Tulsa daily world. [volume] (Tulsa, Indian Territory [Okla.]) 1905-1919, 1918-05-08
USE MATHEMATICS AND
PREVENT BLOWING OUT
Possible 10 Trace Blow Outs To
Bumps Received Months Ago;
striking Fore Explained.

You have bounced off your seat.
Of Cousc and heard the cries OF pas
sengers in the rear seat to "cut her
down little" Just because you
struck hole or rocky. uneven spot
In the road Then you wondered II
any damage was done. You slowed
mp for short space and the old
boat seemed to go along all right
and you spceded her up again.
Perhaps a day or two later you
are forced To change a tire Upon
showing 1t to the repair man. who
tells you that the carcass Of the tire
is in need. of repair because of a
bruise. commonly called "stone
bruise," you remark, "rathtr strange
have no recollection of hitting a
stone; / have travelled only on i'm
proved state Dads and city streets" ."
But you fan to recall the severe
shock your car and It's occupants ex-
perienced when you hit the bump or
hole In the road
one barely stops to consider the
force of such stroke when deliv-
cred to the tire upon meeting such
an obstI uction or road irregularity
Back to school days for mo-
ment II you will, and recall that old
law of phys The energy OF a
moving body varies as the square OF
its velocity Apply this to your car
and YOU viii note that by dou bling
the speed the energy is increased
four times. Triple your speed and
! the violence OF the road shocks de-
! liver blow To your tires, the force
OF which is increased nine times.
While an increase of speed gray
ity mul .iplles the force OF the road
shocks the direction OF the blow Is
also changed. In driving slowly over
a SLIGHT obstruction or depression.
the force OF the blow is downward,
due to the dead weight OF the car
, and the shock Is received in n Nerti-
! cal direction. which is easily alb
sorbed by the cushion of air and
the springs on the car. without IN
Jury TO either.
by speeding up the car. the force
OF the blow is downward. due 10 the
dead weight Of the car and the
shock is received in vertical di-
rection, which is easily absorbed by
| the cushion Of air and the sprngs on
the car, without injury to either.
The cuEnloninE effect OF springs is
not used hence they do not absorb
= 'iOTlGpHldi pluW NuAu 10
aimed directly at the axle; there
fore, IL is dead blow on the tire,
which overtaxes its cushioning eff
feet and stretches it's inner carcass
construction, to such degree In
ward that the inner ply of cords or
fabrics Is strained or broken and
later deveiops into a blow-o The
length OF tIiue for a blow out to de-
VClop depends on the force Of the
blow, which in turn is governed 'hy
the speed OF the car when the blow
was first received.
Thus you will note that the collid-
ing force OF an automobile Is gov
erned absolutely by the speed. Ii
sou should drive your automobile
off the roof Of your house, which We
will say Is about forty feet above
the ground. what would be the eff
feet rlihle, you say. Quite
right. The force OF the impact when
the car hi the ground would Re
equal to lis striking or collision
force OF being driven at a speed OF
So miles per hour
A dron OF 16S feet is equal to a
force delivered TO a car when trav-
euinG al rate OF seventy miles per
hour By doubling the speed, you
increase the force Of the blow four
fold.
Yea. rare,y tho responsibility OF
the tire il Great.