P3.1 - Objectives

• Can a two year hold girl hold a mass of 1kg for more than 2 minutes?

• Can you?

•Calculate the moment of a force with the correct units.•Describe the turning effect of a force on a force diagram.•Rearrange the moments equation to perform simple calculations.

d

F

Moment = Force x distanceM [newton metres] = F [newtons] x d [metres]

Here the turning moment is anti-clockwise so the beam turns anti-clockwise

F

For an object to be in equilibrium:Anti-Clockwise Moments = Clockwise Moments

OrAnti-Clockwise Moments - Clockwise Moments = 0

2F

Tasks• Make a Glossary in the first two pages of your books.

Write definitions of:– Pivot– Fulcrum– Load– Effort– Moment– Equilibrium– Clockwise– Perpendicular

• Write a couple of paragraphs explaining how and where levers are useful.

Ask yourself:

What is the purpose of this experiment?

Have I recorded any data?

Am I using my time wisely?

Complete Homework 2This can be found at

mrmathesonsphysics.wikispaces.com

If each red Lego piece has a downwards force of 1 unit, what will be the total moment of this system?

How could it be balanced?

Why don’t traffic cones fall over?

Using the equation of moments of a force - answers

1. a. Position ab. The moment is the same in each position, as it

always balances the anticlockwise moment.

2. 10 N × 2 m 2 N × 0.5 m – 35 N × 1 m –14 N m It will start to accelerate anticlockwise.

3.

StarterSort the pieces into three piles:

balancedclockwiseanti-clockwise

• Write definitions of:– Line of action– Stability– Base– Topple– Centre of mass