1. Cov ntsiab lus A thiab B yog 4 m thiab 9 m ntawm qhov chaw suab, raws li. Yog tias I A thiab I B yog qhov muaj zog ntawm cov ntsiab lus A thiab B, raws li , ces I A : I B yog…
A. 3: 2
B. 4: 9
C. 9: 4
D. 16: 81
E. 81: 16
Kev Sib Tham
1. Ib tug neeg saib kev sib tw tsheb hnov lub suab sib txawv (lub suab nrov ntawm lub tsheb) thaum cov tsheb los txog thiab thim rov qab. Lub tsheb sib tw nruab nrab tsim lub suab ntawm 800 Hz. Yog tias qhov ceev ntawm lub suab hauv huab cua yog 340 m / s,-1 thiab lub tsheb ceev yog 20 ms-1, ces qhov zaus hnov thaum lub tsheb los txog yog….
A. 805 Hz
B. 810 Hz
C. 815 Hz
D. 850 Hz
E. 875 Hz
Kev Sib Tham
1. QhaIb lub mos txwv roj hmab uas zoo li lub pob uas muaj qhov hnyav ntawm 40 grams raug tua kab rov tav mus rau ntawm phab ntsa raws li pom hauv daim duab. Yog tias lub pob dhia ntawm tib qhov ceev, ces qhov kev hloov pauv ntawm lub zog ntawm lub pob yog a
dalah…
A. 2 Ns
B. 3 Ns
C. 4 Ns
D. 5 Ns
E. 6 Ns
Kev Sib Tham
14 Piv txwv ntawm Cov Lus Nug Txog Doppler Effect
1. Los ntawm cov lus hauv qab no:
(1) P mus txog S uas yog qhov ruaj khov
(2) S mus txog P uas yog qhov ruaj khov
(3) P thiab S sib ze ua ke
(4) S thiab P txav mus rau tib qho ceev
Yog tias P (mloog) hnov suab nrog rau qhov zaus siab dua qhov zaus uas S (qhov chaw) tso tawm, ces cov lus tseeb yog ...
A. (1), (2) thiab (3) xwb
B. (1), (2), (3) thiab (4)
C. (1) thiab (3) xwb
D. (1) thiab (4) xwb
E. (2) thiab (4) xwb
Kev Sib Tham
1. Ob yam khoom A (3 kg) thiab B (5 kg) txav mus rau tib qho kev taw qhia nrog qhov ceev ntawm 8 ms -1 thiab 4 ms -1 raws li . Yog tias yam khoom A ntaus yam khoom B nrog qhov elasticity zoo meej, ces qhov ceev ntawm txhua yam khoom tom qab kev sib tsoo yog...
A. 3 ms –1 thiab 7 ms –1
B. 6 ms –1 thiab 10 ms –1
C. 4,25 ms –1 thiab 10 ms –1
D. 5,5 ms –1 thiab 5,5 ms –1
E. 8 ms –1 thiab 4 ms –1
Kev Sib Tham
1. Ib lub pob uas hnyav 0,5 kg poob dawb paug ntawm qhov siab h1 = 7,2 m saum hauv pem teb thiab dhia mus rau qhov siab h2 = 3,2 m. Yog tias qhov kev nrawm vim lub ntiajteb txawj nqus yog 10 ms -2 , lub zog ua rau lub pob yog...
A. 2,0 Ns
B. 3,0 Ns
C. 10 Ns
D. 40 Ns
E. 80 Ns
Kev Sib Tham
1. Saib daim duab hauv qab no ntawm qhov kev hloov chaw ntawm lub thaiv! Xav tias g = 10 m/s 2. Yog tias tus coefficient ntawm kev sib txhuam kinetic ntawm lub thaiv thiab hauv pem teb yog μ k = 0,5, ces tus nqi ntawm qhov kev hloov chaw ntawm cov khoom yog ....
A. 5,00 m
B. 4,25 m
C. 3,00 m
D. 2,50 m
E. 2,00 m
Kev Sib Tham
1. Siv 4.900 Joules ntawm lub zog los tsa ib yam khoom hnyav 50 kg ntsug. Yam khoom yuav nce mus txog qhov siab ntawm ... (g = 9,8 ms -2 )
A. 0,1 m
B. 10 m
C. 98 m
D. 245 m
E. 960 m
Kev Sib Tham
1. Lub zog tas li ntawm 60 N ua haujlwm rau 12 vib nas this rau ib yam khoom uas hnyav 10 kg. Lub khoom
muaj qhov ceev pib ntawm 6 m/sec nyob rau tib qho kev taw qhia li lub zog.
(1) Txoj haujlwm ua tiav rau ntawm yam khoom yog 30.240 joules
(2) Lub zog kinetic kawg ntawm cov khoom yog 30.240 joules.
(3) Lub zog tsim tawm yog 2.520 watts
(4) Qhov nce ntawm lub zog kinetic ntawm yam khoom yog 180 joules.
Cov lus tseeb yog...
1. Qhov piv ntawm cov pawg ntawm cov ntiaj teb A thiab B yog 2:3 thaum qhov piv ntawm lub vojvoog ntawm cov ntiaj teb A thiab B yog 1:2. Yog tias qhov hnyav ntawm ib yam khoom ntawm lub ntiaj teb A yog w, ces qhov hnyav ntawm yam khoom ntawm lub ntiaj teb B yog….
A. 3/8 w
B. 3/4 w
C. 1/2 w
D. 4/3 w
E. 8/3 w
Kev Sib Tham