The sun., 1916-12-24
ENERGY IN SURF CAST
DISCUSSED FOR ANGLER
''Switch Reel" Tells How II Is
COmputed-What Fig
urpS SHOW.
~ SWITCH REEL.

An Interested student Of the surf rod
asked me n few days ago how the energy
applied 10 the I ounce lead used In the
surf cas-, was computed.
The answer may be interesting to
others. and here 1t is:
There are three basic factors In al
mechanical problems. viz. time. length
these, the length and weight. are readily
o~btainablc, while the third, time. can lac
measured approximately with "A stop
watch.
Given n cast OF asa feet with a { ounce
lead In g.. seconds. what is the energy
applied to the lead?
! use these figures as an example he
cause Or. Simon once madc n cast of 35i
feet. which MIR. Willis " Finch timed
and found to consume approximately a.,
seconds IN flight.
A. in the accomplishment Of a cast
energy Is applied In two directions. YER
tically and horizontally. we VIII first
consider the vertical energy. 81 that con.
sumed In elevation.
In it's hight the lead reached a certain
height and then fell through the same
distance, 1t is clear that during one
half of the time consumed tho lead was
rising, aud during the other half 1t was
falling. Here We can cali upon the law
of falling bodies to tell us how far a
ounce lead will fall in cis seconds. and
with what energy it will strike.
The formula is. gfxtr energy, y he
Ing the velocity OF n falling body ~ iht
expiration OF one second. or So feet
the time. or .1.j seconds, and ~ IN,
! weight. .95 pound. The energy therefore
bccomes 81 2N2i25Nej. Or IA foot
pounds. So much for elevation or VERT.
.. .,arps IIn,gxn,4.li, ID. tho l.aI lao.
travelled 354 feet in i"5 seconds lts
rate OF prog ression In the forward direc'
tion was therefore at a mean velocity OF
a. i.2I feet per second. or $50 feet
This velocity. multiplied hy the weight
I % pound. gives an energy of 20.3 : foo
pounds.
Thus the total energy realised upoI ii
the cas-, was the sum of the two. o
31.t foot pounds. Note the words II
italics. The figure az is not the energy
applied to the cast. but II il what wa
translated into distance. The cast wa
not given the best possible elevation ri
the energy consumed in elevation an'
regeneratcd in failing would cxactl,
equal the energy consumed in the horI
zou,al direction. A little more elevation
would have kept the lead In flight &
little longer and more distance wOul,
have been accomplished
Let MS imagine a cast in which 90
foot pounds IL applied vertically and tn
same energy applied horizontally. or
total ~ i06 foot pounds. What will b,
the distance accomplished"
Reversing the above methods of com
putation AMI retaining the same hort
zontal velocity II Is found that the lea,
would consume 2.i9 seconds in ~acqulrln,
a striking energy of goa foot pound
and cover a distance OF 4liS feet.
Evidently tho east was too low w
always thought the doctor fails to Civ
his casts enough elevation.
Taking the cast apart and putting I
together In another way let us diyid
the energy realized upon into two equa
parts, or l9,I foot pounds, imaginin,
cach expended IN It's own direction. an,
II is found that the distance which woul
have been accomplished is ASIA feet. q
within five feet OF the worlds record
Boys, look out for the doctor He
very apt to come back