10 Piv Txwv ntawm Cov Lus Nug Txog Kev Nyuaj Siab
1. Qhov hnyav thiab qhov ntim ntawm plaub lub blocks hauv qab no yog tib yam, yog li qhov siab me tshaj plaws rau hauv pem teb yog exerted los ntawm tus lej khoom ...
A. Kuv
B. II
C. III
D. IV
Kev Sib Tham
Cov mis siab:
P = F / A
Raws li cov qauv no, nws xaus lus tias lub siab (P) yog ncaj qha proportional rau lub zog (F) thiab inversely proportional rau thaj tsam ntawm qhov chaw (A). Qhov no txhais tau tias yog tias lub zog ntau dua, lub siab kuj loj dua, thiab yog tias thaj tsam ntawm qhov chaw loj dua, lub siab kuj me dua.
Raws li daim duab, thaj chaw loj tshaj plaws uas kov hauv pem teb yog yam khoom III yog li yam khoom no muaj qhov siab tsawg tshaj plaws rau hauv pem teb.
Cov lus teb yog C.
2. Yog tias qhov hnyav ntawm plaub lub duab peb ceg hauv qab no zoo ib yam, qhov siab tshaj plaws ntawm thaj chaw siab yog qhia los ntawm daim duab...
Kev Sib Tham
Cov mis siab:
P = F / A = w / A
Cov Ntaub Ntawv: P = siab, F = lub zog, w = lub ntiajteb txawj nqus, A = thaj chaw uas kov hauv pem teb.
Raws li cov qauv no, nws tuaj yeem xaus lus tias qhov siab yog ncaj qha rau lub ntiajteb txawj nqus thiab inversely proportional rau thaj chaw kov hauv pem teb. Yog li ntawd, qhov loj dua lub ntiajteb txawj nqus, qhov siab dua, thiab qhov me dua thaj chaw ntawm ib yam khoom kov hauv pem teb, qhov siab dua.
Yog tias qhov hnyav ntawm plaub lub duab peb ceg yog tib yam, ces lub zog ntawm lub ntiajteb txawj nqus ntawm plaub lub duab peb ceg yog tib yam. Yog li ntawd, qhov siab nyob ntawm thaj chaw uas kov hauv pem teb, qhov twg thaj chaw me tshaj plaws muaj qhov siab tshaj plaws.
Cov lus teb yog B.
3. Qhov siab tshaj plaws tau pom hauv daim duab ...
Kev Sib Tham
Cov mis siab:
P = F / A = w / A
Cov Ntaub Ntawv: P = siab, F = lub zog, w = lub ntiajteb txawj nqus, A = thaj chaw kov hauv pem teb.
Raws li cov qauv no, nws tuaj yeem xaus lus tias qhov siab yog ncaj qha rau lub ntiajteb txawj nqus thiab inversely proportional rau thaj chaw kov hauv pem teb. Yog li ntawd, qhov loj dua lub ntiajteb txawj nqus, qhov siab dua, thiab qhov me dua thaj chaw ntawm ib yam khoom kov hauv pem teb, qhov siab dua.
Yog tias qhov hnyav ntawm plaub yam khoom yog tib yam, ces lub zog ntawm lub ntiajteb txawj nqus rau ntawm plaub yam khoom yog tib yam. Yog li ntawd, qhov siab nyob ntawm thaj chaw uas kov hauv pem teb, qhov twg thaj chaw me tshaj plaws muaj qhov siab tshaj plaws.
Cov lus teb yog D.
4. Lub zog ntawm 500 N ua rau ntawm thaj chaw ntawm 2,5 m2 Lub siab ...
A. 20 Pa
B. 200 Pa
C. 2000 Pa
D. 2 Pa
Kev Sib Tham
Nws paub tias:
Lub zog (F) = 500 Newton
Thaj chaw nto (A) = 2,5 square meters
Nug: Siab (P)
Lus teb:
Siab (P):
P = F / A
P = 500 / 2,5
P = 200 N/m2
P = 200 Pascal
Cov lus teb yog B.
5. Lub zog ntawm 500 N ua rau ntawm thaj chaw ntawm 2,5 m2 Lub siab ...
A. 20 Pa
B. 200 Pa
C. 2000 Pa
D. 2 Pa
Kev Sib Tham
Nws paub tias:
Lub zog (F) = 500 Newton
Thaj chaw nto (A) = 2,5 square meters
Nug: Siab (P)
Lus teb:
Siab (P):
P = F / A
P = 500 / 2,5
P = 200 N/m2
P = 200 Pascal
Cov lus teb yog B.
6. Saib daim duab hauv qab no! Qhov hnyav ntawm lub thawv = 75 kg thiab qhov kev nrawm vim yog lub ntiajteb txawj nqus g = 10 m/s2Lub siab uas tawm los ntawm hauv qab ntawm lub thawv yog...
A. 150 N/m2
B. 125 N/m2
C. 75 N/m2
D. 25 N/m2
Kev Sib Tham
Nws paub tias:
Qhov hnyav ntawm lub thawv (m) = 75 kg
Kev nrawm vim lub ntiajteb txawj nqus (g) = 10 m/s2
Lub ntiajteb txawj nqus (w) = mg = (75 kg)(10 m/s)2) = 750 kg m/s2 = 750 Newtons
Thaj chaw ntawm lub hauv paus ntawm lub thawv (A) = 6 meters x 5 meters = 30 square meters
Nug: Lub siab uas tawm los ntawm hauv qab ntawm lub thawv
Lus teb:
Lub zog ntawm lub thawv hauv qab:
P = F/A = w/A = 750/30 = 25 N/m2
Cov lus teb yog D.
7. Ib lub thawv ntawv uas muaj txiv nkhaus taw loj li 24 kg thiab muab tso rau hauv pem teb thiab nws qhov loj me yog raws li pom hauv daim duab (g = 10 m/s).2). Qhov siab ntawm daim ntawv cardboard uas muab tso rau hauv pem teb yog….
A. 600 N/m2
B. 1000 N/m2
D. 2400 N/m2
Kev Sib Tham
Nws paub tias:
Qhov hnyav (m) = 24 kg
Kev nrawm vim lub ntiajteb txawj nqus (g) = 10 m/s2
Qhov hnyav (w) = mg = (24 kg)(10 m/s)2) = 240 kg m/s2 = 240 Newtons
Thaj chaw uas kov hauv pem teb (A) = 1 m x 0,4 m = 0,4 m2
Nug: Qhov siab ntawm daim ntawv cardboard ua rau hauv pem teb
Lus teb:
Cov mis siab:
P = F / A = w / A
Kev piav qhia txog tus qauv: P = siab, F = lub zog, w = lub ntiajteb txawj nqus, A = thaj chaw nto
Qhov siab ntawm daim ntawv cardboard ua rau hauv pem teb:
P = 240 N / 0,4 m2 = 600 N/m22
Cov lus teb yog lawm yog A.
8. Plaub lub blocks uas zoo ib yam li qub tau muab tso rau hauv tib lub plag tsev raws li qhia hauv daim duab. Qhov siab tshaj plaws uas hauv pem teb ntsib tau raws li qhia hauv daim duab...
Kev Sib Tham
Cov mis siab :
P = F / A = w / A
Cov Ntaub Ntawv: P = siab, F = lub zog, w = lub ntiajteb txawj nqus, A = thaj chaw saum npoo.
Raws li cov qauv ntsuas siab, nws xaus lus tias qhov siab yog proportional rau lub zog thiab inversely proportional rau thaj tsam ntawm qhov chaw. Lub zog ntau dua, qhov siab ntau dua. Thaj chaw ntawm qhov chaw loj dua, qhov siab qis dua.
Cov pawg ntawm cov blocks yog tib yam, yog li lawv qhov hnyav yog tib yam. Yog li ntawd, qhov ntau ntawm qhov siab hauv qhov teeb meem saum toj no yog txiav txim siab los ntawm thaj chaw sib cuag nrog hauv pem teb (cheeb tsam hauv paus). Qhov siab tshaj plaws uas hauv pem teb ntsib yog tshwm sim los ntawm lub block nrog thaj chaw hauv paus me tshaj plaws.
Thaj chaw ntawm lub thaiv A = (2 cm)(4 cm) = 8 cm2
Thaj chaw ntawm thaiv B = (4 cm)(4 cm) = 16 cm2
Thaj chaw ntawm thaiv C = (4 cm)(3 cm) = 12 cm2
Thaj chaw ntawm lub voos xwmfab D = (3 cm)(3 cm) = 9 cm2
Cov lus teb yog lawm yog A.
9. Plaub lub pob zeb uas muaj tib lub cev hnyav tau muab tso rau hauv tib lub plag tsev. Lub pob zeb uas muaj zog tsawg tshaj plaws rau hauv pem teb yog...
Kev Sib Tham
Cov pawg ntawm cov blocks yog tib yam, yog li lawv qhov hnyav yog tib yam. Yog li ntawd, qhov ntau ntawm lub siab hauv qhov teeb meem saum toj no yog txiav txim siab los ntawm thaj chaw ntawm lub block hauv kev sib cuag nrog hauv pem teb (cheeb tsam hauv paus). Lub siab me tshaj plaws uas tau ntsib los ntawm hauv pem teb yog tshwm sim los ntawm lub block nrog thaj chaw hauv paus loj tshaj plaws.
Thaj chaw ntawm lub thaiv A = (2 cm)(2 cm) = 4 cm2
Thaj chaw ntawm thaiv B = (1 cm)(3 cm) = 3 cm2
Thaj chaw ntawm thaiv C = (4 cm)(2 cm) = 8 cm2
Thaj chaw ntawm lub voos xwmfab D = (4 cm)(4 cm) = 16 cm2
Cov lus teb yog D.
10. Saib daim duab hauv qab no! Txhua lub thaiv muaj tib lub cev hnyav. Qhov siab me tshaj plaws ntawm qhov chaw nias yog nyob rau ntawm lub thaiv ...
Kev Sib Tham
Qhov hnyav ntawm cov blocks yog tib yam yog li qhov hnyav ntawm cov blocks yog tib yam. Lub zog me tshaj plaws ntawm lub dav hlau compressive yog txiav txim siab tias yog los ntawm lub beam uas muaj thaj chaw loj tshaj plaws.
Thaj chaw ntawm lub thaiv A = (4 cm)(2 cm) = 8 cm2
Thaj chaw ntawm thaiv B = (3 cm)(2 cm) = 6 cm2
Thaj chaw ntawm thaiv C = (4 cm)(1 cm) = 4 cm2
Thaj chaw ntawm lub voos xwmfab D = (2 cm)(2 cm) = 4 cm2
Cov lus teb yog lawm yog A.
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
