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. (1.8)

• 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

• International cooperation is needed for tracking shipping, land-based transport, aircraft and objects in space

Theory of knowledge:

• The independence of horizontal and vertical motion in projectile motion seems to be counter-intuitive. How do scientists work around their intuitions? How do scientists make use of their intuitions?

Utilization:

• Diving, parachuting and similar activities where fluid resistance affects motion
• The accurate use of ballistics requires careful analysis
• Biomechanics (see Sports, exercise and health science SL sub-topic 4.3)
• Quadratic functions (see Mathematics HL sub-topic 2.6; Mathematics SL

sub-topic 2.4; Mathematical studies SL sub-topic 6.3)

• The kinematic equations are treated in calculus form in Mathematics HL sub-topic 6.6 and Mathematics SL sub-topic 6.6

• Calculations will be restricted to those neglecting air resistance
• Projectile motion will only involve problems using a constant value of g close to the surface of the Earth
• The equation of the path of a projectile will not be required

Data booklet reference:

• Aim 2: much of the development of classical physics has been built on the advances in kinematics
• Aim 6: experiments, including use of data logging, could include (but are not limited to): determination of g, estimating speed using travel timetables, analysing projectile motion, and investigating motion through a fluid
• Aim 7: technology has allowed for more accurate and precise measurements of motion, including video analysis of real-life projectiles and modelling/ simulations of terminal velocity