9.1 Momentum And Impulse Flashcards
What did newton realise was needed to change the velocity of an object
A force
What is momentum defined as
The mass of the object x velocity
When do newtons laws not apply
Inside an atom where the rules of quantum physics apply
In strong gravitational fields where Einsteins theories of relativity apply
Momentum =
mass x velocity
Symbol for momentum
P
What quantity is momentum
Vector
The direction is the same as the direction of the objects velocity
Newton’s first law
An object remains at rest or in uniform motion unless acted on by a force
If an objects momentum is constant what is the resultant force acting on it
There js no resultant force
what happens if a moving object with constant momentum gains or loses mass
the velocity would change to keep the momentum constant
newtons second law of motion
the rate of change of momentum of an object is proportional tot he resultant force on it
in other words the resultant force is proportional to the change of momentum per second
F=ma
force =
change in momentum / time taken
mv - mu / t
if m is constant what is done for the force equation
its just the change of the velocity
what to do if m changes at a constant rate at a constant velocity
v change in m/time taken
impulse =
force delta t = change in mv
what is the impulse of a force acting on an object equal to
the change of momentum of an object
what is the area under a force time graph
represents the change of momentum or the impulse of the force
units momentum and impulse are given in
momentum = Ns or kg/ms
impulse = Ns
