The conservation of momentum theorem with Cobra DigiCart

Principle

The momentum of a moving body is defined as the product of its mass and its velocity.

Newton's second law states that the change in momentum over time corresponds to the external force acting.

Conversely, this means that a change in momentum can be calculated as a time integral over the acting force.

The total momentum of a system is thus obtained exactly when no external forces are acting. The total impulse is constant at any time. In the following two different impact variants are presented. An impact is a physical process in which two or more bodies briefly exert force on each other.

Elastic impact: In this form of impact, two bodies meet without energy being converted into heat or deformation. The energy in this impact therefore remains constant.

Inelastic impact: In this form of impact, two bodies meet, whereby energy is converted into heat or deformation. The energy in this impact is therefore not constant.

Benefits

• Free measuring software DigiCartAPP for all mobile devices and all operating systems (Windows, Android, iOS).
• Especially understandable and didactically prepared experimental literature can be used in the DigiCartAPP.
• Complete evaluation function for the measured data directly in the DigiCartAPP.
• DigiCart:
  • Long-life lithium-ion batteries with charge protection function
  • Transmission of measurement data via Bluetooth 4.0
  • Integrated sensors (force, speed, acceleration and position sensor)
• Digital measured value acquisition:
  • Future-oriented teaching: Integration into digital science lessons with tablets or smartphones.
  • Increased student motivation by using the intuitive DigiCartAPP.
  • Increase of media competence.

Tasks

1) Perform an elastic shock with the two DigiCart Analyse the change in momentum and energy of the system before and after the impact.

2) Perform an inelastic impact with the two DigiCart. Analyze the change in momentum and energy of the system before and after the impact.

Learning objectives

• physical concept
• energy conservation
• elastic/inelastic impact