INFO FROM ENERGY GRAPHS:
POTENTIAL ENERGY VS POSITION GRAPH
Value <-> potential energy
total energy - value <->
kinetic energy (since K+U = E)
Where U=E, kinetic energy is zero. Object is at a momentary
Where U<E, kinetic energy is positive. Object is
Where U>E, forbidden region. Object cannot be there
without being given more energy.
Slope <-> opposite of force
(F = -dU/dx)
Sloping up (such as / ) <-> force
is to left or toward smaller values of position.
example: gravitational potential energy
is sloping up everywhere, and the force is always toward smaller values
of height, i. e. down.
Sloping Down ( such as \ ) <->
force is to right or toward larger values of position.
example: for a compressed spring, potential
energy is sloping down, and the force is toward larger (less negative)
values of x.
Horizontal <-> no force (maybe
just for an instant)
If U=E at a point where the U curve is horizontal, then there
is no kinetic energy and there is no force. This corresponds to an
object at rest remaining at rest.