Mechanisms

 This topic covers the relationship between force, area and pressure; calculating force, area and pressure using the equation; calculating values in a hydraulic pressure system; and describing use of hydraulics on racing boats.

The resources in BT STEM Crew can be used either in sequence or flexibly as an introduction to a topic, or for a quick activity.

Introduce the topic of mechanisms with a short starter film, discussing how levers, pulleys, gears and hydralics are used to steer the boat. Test students' knowledge with an engaging interactive. Our differentiated worksheets reinforce learning objectives for this topic.

Film

 How do wings, hulls and grinders work to operate and control the boat? Find out about the different mechanisms used to get the best performance.

Interactive quiz

See how much your students know about force, area and pressure to understand how the Land Rover BAR team analyse the boat hydraulics to maximise their performance.

Launch interactive

Worksheets

Test students' learning with these differentiated worksheets.

Worksheet 1

11-14 lower

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Worksheet 2

11-14 higher

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Worksheet 3

14-16

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Practical Investigation

Students carry out a practical investigation into pressure and hydraulic systems, by looking at real mechanisms and performing calculations.

Practical Investigation: Presentation

11-14

Download PPT

Practical Investigation: Lab Sheet

11-14

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Practical Investigation: Teacher Guide

11-14

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Teacher's notes

Starter

To introduce the topic you could have a pair of tools to show students, such as embroidery scissors and kitchen scissors, wire cutters and bolt cutters, or large and small spanners. Ask them what the advantages and disadvantages of each are, and elicit the idea that the longer handles make it possible to exert a larger force at the cutting point/nut.

Suggested activity

Students investigate the force needed to lift a given mass with a single pulley, two pulleys, etc. Also measure how far the force has to move to lift the mass by a given amount, and work out that force x distance is always the same (with allowances for friction). Suggest similar hydraulic activity with syringes and tubes.

Plenary

Find images on the internet of an open sailing dinghy and ask them to identify similarities and differences between this and the racing boat in terms of simple machines. They should point out that both use pulleys to control the sail, both have tillers, but the dinghy does not have winches or hydraulics. Ask them to suggest why this is (less force needed as a much smaller sail area) and if this is so, why pulleys etc. are still needed (crew not usually as strong!)

Further ideas/ STEM Club ideas

Find out about capstans used on old ships (before steam power) to raise anchors etc. – how are they similar and different to the winches on the Land Rover BAR boats? (much bigger, worked by longer bars and many men, no gears)

Curriculum links

England

KS3 NC Science – Physics

Energy changes and transfers

  • Simple machines give bigger force but at the expense of smaller movement (and vice versa): product of force and displacement unchanged

Forces

  • Moment as the turning effect of a force
  • Forces: associated with deforming objects; stretching and squashing – springs; with rubbing and friction between surfaces, with pushing things out of the way; resistance to motion of air and water
  • Measurements of stretch or compression as force is changed
  • Force-extension linear relation
  • Work done and energy changes on deformation

KS3 NC D&T– Physics

  • Understand how more advanced mechanical systems used in their products enable changes in movement and force

GCSE D&T

AQA D&T Systems and control

  • Motion: understand methods of changing the direction or distance of an output;
  • Mechanical systems: Candidates should understand how mechanical advantage can be gained using levers and gears.
  • Friction: Candidates should understand the application of friction and explain methods used to reduce friction.

OCR D&T Product design

  • Systems and structures: Natural and mechanical structures, simple mechanical and electrical systems.
  • Scientific principles: The importance of scientific principles in common products such as levers, and mechanisms on bicycles ; understanding how modern scientific principles and new materials have influenced the design of products.

Wales

KS3 Science

  • Understand the forces in devices and their relationship to work done and power

KS3 Design & Technology

  • Learn about the properties and characteristics of mechanical components and apply this knowledge and understanding when designing and making products

GCSE Physics 

WJEC

  • Demonstrate and apply knowledge and understanding of the concept of pressure qualitatively and select and use the relationship: force = pressure / area

GCSE D&T, Systems and Control

WJEC

  • Understand that mechanical systems transmit motion and convert types of motion

Scotland

Third level Science

  • Collaborate in investigations into the effects of gravity on objects and predict what might happen to their weight in different situations on Earth and in space

Fourth level Science

  • Gain knowledge of how formulae may be used in the context of energy transfer and mechanical systems and apply them to solve problems, for example in engineering

National 5 Physics

  • Use of an appropriate relationship to solve problems involving pressure, force and area

Northern Ireland

KS3 Science & Technology

  • Incorporate control systems, such as mechanical, electronic or computer-based, in products and understand how these can be employed to achieve desired effects