7 Cov Lus Nug Lag luam
1. Saib daim duab hauv qab no!
Tus nqi ntawm cov haujlwm ua tiav ntawm lub block yog ...
A. 3 Joule
B. 8 Joule
C. 16 Joule
D. 48 Joule
Kev Sib Tham
Nws paub tias:
Lub zog (F) = 12 Newton
Kev Hloov Chaw (s) = 4 meters
Nug: Lag Luam (W)
Lus teb:
Hauv daim duab saum toj no, qhov kev hloov chaw ntawm yam khoom yog nyob rau tib qho kev taw qhia nrog lub zog. Cov qauv ua haujlwm rau qhov xwm txheej no yog:
W = F s = (12 Newton)(4 meters) = 48 Newton meters = 48 Joules
Cov lus teb yog D.
2. QhaIb lub thaiv ntoo raug thawb nrog lub zog ntawm 200 N kom nws txav mus deb ntawm 2 m, txoj haujlwm ua los ntawm lub thaiv ntoo yog ...
A. 20 J
B. 100 J
C. 200 J
D. 400 J
Kev Sib Tham
Nws paub tias:
Lub zog (F) = 200 Newton
Kev Hloov Chaw (s) = 2 meters
Nug: Lag Luam (W)
Lus teb:
Lag Luam:
W = F s
W = (200 Newton) (2 meters)
W = 400 Newton meters
W = 400 Joule
Cov lus teb yog D.
3. Saib daim duab!
Ib tug neeg tsav tsheb sedan xav nres nws lub tsheb kom deb li ntawm 0,5 m ntawm lub tsheb thauj khoom uas thaum xub thawj nyob deb li ntawm 10 m ntawm lub tsheb sedan. Lub tsheb sedan yuav siv zog npaum li cas?
A. 525 J
B. 500 J
C. 495 J
D. 475 J
Kev Sib Tham
Nws paub tias:
Kev Hloov Chaw (s) = 10 meters – 0,5 meters = 9,5 meters
Lub zog (F) = 50 Newton
Nug: Lag Luam (W)
Lus teb:
Cov qauv ua lag luam:
W = F s
W = (50 Newton) (9,5 meters)
W = 475 Newton meters
W = 475 Joule
Cov lus teb yog D.
4. Saib daim duab!
Qhov kev siv zog uas Andi thiab Toni tau ua los txav lub tsheb mus 4 meters yog tias lub zog ntawm ob tug menyuam yog 50 N thiab 70 N feem yog...
A. 80 joules
B. 200 joules
C. 280 joules
D. 480 joules
Kev Sib Tham
Nws paub tias:
Kev Hloov Chaw (s) = 4 meters
Lub zog tshwm sim (F) = 50 Newtons + 70 Newtons = 120 Newtons
Nug: Lag Luam (W)
Lus teb:
Lag Luam:
W = F s = (120 Newton)(4 meters) = 480 Newton meters = 480 Joules
Cov lus teb yog D.
5. Ib tug neeg tsav tsheb rub lub tsheb uas nres lawm raws li pom hauv daim duab, kom lub tsheb txav mus deb li 1.000 cm. Qhov ntau ntawm cov haujlwm ua tiav yog…..
A. 250 Joule
B. 1.000 Joule
C. 2.500 Joule
D. 250.000 Joule
Kev Sib Tham
Nws paub tias:
Qhia txog txhua chav nyob hauv International System
Lub zog (F) = 250 Newton
Kev Hloov Chaw (s) = 1000 cm = 1000/100 meters = 10 meters
Nug: Qhov ntau ntawm kev siv zog (W)
Lus teb:
Cov qauv ua lag luam:
W = F s = (250 Newton)(10 meters) = 2500 Newton meters = 2500 Joules
Cov lus teb yog C.
6. Saib daim duab hauv qab no txog kev txav ntawm cov khoom!
JYog tias txoj haujlwm ua los ntawm cov zog no rau ntawm ib yam khoom yog 375 Joules, yam khoom tuaj yeem txav mus deb ...
A. 7,5 meters
B. 15 meters
C. 22,5 meters
D. 25 meters
Kev Sib Tham
Nws paub tias:
Ua Haujlwm (W) = 375 Joules
Lub zog tshwm sim (ΣF) = 40 N + 10 N – 25 N = 25 Newtons (mus rau sab xis)
Nug: Kev Hloov Chaw (cov)
Lus teb:
Cov qauv ua lag luam:
W = F s
Kev Hloov Chaw:
s = W / F = 375 Joules / 25 Newtons
s = 15 meters
Cov lus teb yog B.
7. Cov dej num ntawm qee tus menyuam hauv qab no yog Tsis yog ua lag luam yog…
A. thawb lub laub nqaij pob 10 meters
B. thawb lub tsheb uas nres kom txog thaum nws txav mus
C. thawb phab ntsa khov kho kom txog thaum koj hws
D. Caij tsheb kauj vab los ntawm tsev mus rau tsev kawm ntawv
Kev Sib Tham
Cov qauv ua lag luam:
W = ΣF s
Cov Ntaub Ntawv: W = kev siv zog lossis kev ua haujlwm, F = lub zog, s = kev hloov chaw
Raws li cov qauv saum toj no, muaj kev ua haujlwm yog tias muaj lub zog thiab muaj kev hloov chaw (muaj kev txav chaw).
Cov lus teb yog C.
Qhov chaw nug lus:
Cov Lus Nug Txog Kev Xeem Thoob Tebchaws ntawm Tsev Kawm Ntawv Theem Nrab Qib Siab/Islamic Tsev Kawm Ntawv Theem Nrab Qib Siab Science
