Mehlala e 4 ea lipotso tsa sefofane se sekametseng ho SMP
1. Sheba setšoantšo se latelang!
Teraka e boima ba 10 N e huloa ho tloha tlase ho sefofane se sekametseng ho ya hodimo ho sefofane se sekametseng. Boholo ba matla a hlokahalang F ke…
A. 15,0 N
B. 12,5 N
C. 5,0 N
D. 2,5 N
Puisano
Hoa tsebahala hore:
Boima ba teroli (w) = 10 Newton
Bolelele ba sefofane se sekametseng = limithara tse 2
Bophahamo ba sefofane se sekametseng = limithara tse 0,5
θ = sekhutlo pakeng tsa sefofane se bataletseng le sefofane se sekametseng
Sebe θ = 0,5/2 = 0,25
Potso: Boholo ba matla F
Karabo:
w x ke karolo ea boima ba teroli e bapileng le sefofane se sekametseng
w ke karolo ea boima ba teroli e otlolohileng ho sefofane se sekametseng
E le hore teroli e huloe holimo, matla a ho hula F a tlameha ho lekana bonyane le w x.
w x = w sin θ = (10 Newton)(0,25) = 2,5 Newton
Kahoo matla a ho tsikinyeha F = 2,5 Newton
Karabo e nepahetseng ke D.
2.
Ntho e entsoeng ka boloko bo boreleli ba lepolanka e tla phahamisoa sebakeng se sekametseng boreledi joalo ka ha ho bontšitsoe setšoantšong. Haeba boima ba boloko e le 6 kg, g = 10 m/s2, joale boholo ba matla a sutumetsang ho phahamisa boloko ho tloha ho P ho ea ho Q ke…
A. 36 Newton
B. 24 Newton
C. 20 Newton
D. 12 Newton
Puisano
Berat lehlaseli: w = mg = (6)(10) = 60 kg m/s2 = 60 Newton
Liboloko tse boreleli le mahlakore a sekametseng li boreleli kahoo ho nkoa hore ha li na khohlano. gesekanE le hore boloko bo ka isoa holimo, matla a fokolang a ho sutumelletsa a tlameha ho lekana le karolo ea boima ba boloko bo bapileng le sefofane se sekametseng, e leng wx.
wx = w sin teta = (w)(lehlakore le ka pele/hypotenuse)
wx = (60)(20/60) = (60)(1/3) = 20 Newtons
Karabo e nepahetseng ke C.
3.
Mosebetsi o batla ho isa lebokose terakeng e boima ba di-Newton tse 500 a sebedisa sefofane se sekametseng jwalo ka ha ho bontshitswe setshwantshong se ka tlase. Haeba teraka e le bolelele ba 1,5 m, ho hlokahala matla a makae ho tsamaisa lebokose?
A. 125 N
B. 250 N
C. 500 N
D. 1500 N
Puisano
Boima ba lebokose (w) = 500 Newton
E le hore lebokose le ka isoa holimo, matla a fokolang a ho sutumelletsa a tlameha ho tšoana le karolo ea matla a khoheli a lebokose a bapileng le sefofane se sekametseng, e leng wx.
wx = w sin teta = (w)(lehlakore le ka pele/hypotenuse)
wx = (500)(1,5/3) = (500)(1/2) = 250 Newtons
Karabo e nepahetseng ke B.
4.
Sesebelisoa se boima se lokela ho phahamisoa ho sebelisoa polanka e sekametseng, joalo ka ha ho bontšitsoe setšoantšong se latelang. Ho netefatsa hore matla a ho phahamisa a halofo ea boima ba 'nete ba kreiti, polanka e bolelele ba...
A. 5,0 m
B. 7,5 m
C. 10,0 m
D. 12,5 m
Puisano
Boima ba lebokose = w
E le hore lebokose le ka isoa holimo, matla a fokolang a ho sutumelletsa a tlameha ho lekana le karolo ea matla a khoheli a lebokose a bapileng le sefofane se sekametseng, e leng wx. Kahoo boholo ba matla a sututsang bo feta boima ba lebokose ka makhetlo a 0,5, bolelele ba boto ke…
wx = w sin teta
wx = (w)(lehlakore le ka pele/hypotenuse)
0,5 (w)= (w)(2,5/x)
0,5 = (2,5/x)
x = 2,5/0,5 = limithara tse 5
Karabo e nepahetseng ke A.
Mohloli oa lipotso:
Lipotso tsa Tlhahlobo ea Naha ea Saense ea Sekolo se Phahameng sa Bana ba Banyenyane/Sekolo se Phahameng sa Boislamo
