CRITERIA 1. The methodology and experimental set-up were described in detail. 2. The data were presented properly using tables/graphs. 3. The analysis of data and conclusions were sound and correct. 4. The theoretical theoretical equations were deried completely and used correctly. !. The report used correct grammar " tense and presented in the proper format.
Score
&emarks
RATING
I.
O!ECTI"ES
4"is experiment aims •
4o identify t"e !"ara!teristi!s and type of relations"ip *etween t"e flow rate 567 and
•
(ydrauli! (ead 5(7 of t"e water exiting t"e re!tangular weir. 4o !ondu!t several measurements at different flow rates to produ!e a !ali*ration !urve of
•
t"e rainfall apparatus. 4o familiari#e t"e *asi! fun!tions of t"e rainfall apparatus for furt"er experimentation.
II.
#ROCE$%RES
4"e flow of water *eginning from t"e rotameter was t"en dire!ted to t"e pipe !onne!ting valves C and D. 4"ese designated valves were t"en simultaneously unlo!ked w"ile 8alve ' was *eing !losed. 4"e water flowed towards t"e final !"am*er until it overflows t"e weir. 9"en t"e flow is steadied and !almed$ t"e flowrate and "eig"t a*ove t"e weir was re!orded a!!ordingly per group. 4"e pro!edure was repeated until all assigned flow rates were a!!omplis"ed. III.
SA&#'E CA'C%'ATION
Conversion of flow rate from lpm to m +:s 2.5
I".
3
l min
×
1m
1000 l
×
1 min 60 s
4
−
0.417 × 10
=
m
3
s
RES%'TS AN$ $ISC%SSION
4a*le 1. Experimental Data 1st 4rial lp m ) / ,
+
m :s 2 2.++ + 2.// ; 1.22 2 1.++
)nd 4rial ( 2
lpm
1-
).-
)2.-
.-
); +1.-
/.,.-
+
m :s 2 2.1 ; 2.;2 1.2, + 1.1
+rd 4rial ( 2
lp m
1/
+
)+
-
)< ++
; <
m+:s 2 2.-2 2 2.,+ + 1.1/ ; 1.-2
t" 4rial ( 2
lpm
1;
+.-
)
-.-
+2 +-
;.<.-
m+:s 2 2.-, + 2.<1 ; 1.)2 1.-,
( 2 1< )+2.+-
12 1) 1 1/ 1, )2
+ 1.// ; ).22 2 ).++ + ).// ; +.22 2 +.++ +
+; 1.;.-1.--.-<
12. 1). 1. 1/. 1,. )2. -
; 1.;2 ).2, + ).1 ; ).;2 +.2, + +.1 ;
+<
11
+
1+
,
1-
-+
1;
-/
1<
/1
)1
2 1.,+ + ).1/ ; ).-2 2 ).,+ + +.1/ ; +.-2 2
11. 1+. 1-. 1;. 1<. )1. -
+< < - -< /)
+ 1.<1 ; ).)2 ).-, + ).<1 ; +.)2 +.-, +
2 -2.-/ -<./+
Note ( is expressed in millimeters and flow rates are expressed in 12= m+:s 4"e diagram s"own *elow is a grap"i!al representation of t"e Experimental Data !olle!ted from t"e a!tivity.
>low &ate 567 vs (ead 5(7 +.-
f(x) = - 0x^3 + 0x^2 + 0.01x R² = 1
+ ).-
>low &ate 5m+:s7
) 1.1 2.2
2
12
)2
+2
2
-2
/2
;2
(ead 5mm7 >low &ate vs (ead
0oly nomial 5>low &ate vs (ead7
>igure 1. &e!tangular 9eir Cali*ration Curve
4"e main purpose of t"is experiment is to !reate a !ali*ration !urve for t"e rainfall apparatus *y !olle!ting t"e data of t"e flow rate 567 and "ead 5(7 produ!ed *y t"e given re!tangular weir. ?t must *e !ondu!ted wit" utmost a!!ura!y as t"is will serve as
t"e *en!"mark for future experiments. 3inimi#ing errors !ould prove useful$ most espe!ially in t"e grap"ing of t"e !ali*ration !urve.
>rom t"e data o*tained in t"e pro!ess of t"e experiment$ it is inferred from t"e ta*le a*ove t"at t"ere is a dire!tly proportional relations"ip *etween t"e flow rate 567 of water from t"e rainfall apparatus and its e@uivalent "ead 5(7 of t"e water flowing from t"e given re!tangular weir as well. As t"e flow rate assigned is in!reased per test$ t"e "ead of t"e ex!ess water pouring from t"e re!tangular weir in!reased along wit" it. All o*tained results are !onsistent wit" w"at is proBe!ted on t"e grap" of t"e !ali*ration !urve wit"
t"e
e@uation
of
y
=,E=2/x+
2.221)x)
2.212/x
& 2.<<,-1.
".
CONC'%SIONS
After t"e experimentation was !ondu!ted$ it was identified from t"e experimental data t"at t"ere is a dire!tly proportional relations"ip *etween t"e "eig"t of t"e "ead 5(7 of t"e water flowing from t"e weir and t"e flow rate 567 wit"in t"e rainfall apparatus. 4"is trend is parti!ularly !onsistent wit" w"at is plotted in t"e grap" of t"e !ali*ration !urve t"at will *e used for future referen!e in t"e !oming experiments. Cali*rating t"e re!tangular weir is important *e!ause it will serve as t"e *en!"mark in t"e future la*oratory tests. ?t is extremely vital t"at a!!urate and pre!ise measurements are taken to produ!e @uality results in t"e su!!eeding experiments.
"I.
RECO&&EN$ATIONS
?t is advised to *e as responsive as possi*le in wat!"ing and o*serving t"e flow rate. (uman error will always *e present to some degree *ut minimi#ing it !ould *e "elpful in !olle!ting pre!ise and a!!urate data. Se!ond"and opinions in reading t"e in!rements *etween flow rate is suggested to a!"ieve *etter data and grap"s. ?t is advised to wait a few se!onds for t"e water to sta*ili#e after ea!" flow rate in!rement to redu!e
any possi*le !ali*ration errors. ?t is *est to do preliminary resear!" and to study *efore"and to value t"e importan!e of t"e a!tivity. 4"e knowledge and information gained from t"is experiment will prove to *e useful in t"e future la*oratory a!tivities. ?f possi*le$ t"e a!@uisition of more e@uipment would prove *enefi!ial so t"at students may simultaneously perform t"e a!tivity and not "ave to wait for or merge wit" ot"er groups. ?n !omputation$ it is more effi!ient to make use of 3i!rosoft ex!el and manipulate t"e !ells wit" formulas$ t"is will save time and is less likely to *e su*Be!ted to input error in t"e !al!ulator for manual solving.
