Newtons First Law
What is net force the sum of?
the sum of all the forces acting on an object
what is a vector?
a quantity including direction and magnitude
for every action force there exists an equal and what reaction force?
opposite reaction force
how many types of friction are there?
two main types
when forces are balanced is there a change in direction?
no
a non zero net force will change what?
the velocity
the greater the force the greater the what?
acceleration
force always come in ______?
pairs
what is static friction?
static friction keeps a stationary object at rest
typically are the two forces acting upon an object the same size or unequal, when the forces are unbalences?
unequal sizes
what forces change the motion?
external forces
the greater the mass the smaller the what?
acceleration
if there is a reaction you know there is an?
equal and opposite action
what is kinetic friction?
kinetic friction is what slows down an object in motion
if an object is as rest is it acted upon an unbalanced or balanced force?
balanced
if the net force is zero the objects velocity will remain?
unchanged
the net force acting on an object is equal to the product of its acceleration and what?
mass
If car tires grab the road and push backwards, what is the roads reaction?
the road will push the car forward.
is friction between joints wanted or unwanted?
unwanted causes pain!
is tug of war between you and your little brother an example of balanced or unbalanced forces
unbalanced forces
if an object is stationary it must have no external forces acting on it? T or F
FAlse
an object will accelerate in the direction of the what force?
net force
what is inertia?
an objects resistance to a change in motion
kinetic friction is either what or what friction?
sliding or rolling
force has both direction and what?
strength