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What did you learn last time?. 1 thing you learnt from last lesson 1 question you had from last lesson that wasn’t answered High 5. 10 June 2014. Principle of moments. Objectives Be able to define and use the principle of moments . OUTCOMES. ALL Be able to define the principle of moments
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What did you learn last time? • 1 thing you learnt from last lesson • 1 question you had from last lesson that wasn’t answered • High 5
10 June 2014 Principle of moments Objectives Be able to define and use the principle of moments
OUTCOMES • ALL • Be able to define the principle of moments • MOST • Be able to apply the principle of moments to different situations • SOME • Be able to apply the principle of moments to problems with more than 2 forces
Principle of Moments Total anticlockwise moment Total clockwise moment =
Is this Balanced? • Example 1 (of 3) • Explain how you know if it is or not (using maths to describe) 50 cm 90 cm x cm 10 N 8 N
20 N 90 cm 50 cm x cm 10 N 12 N Example 2 (of 3) Take moments about the pivot to find the distance x. (system is obeying principle of moments)
Example 3 (slightly harder) Given that the system is balanced; take the clockwise and anticlockwise moments about the pivot to find the force X. 10N 5N 8N 5N 5cm 20cm 60cm 5cm 85cm 10cm 10N XN Careful, Answer not necessarily a whole number extension
Summary • Review vid: http://www.youtube.com/watch?feature=player_embedded&v=WclR1jR0kdk