2. Mechanics
2. Mechanics
2.1 – Motion
Nature of science:
Observations: The ideas of motion are fundamental to many areas of physics, providing a link to the consideration of forces and their implication. The kinematic equations for uniform acceleration were developed through careful observations of the natural world.
Understandings:
Distance and displacement
Speed and velocity
Acceleration
Graphs describing motion
Equations of motion for uniform acceleration
Projectile motion
Fluid resistance and terminal speed
Applications and skills:
Determining instantaneous and average values for velocity, speed and acceleration
Solving problems using equations of motion for uniform acceleration
Sketching and interpreting motion graphs
Determining the acceleration of free-fall experimentally
Analysing projectile motion, including the resolution of vertical and horizontal components of acceleration, velocity and displacement
Qualitatively describing the effect of fluid resistance on falling objects or projectiles, including reaching terminal speed
2.2 – Forces
Nature of science:
Using mathematics: Isaac Newton provided the basis for much of our understanding of forces and motion by formalizing the previous work of scientists through the application of mathematics by inventing calculus to assist with this. Intuition: The tale of the falling apple describes simply one of the many flashes of intuition that went into the publication of Philosophiæ Naturalis Principia Mathematica in 1687.
Understandings:
Objects as point particles
Free-body diagrams
Translational equilibrium
Newton’s laws of motion
Solid friction
Applications and skills:
Representing forces as vectors
Sketching and interpreting free-body diagrams
Describing the consequences of Newton’s first law for translational equilibrium
Using Newton’s second law quantitatively and qualitatively
Identifying force pairs in the context of Newton’s third law
Solving problems involving forces and determining resultant force
Describing solid friction (static and dynamic) by coefficients of friction
2.3 – Work, energy and power
Nature of science:
Theories: Many phenomena can be fundamentally understood through application of the theory of conservation of energy. Over time, scientists have utilized this theory both to explain natural phenomena and, more importantly, to predict the outcome of previously unknown interactions. The concept of energy has evolved as a result of recognition of the relationship between mass and energy.
Understandings:
Kinetic energy
Gravitational potential energy
Elastic potential energy
Work done as energy transfer
Power as rate of energy transfer
Principle of conservation of energy
Efficiency
Applications and skills:
Discussing the conservation of total energy within energy transformations
Sketching and interpreting force–distance graphs
Determining work done including cases where a resistive force acts
Solving problems involving power
Quantitatively describing efficiency in energy transfers
2.4 – Momentum and impulse
Nature of science:
The concept of momentum and the principle of momentum conservation can be used to analyse and predict the outcome of a wide range of physical interactions, from macroscopic motion to microscopic collisions.
Understandings:
Newton’s second law expressed in terms of rate of change of momentum
Impulse and force–time graphs
Conservation of linear momentum
Elastic collisions, inelastic collisions and explosions
Applications and skills:
Applying conservation of momentum in simple isolated systems including (but not limited to) collisions, explosions, or water jets
Using Newton’s second law quantitatively and qualitatively in cases where mass is not constant
Sketching and interpreting force–time graphs
Determining impulse in various contexts including (but not limited to) car safety and sports
Qualitatively and quantitatively comparing situations involving elastic collisions, inelastic collisions and explosions
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