Linear Motion Kinematics Circular Kinematics Forces & Linear Motion Friction Forces Work & Energy
Work and Energy
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Work
and Energy
Work:
W
= Fd,
where F
is the force doing work on an object and d
is the distance the object moves in the direction of the force.
Kinetic
energy, the energy an object possess because of its motion: KE
= 1/2
m v2,
where m
is the mass of the object and v
is its linear speed. When work is done on an object, the increase in its
kinetic energy equals the work done by all the forces acting on it.
Potential
energy due to gravity,
the energy an object possesses because of its location above some
reference point: PE
= m g
h, where m is the mass of an object, h is its height or distance above
a reference point, and g
is the constant 9.8 m/s2.
Potential
energy of an elastic
material: when a springy object such as a diving board or floor mat is
deformed, it possesses potential energy which depends on the amount of
deformation.
Energy Conservation: If there are no energy losses due to friction, the
sum of these three kinds of energy for an object is constant.