Momentum and Impulse

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 F=ΔpΔt 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