1. A 500-grkuv yog ib yam khoom, A, txav mus rau ntawm 10 m / s thiab khoom 200-gram, B, txav mus rau 12 m/s. Cov khoom txav mus ze rau ib leeg thiab sib tsoo. Yog tias qhov ceev ntawm khoom A tom qab kev sib tsoo yog 6 m/s, qhov ceev ntawm yam khoom B tom qab sib tsoo yog dab tsi?
Paub:
Pawg ntawm yam khoom 1 (m1) = 500 grams = 0.5 kg
Pawg ntawm yam khoom 2 (m)2) = 200 grams = 0.2 kg
Initial tshaj tawm ntawm yam khoom 1 (v1) = -10 m/s
Qhov ceev pib ntawm yam khoom 2 (v2) = 12 m/s
Qhov ceev kawg ntawm yam khoom 1 (v1') = 6 m/s
Cov cim ntxiv thiab cov cim tsis qhia qhia tias cov khoom txav mus rau qhov sib txawv.
xav : qhov ceev kawg ntawm yam khoom 2 (v2')
Tshuaj:
m1 v1 +m2 v2 = kuv1 v1' + m2 v2'
(0.5)(-10)+(0.2)(12) = (0.5)(6)+(0.2)(v2')
-5 + 2.4 = 3 + 0.2 v2'
-2.6 = 3 + 0.2 v2'
-2.6 – 3 = 0.2 v2'
-5.6 = 0.2 v2'
v2' = -5.6 / 0.2
v2' = -28 m/s
Qhov ceev ntawm yam khoom 2 tom qab sib tsoo yog 28 m/s.
Cov cim ntxiv thiab rho tawm qhia tias cov khoom txav mus rau sab nraud.
2. Ob yam khoom sib npaug zos los ze rau ib leeg thiab sib tsoo. Qhov ceev ntawm yam khoom 1 yog 6 m/s thiab qhov ceev ntawm yam khoom 2 yog 8 m/s. Tom qab sib tsoo, yam khoom 2 txav mus rau sab laug nrog qhov ceev ntawm 5 m/s. Qhov loj thiab qhov kev coj ntawm qhov ceev ntawm yam khoom 1 yog dab tsi tom qab kev sib tsoo?
Paub:
Pawg ntawm yam khoom 1 (m)1) = m
Pawg ntawm yam khoom 2 (m2) = m
Qhov ceev pib ntawm yam khoom 1 (v1) = -6 m/s
qhov ceev pib ntawm yam khoom 2 (v2) = 8 m/s
Qhov ceev kawg ntawm yam khoom 2 (v2') = -5 m/s
xav : qhov loj thiab kev coj ntawm yam khoom 1 tom qab kev sib tsoo
Tshuaj:
Cov qauv ntawm kev txuag ntawm linear momentum :
m1 v1 +m2 v2 = kuv1 v1' + m2 v2'
mv1 +m v2 = kuv v1' + m v2'
m (v)1 +v2) = m(v)1' + v2')
v1 +v2 = v1' + v2'
-6 + 8 = v1' – 5
2 = v1' – 5
2 + 5 = v1'
v1' = 7 m/s
Qhov ceev ntawm yam khoom 1 tom qab sib tsoo (v1') is 3 XNUMXm/s.
Cov cim ntxiv thiab rho tawm qhia tias cov khoom txav mus rau sab nraud.
3. Lub pob 1-kg 1 thiab lub pob 2 2-kg muaj tib qho kev taw qhia thiab sib tsoo tsis sib luag. Ua ntej sib tsoo, lub pob 1 txav nrog qhov ceev ntawm 10 m/s thiab lub pob 2 txav nrog qhov ceev ntawm 5 m/s. Qhov ceev ntawm lub pob 2 tom qab sib tsoo yog 4 m/s. Txheeb xyuas qhov ceev ntawm lub pob 1 tom qab sib tsoo.
Paub:
Pawg Pob 1 (m)1) = 1 kg
Pawg Pob 2 (m)2) = 2 kg
Qhov ceev ntawm lub pob 1 (hauv1) = 10 m/s
Qhov ceev ntawm lub pob 2 (v2) = 5 m/s
Qhov ceev kawg ntawm lub pob 2 (v2') = 4 m/s
Lub cim ntxiv ntawm qhov ceev qhia tias cov pob muaj tib qho kev taw qhia.
xav : qhov ceev kawg ntawm lub pob 1 (v1')
Tshuaj:
m1 v1 +m2 v2 = kuv1 v1' + m2 v2'
(1)(10) + (2)(5) = (1)(v)1') + (2)(4)
10 + 10 = v1' + 8
20 – 8 = v1'
v1' = 12 m/s
Qhov ceev ntawm lub pob 1 tom qab sib tsoo yog 12 XNUMXm/s.
[wpdm_package id='1190′]
- Cov teeb meem thiab kev daws teeb meem ntawm linear momentum
- Cov teeb meem thiab kev daws teeb meem ntawm lub zog thiab lub zog txav mus los
- Kev sib tsoo zoo kawg nkaus hauv ib qho teeb meem thiab kev daws teeb meem
- Kev sib tsoo tsis sib xws hauv ib qho teeb meem thiab kev daws teeb meem
- Kev sib tsoo tsis sib xws hauv ib qho teeb meem thiab kev daws teeb meem
