Richmond enquirer. [volume] (Richmond, Va.) 1815-1867, 1817-11-25
An,uc,. 10 the Cnr;ons, ProLIc,n.
no rHE EpIroR on rng ENQuIREl

SIR fla steam boat can be propelled five
miles per hour by the steam orwiud when
acting separately, will the velocity of the boat
be increased by both of these powers acting
on the hoat at the same timeY The following
answer To this question is plainly demonstra-
bic II ON the laws of motion. When the area
Ola sail is given, the momentum with which
tie wind will strike tIiv SAIL will he as the
square of the velocity. The momentum is, as
the quantity of matter, and velocity conf ointly
hut the quantity of matter, is as the veioci-
~ for tie qnicker, or slower the wind moves,
the more or fewer particles strike against "A
given surface, IN given time. The momcn-
tuin will there tore he as the square ofthe We
Iocity. The momentum of the wind TO move
sail, when it blows with given velocity, will
always be as the square ct Tie au.ie OF Incl
dcnce. or the angle between The direction of
the wilma, and the perpendicular TO The surface
OF the sail. A wind that blows with double the
velocity ofanother wind, will give four times
the momentum to given sail, to move the YES
SET: For instance ii the wind with n velOci-
~ OF ~ miles per hour, strikes the sail with a
momentum equsi 10 10, and the velocity of a
mother wind is 40 mites per hour. it will strike
the sail with a momentum OF 81, which is
tunes 10: the momentum of the first wind he
ing 10 IL rs plain ii the wind blows with the
velocity Of 10 miles per hour, and strikes tie
SAIL with TIE momentum of lC; and the vcloci-
~ OF the vessel IS . miles pei hour half of the
velocity ct the wind, as il respects the vessel
sIost the momentum pressing on fIIe sail
will he consequently reduced from 10 TOD
The velocity of the paddles will increase AZ
the resistance decreases, but the force or mo.
mentum will not increase. When "A given
power is applied TO the paddles, there will al
ways be the same ratio between tile velocity of
tie paddles, and the velocity of the stream;
say stream, for action and reaction are co,,al
for if the b0at he forced at the rate of miles
per hour IN still water, the action of the boat
on the water, will create a current of . miles
pcrhour on each side, which will strike the
boat with the same force or momentum as if
red N
rent was five miles per hour therefore tie
paddles gain no torce by the gain OF velocity.
forthe velocity OF The stream increases in the
same ratio of course the steam will propei
the boat miles per hour, and no more. rhe
wind has 10 propel the whole boat, or over
come the whole of the resistance, after the
boat exceeds the velocity OF miles per hour,
given by the steam but then, the velocity of
the wind is reduced one half; the resistance
is not decreased after the velocity offs miles
per hour given by the steam OF course the
momentum with which the wind strikes tile
sail is reduced to one fourth that is il is redu-
ceh from 10 to 4. If a momentum OF 4 would
carry body over given space in given
time halt that momentum would carry il
over hall of that space; third of the momen-
tum would carry il oyera third of the space
and fourth OF the momentum would carry il
over a fourth of the space, in the same ratio
The wind would therefore carry the boat when
acting with the steam one fourth of the dis
lance that IL would carry the boat in the same
miles, which is nile and 40 yards: which
added To miles, the eiocity with which rhe
steam propels the boat, make the velocity q
miles, aud 40 yards per hour, when the steam
and wind ACT upon the boat at the same time
But suppose the velocity of the wind is 20
miles per hour, and the wind strikes the sail
with momentum of 400 4: as soon as the steam
gives velocity TO the boat at the rate of o
miles per hour; one fourth OF the velocity of
the wind is lost TO the sails for the velocity of
the boat, is one fourth of the velocity of the
wind, the remaining three fourfts of the vclo-
city of the wind, will strike the sail with the
momentum of $50. The wind blows as il re-
spects the boat with the velocity of ID miles
per hour. Now the question is. it wind blow:
ing with the velocity of ~ miles per hour, will
strike a sail with momentum, of 400 which
momentum will force the Doat5 miles in one
hour, what momentum, will wind blowing
with the velocity Of IL miles per hour. STRIKE
the sail and how far will this momentum force
the boat in the same time? 1t will strike the
sail Gas before stated with a momentum of
$50; as the momentum is decreased, or iucreas
ed in qusdruple ratio TO the decrease. or in
crease of the velocity of the wind aud This
momentum will garry the boat | mile II29
yards, and 2 feet, in the same time: which add
ed TO the miles per hour, the velocity given
the boat by the steam, will make miles. II2S
yards, and feet when tie steam and wind
act at the same tiule upon The boat w.
DumfTieS, November Z, 1917
An election has just taken place in Boston
which has excited great deal of feeling and