Explain how levers are used in spanner. Ask students why the things have a tin of weighted end to common devices. are made in different sizes and ask paint and five demonstrate State what is meant by a moment of a them to suggest situations in which different that, when force and recall its units. they would use the large or the small of working out a Recall that an object will balance if the example. different lengths moment, the moments are equal and opposite. (5 cm, 10 cm, 15 distance used Describe the factors that affect the size Exploring: Using levers cm, 20 cm and must be of a moment. Set up a circus and allow students to 25 cm). Ask them perpendicular to Securing try different levers. Ask students to to write down the force. Identify the pivot, load and effort in identify the pivot and the position of which Class 2 and Class 3 levers. the effort. they would Use the formula relating moment, choose and why, force and perpendicular distance. Explaining: Perpendicular distances using as much Exceeding Use a long object with a weighted end physics as they Describe how gears affect the force to demonstrate that, when working can in their needed to move an object and the out a moment, the distance used answers, speed of movement. must be perpendicular to the force. including the Explain how gears work using ideas Calculate what the moment of the words ‘pivot’, about moments. weight. ‘load’ and ‘effort’. Plenary: Thinking about levers Consider All Possibilities: You cannot lift a heavy mass using a lever. (Possible answers: the mass is too far away from the fulcrum; the lever is not long enough; you cannot provide enough force.) Lesson 9Ie: More machines Learning objectives Exemplar teaching activities Differentiation Resources Maths skills Practical skills Developing Starter: Sure or unsure? Exploring: Resources Substitute Students Describe how a ramp or a simple Ask students to write down one thing Investigating from 9Ie into investigate the pulley system can reduce the force about levers and moments that they pulleys Exploring formulae. force needed to needed to lift an object. are sure about, and one thing they Ask students to Science. lift a given Recall that if the force needed is are unsure about. Revise the things calculate the mass with decreased the distance it moves is that students are having difficulty work done in different
Explain how levers are used in common devices. State what is meant by a moment of a force and recall its units. Recall that an object will balance if the moments are equal and opposite. Describe the factors that affect the size of a moment. Securing Identify the pivot, load and effort in Class 2 and Class 3 levers. Use the formula relating moment, force and perpendicular distance. Exceeding Describe how gears affect the force needed to move an object and the speed of movement. Explain how gears work using ideas about moments. spanner. Ask students why the things are made in different sizes and ask them to suggest situations in which they would use the large or the small example. Exploring: Using levers Set up a circus and allow students to try different levers. Ask students to identify the pivot and the position of the effort. Explaining: Perpendicular distances Use a long object with a weighted end to demonstrate that, when working out a moment, the distance used must be perpendicular to the force. Calculate what the moment of the weight. Plenary: Thinking about levers Consider All Possibilities: You cannot lift a heavy mass using a lever. (Possible answers: the mass is too far away from the fulcrum; the lever is not long enough; you cannot provide enough force.) have a tin of paint and five different of different lengths (5 cm, 10 cm, 15 cm, 20 cm and 25 cm). Ask them to write down which they would choose and why, using as much physics as they can in their answers, including the words ‘pivot’, ‘load’ and ‘effort’. weighted end to demonstrate that, when working out a moment, the distance used must be perpendicular to the force. Lesson 9Ie: More machines Learning objectives Exemplar teaching activities Differentiation Resources Maths skills Practical skills Developing Describe how a ramp or a simple pulley system can reduce the force needed to lift an object. Recall that if the force needed is decreased the distance it moves is Starter: Sure or unsure? Ask students to write down one thing about levers and moments that they are sure about, and one thing they are unsure about. Revise the things that students are having difficulty Exploring: Investigating pulleys Ask students to calculate the work done in Resources from 9Ie Exploring Science. Substitute into formulae. Students investigate the force needed to lift a given mass with different
Physics2years.docx