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Old-Exam.Questions-Ch-14 (Dr. Gondal, Phys101)0!"

Q#. A penguin (bird) floats first in a fluid of density 1 = 1.0 , then in a fluid of density 2 = 0.95 , and then in afluid of density 3 = 1.1 . $an% the densities of the fluids a ording to the a!ount of fluid displa ed by the

penguin, G$E& E' first. A) 2, 1, 3Q10. A plasti sphere floats in "ater "ith 0.50 of its #olu!e sub!erged. $his sa!e sphere floats in oil "ith 0.%0 of its #olu!e sub!erged. &eter!ine the density of the oil.Q11. $he open #erti al tube in 'ig. 3 ontains three fluids of densities 1 = 300 g !3, 2 = %00 g !3 and 3 =500 g !3, "hi h do not !i*. 'ind the pressure at point +. A) 1.03 * 105 a

Q1" . 'ig. % sho"s an ideal fluid flo"ing in a hori-ontal tube. $he pressure, #elo ity, and tube ross se tion area at point 1 and 2 are ( 1, #1, A1) and ( 2, #2, A2), respe ti#ely. f 1=/.0 * 10% a, A1=%A2, 2 = .0 *10% a andA2= 2.0 * 10 3 !2, at "hat #olu!e rate does "ater flo" through point 2 $a e density of "ater to be 1000 g !34(A) 0.013 !3 s

0!1 Q" . A unifor! blo of "ood floats in "ater "ith t"o thirds of its #olu!e sub!erged. 6hat is the density of the"ood A) 0. 7 g ! 3

Q"4. 8n a standard day (at!ospheri pressure), a pressure gauge instru!ent belo" the surfa e of the o ean(Specific Gravity = 1.025) reads an absolute pressure of 1.% * 10 a. o" deep under"ater is this instru!ent A)129 !Q" . A #erti al ross se tion of a si!ple geologi al !odel of the earth that re:uires !ountains to ha#e roots issho"n in 'igure 10. At so!e hori-ontal le#el in the fluid !antle ( alled the level of compensation ), the pressure hasa onstant #alue (the pressures at points A and + in the figure are e:ual). o" deep !ust the root (d) of the!ountain appro*i!ately be A) 13 !

*i+. , 0!" *i+. 4, 0!" *i+. 10, 0!10 "0 "

;23. 6ater is pu!ped out of a s"i!!ing pool at a speed of 5.0 ! s through a unifor! hose of radius 1.0 !. 'indthe !ass of "ater pu!ped out of the pool in one !inute. (&ensity of "ater = 1000 g ! 3).(Ans 9% g);2%. A large tan open to at!osphere is filled "ith "ater. 'ig sho"s this tan "ith a strea! of "ater flo"ingthrough a hole (open to at!osphere) at a depth of %.00 !. $he speed of "ater, # 2, lea#ing the hole is ( Ans /./5 ! s);25.A 10 g spheri al ob

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Q10. A ga$den hose has an inne$ diamete$ of 1 mm. 'he hose can "" a 10 "ite$ bucket in *0s. Find the s eed of the wate$ at the end of the hose )1 ite$ = 10 3 m3-.)Ans: *.2 m/s-Q11. ate$ 4ows th$ough a i e as shown in Fig. 7 . At the "owe$ e"e5ation! the wate$6s s eed)5A- is 2.0 m/s and the gauge $essu$e ) A- is 7.2 8 10+ a. Find the gauge $essu$e at thehighe$ e"e5ation ) %-. ) iamete$ at A = .0 cm! diamete$ at % = +.0 cm and the e"e5ation of% $e"ati5e to A is *.0 m- )Ans: +. 0 k a-

Fig. 7, T0710 "

Q . 'ig. % sho"s an ideal fluid flo" in a hori-ontal tube. $he pressure, #elo ity, and ross se tional area of fluid at point1 and 2 are ( 1, # 1, A1) and ( 2, # 2, A2) respe ti#ely "ith A 1@A2. 6hi h one of the follo"ing state!ents is orre t A) # 1#2 B 1@ 2Q! . A "ooden bo* has been found to floats in three different fluids of densities 1 (fluid 1) = 0.9 g cm3, 2 (fluid 2) = 1.0

g cm3, 3 (fluid 3) = 1.1 g cm3. 6hi h one of the follo"ing state!ents is true (A) the three fluids e*ert the sa!e buoyantfor eQ# .A C tube of onstant ross se tional area, open to the at!osphere, is partially filled "ith g ( g =13. g ! 3). 6ater( " =1.00 g ! 3) is then poured into both ar!s. f the e:uilibriu! onfiguration of the tube is as sho"n in the 'ig. 5 "ithh3= 1.00 !, deter!ine the #alue of h 1. (>ote that h 1, h 2 and h 3 are not dra"n to s ale). A) 12. cmQ10 . $he open end of a ylindri al pipe has a radius of 1.5 cm. 6ater (density = 1.0?10 3 kg m3) flo"s steadily out of thisend at a speed of 7.0 m s. $he rate at "hi h !ass is lea#ing the pipe is A) %.9 kg s

0 1Q" . $he open #erti al tube in 'ig. 13 ontains t"o li:uids of densities 1 = 1000 kg m3 and 2 = /00 kg m3, "hi h do not!i*. 'ind the gauge pressure (pressure due to the li:uids only) at the botto! of the tube. (A 9000 a );2%. An Alu!inu! blo of density 2.70 g cm3 has a "eight W in air and has a "eight W app in "ater "hen o!pletelysub!erged. f ( W W app ) is e:ual to 19 N , the #olu!e of the blo is A) 0.020 m3

Q" . 6ater is pu!ped through a hose of unifor! ross se tion as sho"n in 'ig. 1%, fro! the lo"er le#el (1) to the upperle#el (2). 6hi h of the follo"ing e*presses the orre t relationship bet"een #elo ity and pressure at the t"o le#els A) v1= v2 and p 2 p1Q" . 6ater flo"s through a hori-ontal tube fro! point 1 ( ross se tional area A 1) to point 2 ( ross se tional area A 2), assho"n in 'ig. 15. f A 1 = 2A 2 and v1 = 10 m s, the hange in the ineti energy (DE) of 1.0 m3 of "ater in !o#ing fro!

point 1 to point 2 is A) 1.5 * 10 5 J )

*i+. 4, 0 " *i+. , 0 " *i+. 1 , 0 1 *i+. 14, 0 1 *i+. 1 , 0 10 "

Q " / A unifor! C tube is partially filled "ith "ater. 8il, of density 0.75 g ! 3, is poured into the right ar! until the"ater le#el in the left ar! rises 3.0 ! (see 'ig /). $he length of the oil olu!n ( h) is then (Ans %.0 !)Q "4/ $he di!ensions of a boat ( boat = 150 g ! 3) is 3.00 ! * 3.00 ! * 1.00 !. 6hat !a*i!u! load an it arry in sea"ater ( sea "ater = 1020 g ! 3) "ithout sin ing (Ans 7/30 g)Q " / A "ater line enters a house 2.0 ! belo" ground. A s!aller dia!eter pipe arries "ater to a fau et 5.0 ! abo#eground, on the se ond floor. 6ater flo"s at 2.0 ! s in the !ain line and at 7.0 ! s on the se ond floor. f the pressure inthe !ain line is 3.0 * 10 5 a, then the pressure on the se ond floor is ($a e the density of "ater to be 1.0 * 10 3 g ! 3)(Ans 2.1 * 10 5 )Q " / $he rate of flo" of "ater through a hori-ontal pipe is 2.00 ! 3 !in. Fal ulate the speed of flo" at a point "herethe dia!eter of the pipe is 10.0 !. (Ans %.2% ! s).

1%2

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*i+. !, 0 " *i+. , 0 1 *i+. , 0 1 *i+. !, 0 1

0 1/

;G23 e#eral ans of different si-es and shapes are all filled "ith the sa!e li:uid to the sa!e height h ( ee 'ig. ).$hen (Ans the pressure on the botto! of ea h an is the sa!e)Q "4/ 'ig. 7 sho"s a C tube "ith ross se tional area A and partially filled "ith oil of density . A solid ylinder, "hi hfits the tube tightly but an slide "ithout fri tion, is pla ed in the right ar!. $he syste! is in e:uilibriu!. $he "eight of the ylinder is (Ans AH g)Q " / An ob in air and 20> "hen the ob "hen the ob

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Q11 Fonsider a large, losed, ylindri al tan "ith oil inside it. $here is a s!all hole at a height of 1 ! fro! the botto!of the tan . $he air abo#e the oil is !aintained at a pressure 1.5 * 10JJ5 a (see 'ig 7). 'ind the speed at "hi h oillea#es the hole, "hen the oil le#el is 20 ! abo#e the botto! of the tan . ($he density of oil is /50 g !JJ3). (Ans 22! s)

0""/ Q"" $he density of "ater and oil are 1.0 g !JJ3 and 0./0 g !JJ3 respe ti#ely. $he height h of the olu!n of oil, sho"n in 'ig.5, is (Ans 10 !) Q" An in o!pressible ideal li:uid flo"s along the pipe as sho"n in 'ig. . $he ratio of the speeds #2 #1 is A1 A1 A2Q"4 +ernoulliMs e:uation an be deri#ed fro! the onser#ation of ( Ans energy )Q" A li:uid of density 791 g !JJ3 flo"s s!oothly through a hori-ontal pipe (see 'ig. ). $he area A2 e:uals A1 2.$he pressure differen e bet"een the "ide and the narro" se tions of the pipe ( 1 2) is %120 a. 6hat is the speed #1(Ans 1./ ! s)

*i+. !, 0 " *i+. 10, 0 " *i+. , 0 1 *i+. , 0"" *i+. , 0""

0"1/ Q# A unifor! C tube is partially filled "ith "ater. 8il, of density 0.75 g !JJ3, is poured into the left ar! untilthe "ater le#el in the right ar! rises 3 ! (see 'ig. 3). $he length of the oil olu!n, H, is then (Ans / ! )Q10 An ob in air, 20 > "hen the ob !JJ2) at the botto! of the tube. (Ans 1.3J 10JJ5 a)Q 6ater (density = 1.0 * 10JJ3 g !JJ3) flo"s through a hori-ontal pipe as sho"n in ' NCIL 2. At the "ider endits speed is %.0 ! s and at the narro" end its speed is 5.0 ! s. $he & ''LIL>FL in pressure, 2 1, bet"een the t"oends is (Ans O%.5 * 10JJ3 a)Q! A 3.20 g blo of !etal !easuring 15 ! P 10 ! P 10 ! is suspended fro! a s ale and totally i!!ersed in"ater as sho"n in ' NCIL 3. 6hat is the ILA& >N of the spring s ale (in >) (density of "ater = 1.0J 10JJ3

g !JJ3) A1 1 .7Q# A blo of "ood floats in "ater "ith t"o third of its #olu!e sub!erged. 'ind the &L> $Q of the "ood (in

g !JJ3). ( &ensity of "ater is 1.0J 10JJ3 g !JJ3). (Ans 7 g !JJ3) Q10 $he rate of flo" of "ater through a hori-ontal pipe is 2.0 !JJ3 !inute. &eter!ine the LL& of flo" at a point"here the radius of the pipe is 5.0 !. (Ans %.2 ! s.)

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