DP Physics (last assessment 2024)
Syllabus sections »

2.4 – Momentum and impulse

Description

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. (1.9)

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

Guidance:

  • Students should be aware that F = ma is equivalent of  only when mass is constant
  • Solving simultaneous equations involving conservation of momentum and energy in collisions will not be required
  • Calculations relating to collisions and explosions will be restricted to one-dimensional situations
  • A comparison between energy involved in inelastic collisions (in which kinetic energy is not conserved) and the conservation of (total) energy should be made

Data booklet reference:

International-mindedness:

  • Automobile passive safety standards have been adopted across the globe based on research conducted in many countries

Theory of knowledge:

  • Do conservation laws restrict or enable further development in physics?

Utilization:

  • Jet engines and rockets

Martial arts

  • Particle theory and collisions (see Physics sub-topic 3.1)

Aims:

  • Aim 3: conservation laws in science disciplines have played a major role in outlining the limits within which scientific theories are developed
  • Aim 6: experiments could include (but are not limited to): analysis of collisions with respect to energy transfer; impulse investigations to determine velocity, force, time, or mass; determination of amount of transformed energy in inelastic collisions
  • Aim 7: technology has allowed for more accurate and precise measurements of force and momentum, including video analysis of real-life collisions and modelling/simulations of molecular collisions

 

 

Directly related questions

Sub sections and their related questions

None