physics Flashcards
Newton’s first law of motion
An object at rest will stay at rest until acted up by an external force (vice versa)
Inertia
Objects ability to esist changes in motion
Net force
when more than a single force acts on an object (shown by arrows
vector quantity
force that has both magnitude and direction
Scalar quantity
only magnitude (no direction)
Mechanical Equilibrium
Net force is equal to zero
support force
aka normal force, the upward force opposite to gravity. ex a book on a table in equilibrum
Dynamic Equilibrium
an object moving i constant speed in a straightline path is also in equalibrium , state of no change. has 2+ forces acting on it
linear motion
motion in a straight line
-speed
speed
distance over time, ex mph
instantaneous speed
speed at any instant in time
average speed
total distance covered/ time interval
velocity
how fast and what direction (vector quantity)
constant velocity
motion in a straight line (direction) (no curves) at a constant speed
changing velocity
either speed or direction change
acceleration
how quick velocity changes (ex 0 to 60 in 2 seconds), has to include time.
depends on net force
acceleration
applies to increases nad decreases in velocity, applies to curves also bc direction is changing
free fall
only under influence of gravity. the acceleration is 10 mters per sec each sec
velocity of a falling object on earth equation
free fall
v=gt
Newtons second law
the acceleration of an object is directly proportional to the net force acting on the object and is inversely proportional to the mass of an object
(greater the mass the greater the inertia)
friction
force produced when surfaces slide over one another (usually reducing net force and acceleration)
not dependent on speed, or the area of contact
mass and voume: are they equal?
think the box filled with nuts and bolts vs empty box
same volume but diff mass
newtons 3rd law
motion and vectors. for every action theres an equal and opposite reaction
lift
when lift equals weight of object it will hover, but when lift is greater it will rise
adding vetors along a parallel
if they act in same direction they add
opposite directions, subtract
