Mehlala e 9 ea Lipotso tsa Khoebo
1. Matla a di-Newton tse 20 a sebediswa bolokong ho fihlela boloko bo tsamaya sebaka sa dimithara tse 2. Mosebetsi o etswang ke matla a F bolokong ke…
Puisano
Hoa tsebahala :
Matla (F) = 20 N
Ho falla (ma) = limithara tse 2
Angle = 0 (lehlakore la matla le tšoana le lehlakore la ho falla kapa lehlakore la matla le tsamaisana le lehlakore la ho falla hoo sekhutlo se entsoeng ke matla le ho falla e leng lefela)
E botsitsoe : Boiteko (W)
Jawab :
Catatan :
Haeba tataiso ea matla e tšoana le tataiso ea ho falla, bala mosebetsi u sebelisa foromo W = F s, ntle le ho hloka ho eketsa cos tit.
2. Ntho e eme e sa sisinyehe holim'a bokaholimo bo boreleli ba fatše. Matla F = 10 N a sebelisoa nthong eo, a etsa sekhutlo sa 30o kgahlanong le bokaholimo ba mokatong. Haeba ntho e tsamaya mithara e le 1, ke mosebetsi o mokae o etswang ke matla a F hodima ntho eo?
Puisano
Hoa tsebahala :
Matla (F) = 10 Newton
Matla a lebileng ho falla (Fx) = F cos 30o = (10)(0,5√3) = 5√3 Li-Newton
Ho falla (ma) = limithara tse 1
E botsitsoe : boiteko (W) ?
Jawab :
W = Fx s = (5√3)(1) = 5√3 Joule
3. Ntho e boima ba 1 kg e oela ka bolokolohi ho tloha bophahamong ba limithara tse 2. Haeba lebelo le bakoang ke matla a khoheli e le 10 m/s2, fumana mosebetsi o etsoang ke matla a khoheli nthong eo!
Puisano
Hoa tsebahala :
Boima ba ntho (m) = 1 kg
Bophahamo (h) = limithara tse 2
Ho potlaka ka lebaka la matla a khoheli (g) = 10 m/s2
E botsitsoe : Mosebetsi o etsoang ke matla a khoheli nthong (W)
Jawab :
Tsela eo matla a khoheli kapa boima ba 'mele (w) bo shebileng tlase ka ho otloloha, tsela eo ho falla ha ntho (s) ho eona le eona e shebileng tlase ka ho otloloha e le hore matla a khoheli a be ka lehlakoreng le le leng le tsela eo ntho e fallang ka eona.
W = F s = wh = mgh
W = (1)(10)(2) = 20 Joule
4. Seliba se fanyehiloe ka boima ba 1 kg e le hore seliba se be le keketseho ea bolelele ba 2 cm. Haeba lebelo le bakoang ke matla a khoheli e le 10 m/s2, fumana (a) sekgahla sa selemo (b) mosebetsi o etswang ke selemo hodima mojaro
Puisano
Hoa tsebahala :
Boima (m) = 1 kg
Ho potlaka ka lebaka la matla a khoheli (g) = 10 m/s2
Keketseho ea bolelele ba selemo (x) = 2 cm = 0,02 metres
E botsitsoe : kamehla ea selemo le mosebetsi o etsoang ke matla a selemo
Jawab :
(a) Sephetho sa selemo
Foromo ea molao oa Hooke :
F = k x.
Fetola foromo ena ho bala botsitso ba selemo:
k = F / x = w / x = mg / x
k = (1)(10) / 0,02 = 10 / 0,02
k = 500 Newton/mithara
(b) Mosebetsi o entsoeng ke lebotho la selemo
W = – ½ kx2
W = – ½ (500)(0,02)2
W = – (250)(0,0004)
W = -0,1 Joule
Mosebetsi o etsoang ke matla a selemo hodima mojaro o mobe hobane tataiso ya matla a selemo e fapane le tataiso ya ho falla ha mojaro.
5. Lebokose le ntseng le le hodima mokatong le potlakiswa ka matla a 10 N hoo lebokose le tsamayang sebaka sa dimithara tse 2. Haeba matla a sutumetsang a le ka lehlakoreng le le leng le ho falla ha lebokose mme lebokose le sebetswa ke matla a kinetic friction a 2 Newtons, jwale mosebetsi o felletseng o entsweng lebokoseng ke...
Puisano
Hoa tsebahala :
Matla (F) = 10 Newton
Matla a khohlano a Kinetic (F)k) = 2 Newton
Ho falla (ma) = limithara tse 2
E botsitsoe Boiteko bohle (W)kakaretso)
Jawab :
Mosebetsi o etsoang ka likhoka (F):
W1 = F s cos 0 = (10)(2)(1) = 20 Joule
Mosebetsi o etsoang ke matla a kinetic friction (F)k):
W2 =Fk s = (2)(2)(cos 180) = (2)(2)(-1) = -4 Li-joule
Boiteko bohle ke:
Wkakaretso = W.1 - W2
Wkakaretso = 20 - 4
Wkakaretso = 16 Joule
6. Ntho e boima ba 5 kg e hodimo ho lefatshe ka dimithara tse 10. Ho potlaka ka lebaka la matla a khoheli = 10 m/s-2. Boiteko bo hlokahalang ho tsamaisa ntho ho ea bophahamong ba limithara tse 15 ho tloha holim'a lefatše ke...
A. . 75 Joule
B. . 250 Joule
C. . 500 Joule
D. . 750 Joule
E. 1.250 Joule
Puisano
Hoa tsebahala hore:
Boima ba ntho (m) = 5 kg
Bophahamo (h) = limithara tse 10
Ho potlaka ka lebaka la matla a khoheli (g) = 10 m/s2
O botsitse: Leka ho suthisetsa ntho bophahamong ba limithara tse 15
Karabo:
Boiteko ba ho tsamaisa ntho bonyane bo lekana le matla a khoheli a sebetsang nthong eo.
Foromo ea mosebetsi o entsoeng ka matla a khoheli:
W = wh = mgh
Tlhaloso: W = boiteko, w = matla a khoheli, h = bophahamo, m = boima, g = ho potlaka ha matla a khoheli
Foromo ea mosebetsi o entsoeng ke:
W = wh = mgh = (5 kg)(10 m/s2)(10 m) = 500 kg m2/s2 = 500 Joule
Karabo e nepahetseng ke C.
7. Ntho e boima ba 2 kg e tsamaya hodima bokahodimo bo boreledi ka lebelo la 2 m/s.-1 Metsotsoana e seng mekae hamorao ntho eo e ile ea tsamaea ka lebelo la 5 ms-1 Mosebetsi o entsoeng nthong ena nakong ena ke...
A. 4 Joule
B. 9 Joule
C. 15 Joule
D. 21 Joule
E. 25 Joule
Puisano
Hoa tsebahala hore:
Boima ba ntho (m) = 2 kg
Lebelo la pele (v)o) = 2 ms-1
Lebelo la ho qetela (v)t) = 5 ms-1
O botsitse: Mosebetsi o etsoang nthong nakong eo ea nako
Karabo:
Theorem ea matla a kinetic ea mosebetsi e bolela hore mosebetsi oohle o entsoeng nthong o lekana le phetoho ea matla a kinetic a ntho.
W = ΔEK = EK2 – EK1 = 1/2 mvt2 – 1/2 mvo2 = 1/2 m (vt2 - vo2) = 1/2 (2)(52-22) = (1)(25-4) = 21 Joule
8. Tafole e boima ba 10 kg qalong e phomotse fatshe e boreleli, e sutumelletsoa metsotsoana e 3, e tsamaea ka mola o otlolohileng ka lebelo la 2 m/s.-2Boholo ba boiteko bo etsahetseng e ne e le…
A. 20 Joule
B. 30 Joule
C. 60 Joule
D. 180 Joule
E. 360 Joule
Puisano
Hoa tsebahala :
Boima (m) = 10 kg
Lebelo la pele (v)o) = 0 (qalong tafole e eme)
Nako ea ho arohana (t) = metsotsoana e 3
Ho potlaka (a) = 2 m/s2
E botsitsoe : boiteko (W) ?
Jawab :
Taba ea pele, bala sebaka se tsamailoeng u sebelisa foromo ea GLBB:
s = vo t + ½ ho2 = (0)(3) + ½ (2)(3)2
s = 0 + (1)(9) = 9
Mosebetsi o entsoeng tafoleng:
W = F s = (ma)(s) = (10)(2)(9) = 180 Joule
Karabo e nepahetseng ke D.
9 SBoloko bo boima ba 1,5 kg bo sutumelletsoa holimo ke matla a sa fetoheng F = 15 N sebakeng se sekametseng joalo ka ha ho bontšitsoe setšoantšong. Nka hore ho potlaka ka lebaka la matla a khoheli (g) ke 10 m/s.-2 'me khohlano pakeng tsa boloko le sefofane se sekametseng ke lefela. Mosebetsi oohle o entsoeng bolokong ke…
A. 15 J
B. 30 J
C. 35 J
D. 45 J
E. 50 J
Puisano
Hoa tsebahala :
Boima ba boloko (m) = 1,5 kg
Ho potlaka ka lebaka la matla a khoheli (g) = 10 m/s2
Boima ba boloko (w) = mg = (1,5)(10) = 15 Newton
Matla a ho sututsa (F) = 15 Newton
E botsitsoe : mosebetsi o felletseng o entsweng bolokong (W) ?
Jawab :
Ho na le matla a mabedi a sebetsang hodima boloko; matla a bapileng le ho falla ha boloko, e leng matla a ho sututsa (F) le boima ba boloko bo bapileng le bokahodimo ba sefofane se sekametseng (w).x).
Mosebetsi o etsoang ke matla a sututsang ke:
W1 = F s = (15 N)(2 m) = 30 N m = 30 Joule
Mosebetsi o entsoeng ke matla a khoheli:
W2 = wx s = (ha e le hantle 30o)(2 m) = (15 N)(1/2)(2 m) = 15 N m = 15 Joule
Kakaretso ea mosebetsi o entsoeng bolokong:
Wkakaretso = W.1 - W2 = 30 J – 15 J = 15 Joule
Karabo e nepahetseng ke A.