Session C: Friction
Programme of study: Identify the effects of air resistance, water
resistance and friction, that act between moving surfaces
Working scientifically:
Plan
enquiries, including recognising and controlling variables where necessary
Take
measurements, using a range of scientific equipment, with increasing accuracy
and precision
Record data
and results using bar graphs
Report findings, including oral
explanations of results
Resources needed:
Sports shoes/trainers (1 each) that children bring in. Access to
different floor surfaces, force meters. Access to internet
(Gamified extras if required: Badges, Stamps, or stickers)
Whole class teaching:
Show the class the results of an enquiry that a group of
children carried out using a car on a ramp (shown below). Ask why does the car travel further on
some surfaces than on others? Do
children know the name of the force that is acting? Friction. How can we define friction? The resistance that one surface or
object encounters when moving over another or the action of one object rubbing
against another, which tends to slow it down or stop it completely.
Car on a Slope Enquiry
Some children carried out an experiment to find out what
happens when a car rolls down a slope covered in different surfaces. They
measured how far the car rolled each time.
Here are their results:
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On which surface did the car roll the furthest? On which surface did it roll the least distance?
Why does the car roll further on some surfaces than
others?
After the first discussion about the car experiment read the
following:
James is a young boy who loves to run, he wants to run as fast as he
possibly can. First of all, James tries running on the wet grass but he slips
over, then he tries to run on the beach, but his feet keep slipping through the
sand. James decides to come to you all for help, he wants to know what the best
surface would be for him to run on.
Open discussion about different types of surfaces starting with
the common such as tarmac, wood etc. and don’t be afraid to throw in some silly
hypothetical surfaces such as jelly. This is just an opening to incorporate the
discussion task into the narrative. After this discussion proceed to read the
following:
James now knows what surfaces to run on, but he is not allowed
running shoes when he’s at school. In groups of 3-4, James would like you all
to pick which of your shoes have the best grip from their soles tread. To make
it interesting James will give a point for each member of the team with the
highest friction shoe. Teams only get to pick once so choose wisely and
remember to record your results when testing.
At this point hand out Newton meters and start the clock. At the
end of the 15 minuets (scale to fit time left in the lesson).
After the time is up test the nominated shoes for each team and
record the measurements on the board to help promote engagement and excitement
for the competition. Once all scores have been recorded read out the following:
After seeing the results James has chosen (Students Name)’s shoes to
run in as they offer the most friction and will enable him to run the fastest.
After years of running, James eventually grew up to be an Olympic runner all
thanks to the class’ help.
When this has finished award the points to each winning team
member.
Group activities:
Adult-led activity:
Tell the children that they are going to test their sports shoe
to see which surfaces their shoe works best on. As a class decide on up to six
contrasting floor surfaces – examples; grass,
tile, carpet, polished wood, concrete, gravel. Ask the children to predict on
which surface their shoe will be hardest to pull - most force required = most friction – encourage children to try to give
scientific reasons, not simply observations based on daily life. In groups
compare shoes. Which will have the best grip – most force required = most friction?
Children write down their predictions (session resource). Plan the
method as a class – which factors will need to stay the same to ensure that
this will be a fair test? Work together in small groups. During the test
children should record their measurements on the table using the session resource, draw bar
charts to make the data easier to interpret and discuss the results. Children
should make three measurements each time and calculate the mean (average) by
adding all three measurements and dividing by three. If one measurement
differs greatly from the other two an extra measurement should be taken instead
to check. What do the results
show? Which surface
allowed the shoe to move with less effort due to less friction? Was this the
same surface for everyone’s shoe? Which surface required the most effort to get
the shoe to move due to increased friction between the show and the surface? Discuss the results as a whole,
giving individual children the opportunity to present their group’s findings. Whose shoe would provide the best
grip in each location? What is it about the shoe with the best grip that causes
it to generate friction when in contact with the floor? Would children make any
changes to their enquiry if they did it again?
I can:
1. Define friction as a force acting
between moving surfaces.
2. Carry out a fair test; recording accurate
results in a table.
3. Compare my results with others
and draw conclusions.
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