General Mechanics/Force and Motion

Year 10	Force and Work	7 periods •**Reinforce ideas about force causing acceleration (= the rate at which speed changes)
 * Possible Approach:
 * Lesson	Suggested Learning Outcomes	Course Outline	Resources
 * 1 – 3 		Recognise that unbalanced forces cause acceleration.
 * 	Investigate the relationship between the unbalanced force acting on an object, is mass *and acceleration: Newton’s Second Law. (Use Fnet = ma giving correct units for all quantities)
 * Experiment 1: Finding the force required to move an object (static friction)
 * Discuss the factors that may affect the frictional forces acting on the block (e.g. load on *the block, surface area in contact with the bench, type of the surfaces in contact …)
 * Attach a force meter to a block at rest on the bench. Pull the force meter and slowly increase *the force until the block just begins to move – record the force meter reading, tabulate data, *repeat, calculate average.
 * [Or, use a bag to which washers may be added, attached to a cord and hanging over the end of *the bench to pull the block.]
 * quantities and the third unknown) – a three symbol triangle may simplify the maths.
 * Homework:	Coursebook – Newton’s second Law
 * force (e.g. when a force acts on a body, it moves faster and kinetic energy increases)
 * •	Introduce the relationship between energy transferred and work done.
 * •	Define work done in terms of the applied force and the distance through which this ********force acts (Work done = force x distance)
 * •	Introduce the relationship between energy transferred and work done.
 * •	Define work done in terms of the applied force and the distance through which this ********force acts (Work done = force x distance)


 * •	Use the work rule to calculate work / force / distance (given two quantities and the ********third unknown) – a three symbol triangle may simplify the maths


 * Homework:	Coursebook – Work Done and Energy


 * 6 – 7  		Investigate and describe the pattern of results formed from graphing ************************the effects of applied forces on a spring.


 * Explore the relationships between science and technology by investigating the application of *science to technology and the impact of technology on science, e.g. Archimedes’ screw to *illustrate the principle of oits use in water irrigation or the use of springs and similar *propulsion devices in toys
 * Experiment 4: Stretching Springs
 * Hang a spring vertically using a clamp and stand. Add weights to the end of the spring, *measure the length of the spring after each additional weight is added. Calculate the *extension (Note: some initial weight will probably need to be added before the spring *stretches at all) Graph extension vs applied force. Interpret the graph, e.g. find the *extension for unit applied force or applied force per unit extension.
 * Hang a spring vertically using a clamp and stand. Add weights to the end of the spring, *measure the length of the spring after each additional weight is added. Calculate the *extension (Note: some initial weight will probably need to be added before the spring *stretches at all) Graph extension vs applied force. Interpret the graph, e.g. find the *extension for unit applied force or applied force per unit extension.
 * Hang a spring vertically using a clamp and stand. Add weights to the end of the spring, *measure the length of the spring after each additional weight is added. Calculate the *extension (Note: some initial weight will probably need to be added before the spring *stretches at all) Graph extension vs applied force. Interpret the graph, e.g. find the *extension for unit applied force or applied force per unit extension.


 * Investigate and understand the turning effect of a force.
 * Calculate the turning effect of a force = F x d where force (F) and distance (d) are *********at right angles.
 * Use the lever rule:   F1d1   =  F2d2 	•


 * Discuss and brainstorm ideas about what causes things to turn about a pivot (fulcrum).
 * •	Introduce the concept of the turning effect of a force (torque).
 * •	Discuss the concept levers – to increase the turning effect, use a greater distance *******(e.g. a long crowbar) and/or a greater force (e.g. a heavier weight)
 * •	Use the lever rule to calculate forces and distances at right angles to the applied ********force (given three quantities and the fourth unknown).
 * Experiment 5: The turning effect of a force
 * Kit available from the science Office
 * •	Homework:	Coursebook – The Turning Effect of a Force
 * Extension
 * Extension