOPING IDENTIFY THAT BOTH DISTANCE AND TIME MUST BE
MEASURED TO FIND THE SPEED OF AN OBJECTSECURE USE A TICKER TIMER TO DETERMINE THE SPEED OF AN
OBJECTEXTENDING DESCRIBE HOW YOUR RESULTS CAN SHOW WHETHER OR
NOT THE SPEED OF THE OBJECT IS CHANGINGSCIENTIFIC SKILLS GIVE WAYS TO IMPROVE THE ACCURACY OF AN
INVESTIGATION
Do Now: Speed, Distance and Time Calculations
1. If you move 50 meters in 10 seconds, what is your speed? (3)
2. You arrive in my class 45 seconds after leaving Maths which is 90 meters away. How fast did you travel? (3)
3. A plane travels 395,000 meters in 9000 seconds. What was its speed? (3)
4. It takes Serine 0.25 hours to drive to school. Her route is 16 km long. What is Serine’s average speed on her drive to school (in m/s)? (5)
Score [ /14]
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Investigation: Speed with Ticker Tape
To find the speed of an object you need to measure 2quantities. These are:
1.
2.
In today’s investigation you will be using a ticker timer and ticker tape.
The Ticker Timer has a ___________ ______ which has a needle on the end.
The bar vibrates with a frequency of ______ Hzwhich means it makes ________ dots every second.
This means that the time taken to make ____dots will always be 1 second!
You can measure the distance travelled in onesecond by measuring the distance from the 1st dot to the ________ dot. This is the same as ______ spaces.
Worked Example:
A student uses a ticker time with a frequency of 50 Hz and gets the following results:
How fast was the object moving?
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Health and Safety Check!
I will keep my fingers awayfrom the vibrating pin
Task 1 : Slow Speed
Method: Pull the tape through slowly at a constant speed for at least 2 seconds.
Task 2: Fast Speed
Method: Pull the tape through quickly at a constant speed for at least 2 seconds.
Task 3: Accelerating
Method: Pull the tape through the timer for at least 5 seconds. Start of slowly and gradually get faster.
Worksheet:
TAPE DESCRIBE THE MOTION SHOWN
A
B
C
STRETCH: Calculate the speed of object A
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Science Skill: Conclusions from your investigationUse your observations and results to answer the following questions:
1. Describe the difference in the layout of the ‘dots’ in the slow ticker tape compared to the fast ticker tape.
2. How could you tell from the spacing of the dots in Task 3 that you had been increasing your speed?
3. Deceleration:a. What would happen to the spacing of the dots if you had decreased
your speed?
b. Sketch these dots on the ticket tape below:
4. The following is a result from a ticker tape investigation.
a. Sketch the dots for an object moving slower.
b. Sketch the dots for an object moving faster
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STRETCH: Sketch the dots for an object that first speeds up then slows down again.
Key Ideas: The Ticker Timer
When the dots are close together the object is moving SLOW When the dots are far apart the object is moving FAST When the dots are getting further apart out the object is ACCELERATING
(GETTING FASTER) When the dots are getting closer together out the object is
DECELERATING (GETTING SLOWER)
Science Skill: Comparing methods of measuring speed
In your own words, state which of the 2 methods of measuring speed gives more accurate results and explain your reasons why.
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2. Describe the motion in the following graph:
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STRETCH
Assessed Worksheet: Linking Forces and Motion
Use your knowledge from the Forces topic to complete the following worksheet.
CG Score: To Progress:
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Lesson 3: Working with Light Gates
DEVELOPING DESCRIBE A MORE ACCURATE METHOD FOR MEASURING THE SPEED OF AN OBJECT
SECURE USE A PAIR OF LIGHT GATES TO DETERMINE THE SPEED OF AN OBJECT
EXTENDING KNOW THE DIFFERENCE BETWEEN ACCURACY AND PRECISION AND GIVE WAYS TO IMPROVE BOTH
SCIENTIFIC SKILLS PROGRAMME LIGHT GATES TO MEASURE TIME
Do Now: Interpreting Ticker Tape
Describe the motion of the objects which produced the following ticker tapes:
TAPE DESCRIBE THE MOTION SHOWN
A
B
C
D
E
STRETCH: Calculate the speed of object A and C
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What are Light Gates?
Your teacher is going to explain to you what Light Gates are.
Task:
In the space below you should write your own explanation of what they are and how they work. You may wish to draw a diagram to help your explanation.
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Science Skill: Programming Light Gates
Your teacher is going to show you how to programme the easy sense vision data logger.
This will allow the light gates to measure time for you.
In the space below, make notes to help you remember how to programme your machine when you do the investigation.
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Diagram:
Steps to programme the easy sense vision:
Investigation: Speed with Light Gates
In this investigation you are going to find the speed ofan object using Light Gates.
We will programme the Light Gates to tell us the timeit takes the object to get from one light gate to the other.
What other measurement are we going to need to make? _____________________
Method
1. Set up the equipment as shown in the diagram(You will need to use clamp stands to hold the light gates)
2. Set up your light gates to measure the time it takes the trolley to pass from one to the other.
3. Measure the distance between the light gates using a ruler.4. Release the trolley and read the value for time off the screen (add this to the
table)5. Increase the height of the ramp and repeat
Results and Conclusions
Add units to the table before adding your results.
Distance between Light Gates = ________ ____
Height of Ramp ( )
Time Taken ( )
Average Time Taken ( )
Speed of Trolley ( )
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Health and Safety Check!
I will be sensible and make sure the trolley doesn’t falloff the bench
Investigation Conclusion: Plotting and comparing your results
Now plot your result onto the graph below using a suitable scale:
Y-axis = Speed of Trolley X-axis = Height of Ramp
Use your results and experience to answer the following questions.
1. What happened to the speed of the trolley as you increased the height of the ramp?
2. Can you use your Forces knowledge to explain why this might be?
3. What quantities have to be controlled (kept the same) during the investigation?
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4. Why is it important to keep these the same throughout the investigation?
5. Can you think of another investigation in which light gates could be used to give more accurate results?
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There are many other different ways to get more accurate measures of distance and time. Some of them are show below:
STRETCH
Assessed Worksheet: Accuracy and Precision
A good analogy for understanding accuracy and precision is to imagine a basketball player shooting baskets. If the player shoots with accuracy, his aim will always take the ball close to or into the basket. If the player shoots with precision, his aim will always take the ball to the same location which may or may not be close to the basket. A good player will be both accurate and precise by shooting the ball the same way each time and each time making it
in the basket.
Section A: Using the above analogy can you describe each of the terms in your own words:
Precision:
Accuracy:
Section B: Above there are 3 targets A, B, C and D. Use these to answer the following questions:
1. Which of the target(s) shows precise shooting? ________________
2. Which of the target(s) shows accurate shooting? ________________
3. Do any of the targets show neither precise nor accurate shooting? ___________
Section C: Illustrate the indicated accuracy and precision on the targets below:
CG Score: Next Steps:
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DCBA
Accurate but not Precise
Precise but not Accurate
Lesson 4: Distance – Time Graphs
DEVELOPING PLOT/SKETCH A DISTANCE-TIME GRAPH
SECURE INTERPRET THE SHAPE OF A DISTANCE-TIME GRAPH AND USE IT TO DESCRIBE THE MOTION OF AN OBJECT
EXTENDING CALCULATE THE SPEED OF AN OBJECT BY CALCUATING THE GRADIENT OF A LINE ON A DISTANCE-TIME GRAPH
SCIENTIFIC SKILLS IDENTIFY THE KEY ELEMENTS OF GRAPH AND PLOT ACCURATELY ON A SET OF AXES
Do Now: Quick Quiz
1. What two forces are acting on a stationary, floating ship? (2)
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2. How do we represent Force in a diagram? (1)
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3. What are the units of Force? (1)
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4. An object has a mass of 35kg on Earth (g = 10 N/kg). How much does the object weight? (3)
5. A cyclist is travelling at 8m/s. How long will it take him to cycle 5km (5000m)? (3)
6. Describe the motion of the object that create the ticker tape below: (1)
…………………………………………..…………………………………………..
7. In what direction does Friction act? (1)
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Score [ /12]
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Distance-Time Graphs
When we plot a distance-time graph we must make sure that:
We plot distance ( ) on the y-axis (vertical axis)
We plot time ( ) on the x-axis (horizontal axis)
Below there are 4 sets of axis.
1. Label the x and y axis in each example2. Sketch a graph on each axis to match the description
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Constant Speed Stationary
Getting Faster Getting Slower STRETCH
Plotting/Sketching Distance-Time Graphs
Worked Example:Draw a distance/time graph to show this motion of a car:
A car starts at rest (not moving). It then travels 50 meters in 5 seconds. Then it stops for 2 seconds. It then travels 20 meters in 4 seconds.
Key things to remember:
You may wish to make some notes below while you work through the above example.
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Worksheet: Plotting/Sketching Distance-Time Graphs
In each question, plot the journey described on a distance-time graph.
Question 1Louise sets off on her bike from her house. She travels 100m in 20s. For the next 200m she takes 30s. She then stops for 30s to have a sip of water.
Question 2A biker gets on his motorbike. He drives out of the car park, covering 25 meters in 5 seconds. Now on the main road, he travels 240 meters in 8 seconds. As the biker approaches traffic lights, he decelerates over 3 seconds, covering 35 meters. He comes to a complete stop. He waits at the traffic lights for 4 seconds.
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STRETCH: Question 3: Adam starts running on the starting pistol. She runs the 100 meters in 12 seconds.
Belle starts running from the 25-meter mark. He reaches the finish line in 15 seconds.
Carole starts running two seconds after the starting pistol. He crosses the finish line at the same time as Adam.
Darren runs the full 100 meters at 11 meters per second. He started running at the sound of the starting pistol.
Elliot started running at the starting pistol at 8 meters per second, but gave up after 7 seconds.
Which runner won the race?
The winner is ___________________.
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Calculating speed from a distance-time graph
We have already seen that when the line on a distance time graph is steeper or more sloped, the object is travelling faster.
This is because the speed is equal to the gradient on a distance-time graph. We calculate the gradient using the following equation:
gradient= change∈ ychange∈x
Worked Example:Find the speed of the object between points:
1. A and B2. C and D
Worksheet: Calculating Speed from a distance-time graph
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Question 1
Question 2Find the speed of the object between points:
1. A and B2. C and D
Question 3:Label on the objects speed at each of the 3 stages of it’s journey.
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In the space below, can you draw a distance time graph for your journey to school?Remember to consider junctions, traffic lights as well as speed limits on different
types of road.
Question 4Find the speed of the object between points [look at the units: 1km = 1000m]:
1. A and B2. C and D3. E and F
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STRETCH
In the space below, can you draw a distance time graph for your journey to school?Remember to consider junctions, traffic lights as well as speed limits on different
types of road.
Calculation Space:
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Motion: Past Paper Questions
Q1. Josh has a helium-filled balloon.
(a) He wants to calculate the speed of his balloon as it rises to the ceiling.
(i) What two measurements should he take to calculate the average speed of his balloon?
1 ..........................................................................................................
2 ..........................................................................................................
2 marks
(ii) How can he use these measurements to calculate the speed of his balloon?
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1 mark
(b) Josh attached different masses to his balloon. For each mass, he calculated the speed of rise of the balloon. His results are shown below.
mass(g)
speed of rise(mm/s)
0 120
10 60
20 40
30 –20
40 –70
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(i) How does the table show that the balloon went downwards?
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1 mark
(ii) Josh plotted two points on the graph as shown.Complete the graph by plotting the missing points and draw a line of best fit.
2 marks
(iii) From the graph, find the mass needed to keep the balloon floating in one place.
........... g
1 mark
maximum 6 marks
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Q2. A remote-controlled car was timed over a period of 10 seconds.A graph of distance against time is shown below.
(a) Describe the motion of the car between:
(i) 2 seconds and 6 seconds;
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1 mark
(ii) 9 seconds and 10 seconds.
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1 mark
(b) Calculate the average speed of the car between 0 and 10 seconds.Give the unit.
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2 marks
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Q3. (a) The ‘two second rule’ is a rule for car drivers. The rule is as follows:
‘Leave enough space between you and the vehicle in front so that you can pull up safely if it suddenly slows down or stops… A two second time gap may be sufficient… Use stationary objects (eg lamp-posts) to help you keep a two second gap.’
(The Highway Code, 1993)
(i) The traffic is moving at 20 m/s, and a driver is keeping to the ‘two second rule’.What is the distance between the driver and the car in front?
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1 mark
(ii) The traffic increases its speed to 25 m/s, but the driver stays the same distance from the car in front.She sees the car in front pass a lamp post.How long will it take her to reach the same lamp post?
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1 mark
(b) The driver decides to check her speedometer while driving along a motorway.She measures how long it takes her to travel 6 km. It takes her exactly 4 minutes.What was her speed in km/h? Show your working.
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............................................................................................................ km/h
2 marks
Maximum 4 marks
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Q4. (a) Satish poured some water into a long tank in the school laboratory.He used a plunger at one end to make a wave.
not to scale
(i) The wave travelled to the other end of the tank.The speed of the wave was 2 m/s.
How long did the wave take to travel to the other end?
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1 mark
(ii) Satish investigated how the depth of water in his tank affected the speed ofthe waves.Write a plan to show how he could do this.
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3 marks
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(b) Satish found the following information about waves in the sea.
The diagram below shows how the depth of sea water changes.
Use the information in the table above to help you describe the speed of a waveas it travels from A to B and from B to C.
A to B ............................................................................................................
1 mark
B to C ............................................................................................................
1 mark
maximum 6 marks
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depth of sea water(m)
speed of wave(m/s)
10 9.9
20 14.0
30 17.2
40 19.8
Q5. A cyclist goes on a long ride. The graph shows how the distance travelled changes with time during the ride.
(i) Between which two points on the graph was the cyclist moving at the fastest speed?
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(1)
(ii) State one-way cyclists can reduce the air resistance acting on them.
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(1)
(iii) How long did the cyclist stop and rest?
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(1)
(iv) Write down the equation which links distance, speed and time.
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(1)
(v) Calculate, in km/hr, the average speed of the cyclist while moving.
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Average speed = .............................. km/hr
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(3)
Q6. A video recorder is loaded with a tape which plays for 180 minutes.The length of the tape is 260 m.
(a) (i) Calculate the speed of the tape, in metres per minute.
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……………………………………….……………………………… m/min
1 mark
(ii) What is the speed of the tape in metres per second?
…………………………………….…………………………………. m/s
1 mark
(b) To rewind the tape quickly, a different motor is used, which rewinds the tape at a maximum speed of 1.08 m/s.
(i) At this speed, how long would it take to rewind the tape completely?Give the units.
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1 mark
(ii) In fact, it takes slightly longer than this to rewind the tape.Explain why.
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1 mark
Maximum 4 marks
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Extra Notes Space
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