12动载荷.pdf

ࡼ䕑㥋
1. 䞡䞣Ў P ⱘ⠽ԧˈҹࣔ䗳 v ϟ䰡ˈᔧ৞㋶䭓ᑺЎ l ᯊˈ
ℶ䕀ࡼˈབ೒⼎DŽذৢ⾦䗳೼ tޣࠊࡼ఼ࠍ䔺ˈ䍋䞡ोㄦҹㄝ
䆒৞㋶ⱘ῾៾䴶⿃Ў Aˈᔍᗻ῵䞣Ў Eˈࡼ㥋಴᭄ Kd ᳝ಯ
⾡ㄨḜ˖ l
EA v EA v v
(A) v ˗(B) ˗(C) ˗(D) 1 DŽ P
gPl t gPl gt gt
ㄨ˖D

2. ೒⼎ϔ䍋䞡ᴎ ৞ϔḍᎹᄫ䩶ˈ⬅催໘ϟ䰡DŽབ
ᇣࠄ v2 (v2ޣ೼ᯊ䯈䯈䱨 t ݙϟ䰡䗳ᑺ⬅ v1 ഛࣔഄ
˘v1)ˈ߭ℸ䯂乬ⱘࡼ㥋಴᭄Ў˖ v
v  v v  v
(A) 1 1 2 ˗(B) 1 1 2 ˗
2gt 2gt
v  v v  v
(C) 1 1 2 ˗(D) 1 1 2 DŽ
gt gt a 6a a
ㄨ˖C

3. 䭓ᑺЎ l ⱘ䩶ᴚ ABˈҹࣔ㾦䗳ᑺ㒩䪙ൖ䕈 OOĄᮟ䕀ˈ㢹䩶ⱘᆚᑺЎ U ˈ䆌
⫼ᑨ࡯Ў[V]ˈ߭ℸᴚⱘ᳔໻䆌ৃ㾦䗳ᑺZЎ˄ᔃ᳆ᑨ࡯ϡ䅵˅˖
Z
1 [V ] 1 [V]
(A) ˗(B) ˗ O
l U 2l U
A B
1 2[V ] 2 2[V]
(C) ˗(D) DŽ l/2 l/2
l U l U Oc
ㄨ˖D

4. 䭓ᑺЎ l ⱘ䩶ᴚ AB ҹࣔ㾦䗳ᑺ㒩䪙ൖ䕈 OOĄᮟ䕀DŽᏆⶹ䩶ⱘᆚᑺ U ੠ᔍᗻ
῵䞣 EDŽ㢹ᴚ AB ⱘ䕀ࡼ㾦䗳ᑺЎZˈ߭ᴚⱘ㒱ᇍԌ䭓'l Ў˄ᔃ᳆ᑨ࡯ϡ䅵˅˖
2 3
(A) UZ l / 12E˗ Z
(B) UZ2 l3 / 8E˗ O
2 3 ˗
(C) UZ l / 4E A B
(D) UZ2 l3 / 3EDŽ l/2 l/2
ㄨ˖A Oc
134
أᖗ೚ᄨDŽ೚Ⲭҹࣔ㾦䗳ᑺZᮟ䕀ˈᆚᑺЎ U DŽ⬅೚Ⲭأ೒⼎䩶䋼೚
˖ᖗ೚ᄨᓩ䍋ⱘ䕈ݙ῾៾䴶Ϟ᳔໻ℷᑨ࡯V max Ў
UG (d aZ) 2
(A) 1 ˗
8d 3
d1
UG (d aZ) 2
(B) 1 ˗ a
4d 3 d
4UG (d aZ) 2
(C) 1 ˗ Z G
d 3
8UG (d aZ) 2 a a
(D) 1 DŽ
d 3
ㄨ˖C

6. ⳈᕘЎ d ⱘ䕈Ϟˈ㺙᳝ϔϾ䕀ࡼᛃ䞣Ў J ⱘ亲䕂 ADŽ䕈ⱘ䗳ᑺЎ n 䕀/⾦DŽᔧ
䗳˅ˈ೼ࠊࡼ䖛⿟Ё䕈ݙ᳔໻ߛᑨޣࣔ˄ذࠊࡼ఼ B Ꮉ԰ᯊˈ೼ t ⾦ݙᇚ亲䕂ࠍ
࡯Ў˖
16ntJ nʌJ 32nJ 32nʌJ
(A) ˗(B) ˗(C) ˗(D) DŽ d
ʌd 3 td 3 td 3 td 3
B
ㄨ˖C A

7. ᴤ᭭ᆚᑺЎ U ˈᔍᗻ῵䞣Ў E ⱘ೚⦃ˈᑇഛⳈᕘЎ
Dˈҹ㾦䗳ᑺZ ԰ࣔ䗳䕀ࡼˈ߭݊ᑇഛⳈᕘⱘ๲䞣 Z
'D= DŽ
UD3Z 2
ㄨ˖D D
4E

8. ᴚ AB ऩԡ䭓ᑺ䞡䞣Ў qˈ៾䴶⿃Ў Aˈᔃ᳆៾䴶㋏᭄Ў WˈϞッ䖲᳝䞡䞣Ў
P ⱘ䞡⠽ˈϟッ೎ᅮѢᇣ䔺ϞDŽᇣ䔺೼Ϣ∈ᑇ䴶៤D 㾦ⱘ᭰䴶Ϟҹࣔࡴ䗳ᑺ a ࠡ
䖯ˈ䆩䆕ᯢᴚॅ䰽៾䴶Ϟ᳔໻य़ᑨ࡯Ў˖ P
[P  (ql / 2)]al cosD (P  ql)[1  (a sin D / g)] A
V 
gW A l
B a
P  ql (P  ql)a sin D
䆕˖V c 
A gA
[Pl  (ql 2 / 2)]a cosD

gW D
[P  (ql / 2)]al cosD (P  ql)[1  (asin D / g)]
V V c  
gW A
135
ᴚ AB ҹࣔ㾦䗳ᑺZ㒩 y 䕈೼∈ᑇ䴶ݙᮟ䕀ˈᴚᴤ᭭ⱘᆚᑺЎ U ˈᔍᗻ῵
Eˈ䆩∖˖
y
(1) ⊓ᴚ䕈㒓৘῾៾䴶Ϟℷᑨ࡯ⱘব࣪㾘ᕟ˄ϡ㗗㰥ᔃ᳆˅˗
Z
(2) ᴚⱘᘏԌ䭓DŽ
㾷˖ q AUZ 2 x
d x dx
O
AUZ 2(l2 x2) A B
F (x)
d 2 l l
UZ 2(l2 x2)
V (x)
d 2
2 2 3
UZ l 2UZ l
l 2u ³ (l2  x2)dx
2E 0 3E
10. ೒⼎ḹᓣ䍋䞡ᴎЏṕ⬅ϸḍ 16 োᎹᄫ䩶㒘៤ˈЏṕҹࣔ䗳ᑺ v=1 m/s ৥ࠡ⿏
ℶᯊˈ䞡⠽৥ࠡᨚࡼˈ䆩∖ℸⶀᯊṕݙ᳔໻ℷذࡼ˄ൖⳈ㒌䴶˅ˈᔧ䍋䞡ᴎさ✊
ᑨ࡯˄ϡ㗗㰥᭰ᔃ᳆ᕅડ˅DŽ
2 z
v 2
㾷˖an = = m/s
U