Dynamics Flashcards
What is Newtons first law?
An object continues at rest of in uniform motion unless acted upon by a resultant force
What is Newtons second law?
The rate of change of momentum of an object is proportional to the resultant force on it, and takes place in the direction of that force.
What is Newtons third law?
When a body A exerts a froce on a body B, body B exerts an equal and opposite force on a body A.
What is the principle of conservation of momentum?
The total momentum of a system is constant provided no exertal forces act on the system
What is an elastic collison compared to an inelastic collision
An elastic collison has no kinetic energy lost or gained whereas in an inelastic collison, kinetic energy is lost.
What are the requirements for Newtons 3rd law?
- Act on different objects
- Same type of force (E.g gravitational)
- Acting in opposite directions
- Have the same magnitude
Explain how crumple zones save lives
Crumple zones increase the duration of the collision so the avergae force of the impact is reduced.
