Honolulu star-bulletin. [volume] (Honolulu [Oahu, Hawaii]) 1912-2010, 1916-11-04

sarI 70 enable him to care for 4
and repair any and all Of the Z
electrical features Of his car, no =
matter what make or model il =
' may be. =
= These articles are reproduced =
by permission from Motor Age, =
for which they have been pre- =
= pared BY David Penn Moreton =
and Darwin S. Hatch. =
+<t+<<< <<$<+<++ =
In general terms, a force is that
which produces. stops, changes OF
tends to produce. stop or change the
motion or rest OF a body. Thus. a
force always must be, applied 10 a
body to cause II TO move. as when you
push ON car, and force must be
applied in order to increase or de-
crease the velocity OF body that is
In motion. A force does not always
produce motion. but may only tend to
produce IL, as when you push on a
brick wall you apply muscular force,
but there is not necessarily any move.
nent Of the wall.
There are a number of different
kinds OF force, some OF the most com.
mon of which are as follows: Gravi.
rational force, as result of which all
bodies fall from higher to a lower
level; mechanical force, which may be
produced by the explosion of a gas
mixture in the cylinder OF the gas en-
CINE; electrical force, which produces
or tends to produce a movement of
electricity in the electrical circuit,
etc. The electrical force is commonly
produced by chemical action in the bat
terry or by means of an electrical
generator
An electrical force Is measured in
volts, while other forces are usually
measured in pounds.
IL a force overcomes q certain re-
sistance. work is done; or work is the
result Of the action of force through
certain distance. Work is measured
in unit which is a combination of the
unit in which the force is measured
and the unit in which the distance is
measured For example, If you push
on a car with a force OF rs pounds
and the car. moves through distance
Of 200 feet the work done will be
equal to the product of the value of
the force and the distance through
which the force acts, or 75X200=l5,-
200 foot-pounds
Work
Il must be clearly understood that a
force may exist without work being
done. as when you shove on a wall
you do not work unless there is an ac-
tual movement as a result of the
force.
II man carries 100 pounds OF ma
terial from one floor of building to
another floor which is so feet above
the one from which he started he will
do 100 times so or 5000 foot-pounds
OF work
A man would do the same amount Of
work in carrying 200 pounds of ma
terial up height OF % feet, so pounds
up a height of 100 feet. etc.
IF a pump raises 1900 gallons of
water vertical height of 100 feet and
each gallon weighs Is pounds, the
work done by the pump will be equal
TO the weight of the water raised null
tiplied by the distance through which
IL is raised The weight Of the water
Missed in this particular case is equal
Ito f200XS l-3=10,000 pounds. and
since this weight. of water is raised
100 feet the work will be equal to TO-.
600 x 100=1. 100000 foot-pounds.
The same amount Of work would be
done in raising 600 gallons to height
of 200 feet. 2400 gallons to height of
80 feet, etc.
A motor car weighing 5000 pounds
is to be raised from the ground floor
of a building by means of a freight
elevator to one Of the upper floors
which is SO feet above the ground
floor. Assuming that the elevator is
properly counterbalanced, and neg
lecting the friction of the guides. pull
leys, ropes. etc. what will be the
value Of the work done in raising the
car to the upper floor? The actual
work done in raising the car is equal
TO the weight OF the car multiplied
by the distance through which It is
raised. namely, 50oOx 5O=e5O.O 900 foot
pounds
Electricity at Work
The same amount of work would he
done in raising car weighing 5000
rounds a vertical distance of % feet
in raising one weighing 1900 pounds
vertical distance of 100 feet. etc.
disabled car is being drawn by
second car alta constant speed on a
level street and spring balance
which is connected in the tow rope
indicates a pull of 100 pounds The
work done in pulling the car a dis
lance of two miles is equal to the
distance in feet multiplied by the pull
on the car, or 2x52S0 Cor 1850 feet)
multiplied by 100, or 1.0j6.000 foot
sounds.
The same amount of work would be
done in drawing disabled car one
mile. If the pull on the tow rope were
200 pounds; in drawing a car four
miles. IL the pull on the tow rope were
so pounds. etc.
II a unit quantity of electricity, or
one coulomb, is moved from some
point on an electrical circuit to an
other point on the circuit whose cleo
trical pressure is one volt higher than