1. Lebelo la leqhubu le tsheletseng thapong ya dimithara tse 25 ke 50 m/s. Matla a kgatello ya thapo ke 200 N. Fumana boima ba thapo.
A. 0.08 kg
B. 0.5 kg
C. 0.8 kg
D. 2.0 kg
Tse tsejoang:
Bolelele ba thapo (l) = 25 m
Lebelo la leqhubu le ka hodimo (v) = 50 m/s
Matla a kgatello ya thapo (T) = 200 N
Ho batloa: Boima ba thapo (m)
Tharollo:
Bothata bona bo ka rarolloa ka ho sebedisa foromo ya foromo ya ho ata ha maqhubu thapong.
Karabo e nepahetseng ke D.
2. Holim'a letša ho phaphamala likotoana tse peli tsa patsi, sebaka se pakeng tsa tsona ke limithara tse 6. Maqhubu a ata holim'a letša. Ha patsi ea pele e se e ile holimo le tlase ka makhetlo a mararo, patsi ea bobeli e ile ea phahama le tlase hanngoe feela. Haeba metsotsoana e meng le e meng e 'meli mefuta eohle ea patsi e tsamaea holimo le tlase ka makhetlo a mararo, ho ata ha maqhubu ke ...
A. 4.5 m/s
B. 3.0 m/s
C. 2.0 m/s
D. 1.5 m/s
Tse tsejoang:
Sebaka se pakeng tsa meru ka bobeli (l) = limithara tse 6
Patsi ea pele e ile ea nyoloha le ho theoha ka makhetlo a mararo; patsi ea bobeli e ile ea nyoloha le ho theoha hanngoe feela.
Makgetlo (f) = 3 / 2 = 1.5 hertz
Ho batloa: Lebelo la leqhubu (v)
Tharollo:
Ha patsi ea pele e nyoloha le ho theoha hanngoe, bolelele ba leqhubu 1 bo ea lehong la bobeli. Ha patsi ea pele e nyoloha le ho theoha hanngoe, bolelele ba leqhubu 2 bo ea lehong la bobeli. Ha patsi ea pele e nyoloha le ho theoha hanngoe, bolelele ba leqhubu 2 bo ea lehong la bobeli. Ha patsi ea pele e nyoloha le ho theoha hanngoe hararo, bolelele ba leqhubu bo fihlile boemong ba lehong la bobeli, hoo ka nako e tšoanang patsi ea bobeli e nyolohang le ho theoha hanngoe.
Kahoo, ea distanta Pakeng tsa lehong la pele le lehong la bobeli ho na le maqhubu a mabeli a maqhubu (2 λ), joalo ka ha ho bontšitsoe setšoantšong se ka lehlakoreng.
Sebaka sa bolelele ba leqhubu la 1 (λ) = 6 / 2 = limithara tse 3
Lebelo la ho ata ha maqhubu (v):
v = f λ = (1.5 hertz)(3 limithara)
v = 4.5 m/s
Karabo e nepahetseng ke A.
3. Mabaka a potlakisang ho ata ha maqhubu hodima dithapo ke…
(1) atolosa terata
(2) ho holisa boima ba terata
(3) eketsa tsitsipano ea terata
(4) holisa boholo ba terata Polelo e nepahetseng ke…
A. (1), (2), (3) le (4)
B. (1), (2), le (3)
C. (3) le (4)
D. (3) feela
Tharollo:
Mokhoa oa lebelo la ho ata ha leqhubu likhoeleng:
Karabo e nepahetseng ke A.
v = lebelo la ho ata ha maqhubu likhoeleng
T = matla a tsitsipano a likhoele
μ = bongata ba khoele
m = boima ba khoele
l = bolelele ba khoele
4. Thapong e jala thapo ya bolelele ba leqhubu ka maqhubu a 50 Hz le bolelele ba leqhubu ba 2 m. Nako le lebelo la leqhubu ke…
A. Metsotsoana e 0.02 le 50 ms -1
B. Metsotsoana e 0.02 le 100 ms -1
C. metsotsoana e 0.04 le 50 ms -1
D. Metsotsoana e 0.5 le 100 ms -1
Tse tsejoang:
Maqhubu (f) = 50 Hz
Bolelele ba maqhubu (λ) = limithara tse 2
Ho batloa: Nako (T) le lebelo la leqhubu (v)
Tharollo:
Nako:
T = 1/f = 1/50 Hz = 0.02 metsotsoana
Lebelo la leqhubu:
v = f λ = (50 1/motsotsoana)(limithara tse 2) = limithara tse 100/motsotsoana
Karabo e nepahetseng ke B.
5. Sekoti se holim'a metsi se nyoloha le ho theoha ka lebaka la maqhubu a metsi a holim'a metsi. Nako e hlokahalang ho tloha holim'a metsi ho ea holim'a metsi ke metsotsoana e 1.2. Haeba holim'a metsi, sebaka se pakeng tsa li-crests tse peli ke 10 cm, joale fumana lebelo la ho ata ha maqhubu.
A. 12 ms -1
B. 12 cm s -1
C. 8,3 ms -1
D. 8,3 cm s -1
Tse tsejoang:
Nako e hlokahalang ho tloha karolong e ka holimo ho ea karolong e latelang ea bophahamo ba leqhubu = nako ea bolelele ba leqhubu le le leng = nako (T) = metsotsoana e 1.2.
Sebaka se pakeng tsa mafika a mabeli = sebaka sa bolelele ba leqhubu le le leng (λ) = 10 cm
Ho batloa: Lebelo la ho ata ha maqhubu (v)
Tharollo:
Lebelo la ho ata ha leqhubu:
v = f λ = λ / T = 10 cm / 1.2 metsotsoana = 8.3 cm/motsotswana = 8.3 cm.s -1
Karabo e nepahetseng ke D.
