Transcript Newton’s 2nd Law

Newton’s
nd
2
Law
If
balanced forces
means no acceleration,
unbalanced forces means
acceleration
A
net force causes a
mass to accelerate.
Relationship between net force
and acceleration
Fnet  a
Relationship between mass and
acceleration
1
m
a
Fnet = ma
Net Force =
mass x
acceleration
Solving Problems
1.
2.
3.
Identify the forces acting
on the object.
Determine the net force
or an expression for it.
nd
Apply Newton’s 2 Law.
Friction
A
force between two
surfaces.
Parallel to the surfaces
Acts in a direction to
oppose motion
Friction cont’d
Directly
proportional to the
force pressing the surfaces
together (normal force)
Proportional to the type of
surfaces (coefficient of
friction)
Ff=mFn
Friction =
(coefficient of
friction) x (normal
force)
Two kinds of friction
Static
friction (ms)object is not moving
Sliding (kinetic) friction
(mk)-object is moving
 ms>mk