Session C: Friction
Whole class teaching: (links to sessions 7, 11 & 12, Citius, Altius, Fortius
Theme, UKS2 Olympics Topic)
Show the
class the results of an enquiry that a group of children carried out using a
car on a ramp (session resources).
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.
Look at the soles of the shoes bought in
by the children; allow them to take a rubbing using wax crayon. Discuss why
sports shoes/trainers often have many ridges and bumps to help them grip – changes of direction in sports, when you are
moving fast, etc. Some sports shoes are even designed with a particular
surface in mind!
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?
Lesson Materials
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:
|
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?
Shoe Friction
We wanted to find out how much force was
needed to move a sports shoe across different surfaces.
We
needed:
·
A sports shoe/trainer
·
A force meter
·
A selection of surfaces
Prediction:
I predict that the surface causing the most
friction will be ____________________.
I predict that ________________’s shoe will
have the best grip.
The
experiment:
We
attached our force meter to our shoe and placed it on each surface.
We
recorded the amount of force needed to start the shoe moving.
We
made it a fair test by ________________________________________________
_____________________________________________________________________
The
results:
Surface
|
Force
needed to start shoe moving (newtons)
|
Conclusion:
The sole of the shoe had the best grip on
______________. With more friction
between the shoe and the surface, more force was needed to make the shoe move.
________________’s shoe had the best grip.
References
No comments:
Post a Comment