What you’ll learn12 learning objectivesChoose one objective for a focused lesson, or study the complete topic.1.5.1.1Forces may produce changes in the size• Know: forces may produce changes in the size and shape of an objectSyllabus objective1.5.1.2Load–extension graphs for an elastic• Sketch, plot and interpret load–extension graphs for an elastic solid and describe the associated experimental proceduresSyllabus objective1.5.1.3Resultant of two or more forces acting• Determine the resultant of two or more forces acting along the same straight lineSyllabus objective1.5.1.4An object either remains at rest or• Know: an object either remains at rest or continues in a straight line at constant speed unless acted on by a resultant forceSyllabus objective1.5.1.5A resultant force may change the• State: a resultant force may change the velocity of an object by changing its direction of motion or its speedSyllabus objective1.5.1.6Solid friction as the force between• Describe solid friction as the force between two surfaces that may impede motion and produce heatingSyllabus objective1.5.1.7Friction (drag) acts on an object• Know: friction (drag) acts on an object moving through a liquidSyllabus objective1.5.1.8Friction (drag) acts on an object• Know: friction (drag) acts on an object moving through a gas (e.g. air resistance)Syllabus objective1.5.1.9Spring constant as force per unit• Define spring constant as force per unit extension; recall/use: k = F/xSyllabus objective1.5.1.10Term ‘limit of proportionality’ for a• Define and use the term ‘limit of proportionality’ for a load–extension graph and identify this point on the graph (an understanding of the elastic limit is not required)Syllabus objective1.5.1.11Recall/use: F = ma• Recall/use: F = ma; know: the force and the acceleration are in the same directionSyllabus objective1.5.1.12Circular motion caused by a force• Describe circular motion caused by a force perpendicular to motion: (a) greater force increases speed if mass/radius stay constant (b) greater force decreases radius if mass/speed stay constant (c) greater mass needs greater force to keep speed/radius constant (F = mv^2/r not required)Syllabus objective