Lifting rocks

Lifting rocks

Pencil and paperOnline interactive
Overview
Using this Resource
Connecting to the Curriculum
Marking Student Responses
Further Resources
This task is about exploring levers and distance to the pivot point. 
How to do this task

  • Set up the experiment in the diagram.

diagram of a pivot

  • Tape or blu-tack a small rock on one end of the 40 cm ruler.
  • Place known masses on the other end of the ruler till the ruler end with the rock begins to lift off the bench. Carry out enough investigations to complete the table below.

Question 1Change answer

a)  Complete the table below from your experiment results.
Distance from pivot Mass required to lift ruler from bench
20 cm
15 cm  
10 cm  
5 cm

Question 1Change answer

b)  Write a statement about what your results show.
Task administration: 
This task can be completed with equipment and pencil and paper or online.
 
Equipment:
40 cm wooden ruler; a mass e.g., a rock; known masses; pivot e.g., a pencil; blu-tack.
  • Distances used in the table will depend on the length of ruler used.
  • 1 m rulers or plastic rulers which are too flexible will not work.
Copyright: 
Image copyright: NZCER
Level:
5
Curriculum info: 
Science, Investigating in science, Physical World
Keywords: 
using physics, forces, levers, experiments
Description of task: 
Task: Investigate mass required to lift a small rock when changing distance from pivot. Assessment focus: levers.
Curriculum Links: 
Science capabilities
The capabilities focus is brought about by the conversations you have and the questions you ask.
 
Capability: Gather and interpret data
This resource provides opportunities to discuss:
  • the importance of precise observations and measurement when gathering information.
  • looking for patterns in the data.
 
Science capabilities: 
Gather and interpret data
Answers/responses: 

a)

Table complete and shows a correct pattern, i.e., increasing mass needed the closer they are to the pivot.
Table complete.

b)

A correct statement of what their results indicate, e.g., "The closer to the pivot, the greater the mass required to lift the rock."