Experiments
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19
"Sweet Spot" Computer Program
The following is a listing of the "Sweet Spot" computer program written by Scott K. Perry of American River College,
Sacrament, CA, using Quickbasic 4.5.
PRINT “Y-Impact (m)”; TAB(16); “Cart-Speed
(m/s)”; TAB(35); “Omega (rad/sec)”;
TAB(54); “Impulse at Pivot (N
sec)”
COLOR 15
PRINT
FOR k = 1 TO 9
r = k / 10
a = Mc / 2 + (Mc
r) ^ 2 / (2
I)
b = –Mc
Wo
r
c = –PE + (1 / 2)
I
Wo ^ 2
v = (–b + SQR(b ^ 2 – 4
a
c)) / (2
a)
w = (I
Wo – Mc
r
v) / I
DeltaP = Mc
v + Ms
w
L / 2 – Ms
Wo
L / 2
v = INT(1000
v + .5) / 1000
w = INT(1000
w + .5) / 1000
DeltaP = INT(100
.5) / 100
PRINT TAB(5); r; TAB(20); v; TAB(39); w;
TAB(60); DeltaP
NEXT
PRINT: PRINT
INPUT “Would you like to input different values
”; a$
IF a$ < > “N” and a$ < > “n” GOTO Begin
END
REM Program: SWEET SPOTS and PER
-
CUSSION POINTS (Fixed Pivot)
REM (Version: 15DEC91)
CLS
LOCATE 1, 1
INPUT “What pullback angle will you be
using for this experiment (deg.)”; theta
INPUT “What is the mass of your meter-stick
’bat’ (kg); Ms
g = 9.8: Mc = .5: L = 1: theta = theta / 57.3
COLOR 15
Begin:
CLS
LOCATE 1, 1
INPUT “How far from the center-of-mass is
the pivot located (m)”; S
INPUT “How large is the load mass (kg)”; m
IF m = 0 GOTO Skip
INPUT “ How far is the load mass from the
pivot (m)”; y
Skip:
I = (1 / 12)
Ms
L ^ 2 + Ms
S ^ 2 + m
y ^ 2
PE = (Ms
S + m
y)
(1 – COS(theta))
g
Wo = SQR(2
PE / I)
h = (1 + 2
(y / L)
(m / Ms))
(1 –
COS(theta))
L / 2
PRINT: PRINT
COLOR 14