1. Tasks: Mane, 19 Whiringa-ā-nuku 2015 1)Finish Wednesday’s worksheet 2)Activity 9A 3)H/W Set 5 separating blood/plasma oil cleaning pilot training watch Jeremy Clarkson (4 min) Application : centrifuges

2. Torque Torque is the turning effect of a “force couple” acting around the centre of mass Symbol:  Measured in Nm Vector: acts clockwise or anticlockwise Force and distance from pivot must be perpendicular r F ► Does this cause pure rotation? NO axle reaction force means no net translational motion pure rotation results

3. Example: The diagram shows the rear gear wheels on a mountain bike. The rider pushes with a force of 200N when the chain is on the largest gear wheel, which has radius 7.0cm a)Calculate the torque the chain applies to the rear wheel b) Calculate the force needed to apply the same torque when the rider changes gear and the chain is shifted to the smallest gear wheel, which has radius 3.0cm