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...investigating speed...









Bigger! Better! Faster! MORE!




• Know that lots of factors affect the speed of a lego car.



• Be able to decide on the variables for your investigation.



• Be able to carry out a practical task to collect data, and use this data to calculate the speed of a lego car.



• Be able to graph your data, write a simple conclusion, and use scientific ideas about energy to explain your results.













Task 1 - Starter





Scream if you want to go faster, okay?





Find someone who knows the ten forms of energy, and which types can be stored.



Solve the problems below, using the equation triangle you learned last lesson:









1) Usain bolt runs 100m in 9.6 seconds. What is his speed?


2) A cyclist travels 1800m at a speed of 6m/s.  How long does it take?


3) A car travels at 24m/s for 5 minutes.  How far does it travel?





• Explain why the speed you calculated for Usain Bolt is only an average speed.

• The car in question 3 travels at 24m/s.  What is this speed in metres per hour?  What is this speed in kilometres per hour?















Task 2 - Investigating speed





What will change the speed of the Lego car?




Discuss in pairs or threes:



What might change the maximum speed a Lego car reaches as it rolls down a ramp?



• How does each factor affect the kinetic energy of the car?









Choosing your variables




Nice car.








• one factor to investigate as your independent variable.



the values you will test.



what you will measure

(the dependent variable).



a basic method for your experiment.





Your teacher may ask some of you to share your ideas with the class.














Task 3 - Carry out your method





Calculations!  Yeah!





Collect your apparatus, which will include some of the following:



     ▪ A ramp


     ▪ A clamp stand


     ▪ A lego car or dynamics trolley


     ▪ A stop clock


     ▪ A metre ruler




You have 15 minutes to collect your data!



Extension: check the data you have collected to see if there are any anomalous results.  Can you explain what has caused these anomalies?  Repeat these measurements, if you have time!



Teacher note: light gates can be used in place of stop clocks, at your discretion.












Task 4 - Calculate the speed




Calculate them numbers!




For each measurement, calculate the speed of your lego car in centimetres per second.



Use the formula you learned last lesson.




D = S × t





Make sure you give your answer to a suitable level of precision.  How many decimal places should you use for your answers?













Task 5 - Graphing




Graphs!  Woop woop!




Draw a scatter graph of your results.



Follow the five points below to make sure you draw a good graph.







Rules for a good graph





• The independent variable goes on the x-axis.


• The dependent variable goes on the y-axis.


• Both axes should start at zero.


• The numbers should be evenly spaced, and go up in equal intervals.


• Both axes should have descriptive labels, and units.














Graphs!  Woop woop!




What kind of relationship does the graph show?



1) Is the line of fit straight?  Does it start at the origin?


2) Is the relationship between the variables proportional?


3) Use your graph to help you write a simple conclusion.

















Homework :)

Woop woop!




1) Complete the Alfie homework task.


Click here, or follow the link below:





2) Revise for the test next lesson!