Zusammenfassung der Ressource
Newton's Laws
and Momentum
- Momentum and Impulse
- momentum = mass x velocity
- Momentum is always conserved
- total mu = total mv
- Even in inelastic collisions
- In elastic
collisions kinetic
energy is
conserved, it isn't
in inelastic ones
- Impulse is a change in momentum
- F = (mv-mu)/t
- Ft = mv - mu
- I.e. in crumple zones were t is increased F is decreased
- Newton's Laws
of Motion
- 1st Law - A force is needed to change velocity
- If the resultant forces aren't balanced, then
an object will accelerate
- 2nd Law - Force is the rate of change in momentum
(F=ma if the mass is unchanging)
- The resultant force is the vector sum of all forces and
acceleration is always in the same direction as the resultant force
- 3rd Law - If object A exerts a force on object B, then object B exerts an equal but opposite force on object B