Ch.2 200911613

[2.1] 5m . 100m . () 1.020 .

[ 2.2] , 2,000m () . Pa abs, .

(2.2.12)

(2.2.9)

() (2.2.7) (1.7.1) .

[2.3] ()(lapse rate) . . () (dry adiabatic laps rate) . 30ft 20oF . ?

(a) At standard atmospheric lapse rate = -0.00651oC per meter and t0 =20oC.(a) .(b) At an inverted lapse rate = 0.00365oC per meter.(b) () .

(2.2.7) (2.2.14)

(, 7.1)

, T1 P0 , K . 2 K 1.4. P/PO

y

For = -0.00651oC per metre, R = 287 mN/(kgK), a = 2.002, and y = 3201 m. For the atmospheric temperature inversion = -0.00365oC per metre, a = -0.2721, and y = 809.2 m.(a) a=1.994 y=10570 ft(b)

[ 2.4] 2.7(a) A B , S=0.8 . h1=300mm, h2=200mm, h3=600mm . (a) pA-pB Pa? (b) pB=50 kPa 730 mmhg A () m ? (a)

(b)

(a)

[ 2.5] 2.8 . S2 =1.10, a/A=0.01, R=5mm, t=20, 760mmHg. Pa?

. (2.4.1)

[ 2.6] (gate) ( 2.12) (hinge) . O.8 . . (a) , (2.5.2) . (b) , (c) P.

2.12

(a) 2.12

x y , y = 8 x = O, y = 13 x : 6a, b , a, b 1 x y .

y=13, x=6 y=18, x=0

, .

(2.5.2)

(b) () .

(2.5.8)

x () , .

(2.5.11)

, () () O.32 ft .

(c) , CD

[ 2.7] y[ 2.14(a)] . . y . 2.14 ()

. () [ 2.14(b)] , . 0 [ 2.14(c)]. . . 3,000N . 2.14(d) () . , , 0

. 2 3 . Newton-Raphson( B.5) ().

y . , y=2.5 y . , y=2.196 m .

[ 2.8] (gravity dam) . . 2.15 . , . 1ft . , , (foundation pressure) ( )(hydrostatic uplift) . , ()(hydrostatic head) 1/2 , 0 . , . , . () () . , , . 0

. 2.15 . , . ,

, . () . 0 . , .

3 . () 3 .

[ 2.9] 2.16 . y . y .

[ 2.10]

[ 2.11] (2.22). . 1m . (a) (b) .

[ 2.12]

[ 2.13]

[ 2.14] 2.30 20ft 60ft, 225ton(2,000 lb). 1.0ft . .

[ 2.15] 1Mkg () 2.32 . 2.0m 0.5m . y-y (rolling) x-x (pitching) .

: :

[ 2.17] 6*6, 2

. .

.

2.35

.

0 (2.9.2)

.

y=0

[ 2.18] 1.2 200 rpm . 1m A 70 kPa. A 2m , 1.5m B ? (2.9.5) .

. (2.9.6) . . 2.38 ()

[2.19] 4ft () 30 8.02rad/s . 0 . .

2.38 0 A . (2.9.6)

. A 1.0ft .

*