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Technical Terms (part 1)
inertia
The force that causes an object
to remain stationary unless it is acted on by some external
force. Once an object is in motion, inertia is the force
that causes it to stay in motion until it is acted on by
an external force.
work
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The act of moving an object from one position to
another. Work equals the force (in pounds) that is
required to move an object multiplied by the distance
the object is moved (in feet).
Work = Force x Distance
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How much
work is performed to move a 5 lb. block 3 ft.?
Work = 3ft. x 5 lbs = 15 ft. lbs. |
Power
The speed at which work is performed.
One horsepower is defined as performing 33,000 ft lb of
work in one minute.
energy
The capacity to do work. There are
two types of energy. Potential energy (PE) is the energy
of an object at rest. Kinetic energy (KE) is the energy
of a moving object at its current velocity.
PE = M
x A x H
KE = 1/2 x M x V |
M = object mass
A = acceleration of gravity = 32.2 ft/sec²
H = height of the object above the ground
V = object velocity |
torque
The turning or twisting force exerted
on an object. Torque differs from work or power in that
it doesn't always produce motion.
friction
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The resistance between two
bodies that contact each other (or that are separated
only by lubricants). The quotient of dividing the
force required to slide one object over another at
a constant speed by the pressure holding them together
is a constant, and it is known as the coefficient
of friction. This value is always the same for the
given materials and surfaces.
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Example
for determining the coefficient of friction.
COF = 20/60 = 0.333 |
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