dynamics and force weight density Flashcards
what is the nature of force?
it is the interaction betweeen 2 bodies that result in a push or a pull.
contact forces
applied forces
normal force
friction force
air resistance
buoyant force
tension force
spring force
hydrostatic force
non contact forces
gravitational force(weight)
electric force
magnetic force
what units are forces measured in?
N newtons
what is newtons 3rd law
RESTITUTION
“wheneever a force acts on a body, an equal and opposite force re-acts on the body that supplied the force.”
or more famously quoted
“ to every action, there is an equal and opposite reaction”
1) forces come in a _____
2) action and reaction pairs __ ___ act on the same object
3) action and reaction pairs are the same ____ of forces
1) pair
2) do not
3) type
how do forces, f, become resultant forces, F (free body diagram)
forces, f, added via vector addition the some of the forces the sum of the forces is called the resultant force, F
forces cause motion?
FALLACY forces DONT cause motion
forces cause motions to CHANGE
what is newtons 1st law
INERTIA,
“an object at rest will remain at rest, while an object at motion will remain in motion in a straight line unless compelled by a resultant force to do otherwise
is acceleration of an object the effect of F or f
F, resultant force as acceleration is the net force acting on an object.
not f, individual force
what is newtons 2nd law
ACCELERATION
“the rate of change of momentum of a body is proportional to the applied force and takes place in the direction in which the force acts”
or simply
“ for a constant mass, acceleration is directly proportional to force applied”
newtons 2nd law equation for force mass and acceleration
F =ma
2 types of friction
static frictions, friction when object at rest
dynamic friction, friction when object move
mass m definition
the amount of substance in a body
volume V definition
the amount of space occupied by a body
