4' Work, energy, power

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4.Work, energy, power

• Kamil Sarka

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Impulse of the force
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The effect of the force on the path
WORK
http//www.glenbrook.k12.il.us/gbssci/phys/Class/e
nergy/u5l1a.html http//www.glenbrook.k12.il.us/gb
ssci/phys/Class/energy/u5l1aa.html
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Work is energy
Energy is the capacity for doing work. You must
have energy to accomplish work - it is like the
"currency" for performing work.
ENERGY Heat Mechanical Electrical Chemical
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Mechanical energy
work which can be done by means of change of
the machanical state of the body
1. Change of velocity gt kinetic energy
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Mechanical energy
work which can be done by means of change of
the machanical state of the body
2. Change of position gt potential energy
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The law of conservation of energy
The sum of energies before and after is the same
example sum of kinetic and potential energy
during the movement
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Power
is the rate of doing work or the rate of using
energy, which are numerically the same.
Efficiency the rate of energy beeing consumed
by the system
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Point mass systemrigid bodies
Rigid not deformable
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Pair of opposing forces
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Equilibrium conditions
Point mass
Rigid body
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If
(second Newtons law)
A, if
total mass of the body
Center of gravity
http//www.grc.nasa.gov/WWW/K-12/airplane/cg.html
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If
(second Newtons law)
B, if
Distance from the center of mass
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Thank you.