Mechanics 26 Lessons. An understanding of the principles in this unit and in the general requirements is expected in familiar and unfamiliar situations. In examination questions where the context is beyond the content of the specification it will be fully described. LESSON CONTENT RESOURCES LESSON NO: 1 - 4 TOPIC: Rectilinear motion 1-3 SYLLABUS STATEMENT Measure speed and Light gates, timers / data 1.1 Distance, displacement, 1-3 acceleration of trolley on logging computers, trolleys, speed, velocity and Experimental study of uniformly ramp using light gates ramps or use the acceleration. accelerated motion, based on laboratory (this will have been ultrasound motion sensor. Equations for uniformly measurements of displacement and covered at GCSE, but it ICT: P19: Weblinks: ‘Linear accelerated motion in one speed. will act as a good warm motion’ dimension. v = u + at up exercise). ICT: P19: Info sheet x = ut + ½at2 ‘Kinematics’ v2= u2+ 2ax Read pages 32 and 33 ICT: P19: Labmouse: ‘distance, displacement, ‘Kinematics’ speed, velocity and WS ‘Kinematic equation. acceleration’. ICT: Datalogging: ’Ball toss’ Questions (page 42) 2,3. ICT: Datalogging: ‘Determining g on an incline’ Derive the equations of ICT: Projector: Simulations: motion. acceleration. Read pages 36 and 37 ICT: Projector: Simulations: 4 ‘Equations of motion’ ‘The bouncing ball’ (for Measurement of the acceleration of free Questions (page 42) 7,9. resistance free motion) fall. A method involving a body in free 4 ICT: Projector: Simulations: fall is expected. Revise ideas about free ‘Mechanics – motion with fall from GCSE. Read constant acceleration’ pages 38 and 39 ‘ Vertical motion under gravity / terminal velocity’. Measure acceleration of a body in free fall to measure g. EXPT ‘Measuring g’ ICT: Datalogging: ‘Air Free-fall apparatus is resistance’ available. In addition students could use light gates, ticker timer or a stopclock and kinematics. LESSON NO: 5 - 8 TOPIC: Rectilinear motion LESSON CONTENT RESOURCES SYLLABUS STATEMENT 5+6 5+6 This section has again been quite well 1.2 Displacement-time and Identify and use the physical quantities covered at GCSE, you may wish to Note: Phillip Harris velocity – time graphs and derived from the gradient and area of progress to the experiment quite quickly ticker timers need carbon backed ticker their interpretation, for velocity – time graphs and the gradient of (and perhaps maintain a group of less tape. motion with uniform and displacement – time graphs. able students working on theory.) non- – uniform There is an excellent ICT simulation acceleration. for displacement and velocity time graphs. Read pages 34 + 35. Ramp, trolley, ticker Questions (page 42) 4, 5, 6 and 8. timer OR ICT: Ultrasound motion Record motion of a trolley on a ramp sensor to produce x/t using a ticker timer / motion sensor and and v/t graphs. convert into a displacement-time and velocity-time graph. The max speed, initial acceleration, distance-travelled etc. can then be calculated. 1.3 Projectiles 7+8 7+8 The independence of vertical and There are two good ICT demos ICT: Video camera horizontal motion should be understood. covering this topic. ICT: Projector: Numerical problems will involve either simulations: launch vertical or horizontal projection. A prebulit-launching device can be angle used to project 2 ball bearings, one vertically downward and the other with launching device. a horizontal velocity. ICT: Projector: simulations: ‘Projectile If possible the motion of falling objects motion’ with and without horizontal velocity can ICT: Projector: be filmed. Simulations: ‘Rocket’ Read pages 40 and 41. Questions (page 42) 10 and 11. LESSON NO: 9 - 12 TOPIC: Forces and motion LESSON CONTENT RESOURCES SYLLABUS STATEMENT 9 9 Much of this can be covered with a OHT ‘Basic forces’ 1.4 Forces interpreted as a Familiarity with gravitational, electric, reading homework: push or a pull and identified magnetic and nuclear forces; normal and Read pages 16 to 21 (not the WS ‘Understanding forces’ as the push or pull of A on frictional contact forces; viscous and drag passages on pressure or lift). Read B. forces; tension. page 24 on friction. Questions (page 25) 1,2,3 and 4. The gravitational pull of the Earth (or Moon, etc.) on an object. *Students can estimate and then Weight = mg measure the weight of familiar Variety of common objects objects. found in the lab. Newton meters. ICT: Projector: Simulations: 10 10 ‘Buoyforce’ 1.5 Free-body force diagrams. Use of free-body force diagrams to Read pages 22 and 23. ICT: P19: Weblinks: represent forces on a particle or on an The worksheet ‘Free-body force ‘Resultant forces’ extended but rigid body. Centre of diagrams’ provides practice that is WS ‘Free-body force gravity. lacking in the book. diagrams’ *Find the centre of gravity of an ICT:Info sheet: ‘Vectors and irregular object. forces’ Read page 29 on the centre of EXPT ‘finding the centre of gravity. gravity of an irregular object’ 11 + 12 ICT:P19: Weblinks: ‘Force’ 11 + 12 There are several good ICT 1.6 Newton’s first law. Bodies in equilibrium. Vector forces on resources for use here. ICT: P19: Labmouse: body sum to zero. Read pages 44 and 45 (not inertia). ‘Scalars and vectors’ OHT ‘Newton’s first law’ *The ‘three force equilibrium’ EXPT ‘Three force experiment should be set up before equilibrium’ class and results taken as a whole WS ‘Bodies in equilibrium’ group. It can be very time ICT: Projector: Simulations: consuming and complex if done in ‘Equilibrium’ pairs. ICT: Projector: Simulations: ‘Incplane’ The worksheet ‘Bodies in ICT: Projector: Simulations: equilibrium’ provides questions ’Resultant forces’ lacking in the text. LESSON NO: 13 - 15 TOPIC: Forces and motion LESSON CONTENT RESOURCES SYLLABUS STATEMENT 13 13 This topic has been covered at 4 x OHTs ‘Newton’s 1.7 Newton’s third law. Force pairs. A statement that the push or GCSE and hence may be mostly third law’ pull of A on B is always equal and covered with a reading opposite to the push or pull of B on A. homework: Read pages 48 and 49. Question (page 59) 7. There are a few fun experiments EXPT ‘Force pairs that can be tried. experiments’ 14 + 15 14 + 15 ICT: P19: Weblinks: 1.8 Moment of a force. Moment of F about O = Note moments and the principle ‘Moments’ F x (perpendicular distance from F to O). of moments is now only in Key ICT: P19: Infosheet: stage 3!. It may have been some ‘Moments’ Principle of moments. For a rigid body in equilibrium, sum of time since the students have ICT: Projector: clockwise moments about any point = used these concepts. Simulations: ‘Lever’ sum of anticlockwise moments about that point. *Principle of moments Problems will only be set involving sets experiment. of parallel forces. There is a good ICT simulation EXPT ‘Principle of on this topic. moments’ Read pages 26 to 30 Questions (page 21) 1 to 8. ICT Physim4: mechanics: lever There are two good worksheets principle. on this topic. WS ‘Just a moment’ WS ‘Harder moments’ LESSON NO: 16 + 17 TOPIC: Forces and motion LESSON CONTENT RESOURCES SYLLABUS STATEMENT 16 + 17 16 The students may not have Polystyrene and 1.9 Density. Typical values for solids, liquids and come across the concept of metal blocks of the gases. Measurement of the density of density previously. same mass. solids, liquids and gases is expected. Introduce with polystyrene and Application of = m/V metal blocks of the same mass. Read page 288. Question (page 295) 9. EXPT ’Measuring Students measure density of the density of air’ solids, liquids and air (see expt WS ‘Density’ details. Density worksheet. *Students find out the densities of the Earth, the sun and an atomic nucleus. Bottle of mercury. Students feel mass of a bottle of mercury (SAFETY : ‘Ensure that it is lifted only a small distance above a tray) LESSON NO: 18 - 20 TOPIC: Dynamics SYLLABUS STATEMENT LESSON CONTENT RESOURCES 18 - 20 18 - 20 OHT ‘Momentum’ 1.10 Linear momentum. Defined as p = mv ICT: P19: Weblinks: Principle of the Experimental study of conservation of ‘Momentum’ conservation of linear linear momentum for collisions in one Read page 46 for linear ICT: P19: Info momentum dimension only. momentum. sheet: ‘Momentum’ Question (page 58) 2. Read pages 54 and 55 for ICT: Projector: conservation of momentum, Simulations:’Collisio Question (page 59) 14, 15, 16, ns’ 17 and 18. ICT: Projector: Simulations:'Mecha nics: elastic and inelastic collisions’ *Experiment / demo collisions on EXPT ‘Air track air track to investigate principle collisions’ of conservation of momentum. ICT: Datalogging: ‘Momentum, Measure speed of pellet from air energy’. rifle. EXPT ‘Speed of pellet’ Demonstrate Newton’s cradle. Newton’s cradle. LESSON NO: 19 - 26 TOPIC: Dynamics LESSON CONTENT RESOURCES SYLLABUS STATEMENT 19 + 20 19 + 20 Read pages 52 and 53. EXPT? collision 1.11 Newton’s second law. Force and rate of change of momentum. Questions (page 59) 11, 12 and with timer??? Resultant force as rate of change of 13. momentum F = p/t OHT ‘Momentum Calculations will only be set in situations and impulse’ where mass is constant. Impulse = change of momentum. ICT: P19: Infosheet ‘ Newton’s law’ ICT : Datalogging: ‘Impulse and momentum’ ICT: Projector: Simulations:'n2law’ ICT: Projector: simulations: ‘Newton’s cradle’ 21, 22 and 23 21, 22 and 23 1.12 Acceleration, mass and Applications of F = ma Investigation force. Experimental investigation of uniformly *Students investigate the accelerated motion where mass is relationship between F, m and a EXPT ‘Newton’s constant. using air tracks or friction second law’ compensated motion ramps and OHT ‘Newton’s light gates. second law’ 24 Revise for test (see revision questions). Read pages 46 and 47. Questions (page 58) 1, 3, 4, 5, 9, 10 (a + c), 11, 13. 25 Mechanics test Read pages 56 and 57 on car safety. 26 Revision Questions: Page 104: Go through test. 7, 7(a), 9, 10, 11, 12, 13, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35.