Seesaw

Seesaw

Pencil and paper
Overview
Connecting to the Curriculum
Marking Student Responses

Luke's dad built a seesaw using a long plank and a saw-horse.  Luke's father stood at his end and pushed the seesaw up and down.  He tried two different ways of doing this as shown in the diagrams.  

Diagram A Diagram B

 
a) Draw an arrow pointing to the position of the pivot (fulcrum) on Diagram A.
 
b) In which diagram does Luke's dad need to use less force to lift the seesaw?
 
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c) Luke and his father were sitting balanced on the see-saw.  Luke's mass was 30 kg and he was sitting 2 metres away from the saw-horse.  Luke's father had a mass of 60 kg. How far away from the saw-horse was his father sitting? [NOTE:  mass 1 × distance 1 = mass 2 × distance 2]
 
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Level:
5
Curriculum info: 
Science, Communicating in science, Physical World
Keywords: 
using physics, forces, levers, balance, equations
Description of task: 
Task: Answer questions about how a seesaw works and use an equation to calculate how to balance the seesaw.
Curriculum Links: 
Science capabilities
The capabilities focus is brought about by the conversations you have and the questions you ask.
 
Capability: Interpret representations
This resource provides opportunities to discuss the use of scientific formulae to predict relationships.
 
 

 
Science capabilities: 
Interpret representations
Making Better Sense: 
Shadows
Answers/responses: 
    Y10 (6/98)
a) An arrow drawn pointing at the saw-horse. easy
b) Diagram B difficult
c) 1 metre (30 × 20 = 60; 60 ÷ 60 = 1) moderate