EPISODE 4: RECIPE FOR DISASTER
THE INCLINED PLANE
TO TEACHERS AND PARENTS
A large focus in teaching science is around encouraging both curiosity
and the skills and dispositions to be able to find out or test things for
yourself. This includes developing an understanding about how science
itself works. The New Zealand Curriculum calls this the Nature of Science.
Tips about how to encourage these aspects are given in a
Use these to get your children talking, discussing, testing and thinking
about the science involved in Jiwi’s Machines. Have fun! The science
content involved in Jiwi’s Machines relates to the Physical World
Achievement Aims of the New Zealand Curriculum.
THE INCLINED PLANE
The Inclined Plane was first introduced in EPISODE 1: TOAST POP. There it was
described as a flat surface with one end higher than the other. The Inclined Plane
or Ramp is a type of simple machine that can be used in two ways. It can help to
lift objects up using less effort (in the way that the Egyptians built the pyramids)
or to reduce and control the force at which something falls. In TOAST POP we
explored how objects roll down an Inclined Plane. Now the focus is about how
the Inclined Plane can be used to make work easier for us. Luke demonstrates the
idea that it is often easier to push something heavy up a ramp rather than lift it
ourselves.
HOW DOES USING AN INCLINED PLANE WORK?
Using an Inclined Plane does not change the actual weight of the object you are
lifting, but it does reduce the effective weight of that object. A large portion of the
weight, when using an inclined plane, is supported by the ramp itself. This means
the actual weight is shared between the person doing the lifting and the ramp.
How much is supported by the ramp and how much by the person depends on the
angle of the ramp.
INVESTIGATION:
HOW DOES USING AN INCLINED PLANE
HELP LIFT AN OBJECT?
(1 hour)
BIG SCIENCE IDEA: AN INCLINED PLANE
MAKES IT EASIER TO SHIFT HEAVY
OBJECTS BECAUSE IT SUPPORTS SOME
OF THE OBJECTS’ WEIGHT.
For this investigation you will need a
weight (eg: bag of rice), a strong rubber
band, tape measure or ruler, a ramp and a
stack of books or height for the ramp.
Loop the rubber band firmly around the
top of the bag of rice.
Stack the books up.
Using the rubber band, hold the bag of
rice at the top of the stacked books. It
will stretch out a long way. Use the tape
measure or ruler to measure how far it has
stretched and record that distance.
This gives us a number to represent the
amount of effort needed to lift the weight.
Now place the ramp on top of the stack of
books and make an inclined plane. Lie the
weight at the bottom of the inclined plane
and pull it up by the end of the rubber
band. When the weight gets to the top
of the inclined plane measure how much
the rubber band is stretched. Record this
number.
USE EVIDENCE
Students should be encouraged to ask
and answer questions such as:
How do you know that?
What makes you think so?
What evidence do you have
to back up your thinking?
JIWI WONDERS
• What does this tell us about using an inclined plane to shift a weight?
•
What would happen if the ramp was steeper? Shallower? Try.
•
BRAINSTORM: Where have Inclined Planes been used throughout history to make
work easier?
DO YOU KNOW: Do the children realise that a road up a steep hill is an inclined plane?
Using all your knowledge, which road up the mountain do you think will be the easiest on
the car? Why?
Have you seen the shape on the right before? It is just like a screw. In fact, a screw is an
inclined plane wrapped around a cylinder.
MATERIALS
Activity 1
Weights like a bag of rice
Strong rubber bands
Stack of books or height for
ramp
Inclined plane or ramp
Measuring tape or ruler
NZ CURRICULUM PLANNING SUMMARY
Contextual Achievement Objective:
PHYSICAL WORLD; Explore and investigate
physical phenomena in everyday situations.
Nature of Science Achievement Objective:
INVESTIGATING IN SCIENCE; Science learning
can be improved by encouraging appropriate
attitudes.
Big Science Idea: An inclined plane makes it
easier to shift heavy objects because it supports
some of the objects’ weight.
Big Nature of Science Idea: Some
characteristics of scientists are curiosity &
honesty (in recording and validating data).
Weblinks: http://scienceonline.tki.org.nz/Nature-
Capability focus:
USE EVIDENCE; Students should be encouraged
to ask and answer questions such as:
How do you know that?
What makes you think so?
What evidence do you have to back up your
thinking?
of-science/What-is-the-Nature-of-Science/Teachersuggestions-Investigating-in-science/Improvinglearning-by-encouraging-appropriate-attitudes
http://scienceonline.tki.org.nz/Introducing-fivescience-capabilities/Use-evidence