Imibuzo eyisibonelo mayelana ne-Mechanical Energy

Izibonelo Ezi-6 Zemibuzo Yamandla Emishini

Ithiyori yomsebenzi-wamandla wemishini

1. Naka isithombe ukufuduka vimba kanje! Cabanga ukuthi g = 10 m/s²Uma i-coefficient yokungqubuzana kwe-kinetic phakathi kwebhulokhi kanye nephansi μk = 0,5, khona-ke inani lokufuduka kwento lingu- ….

A. 5,00 m

B. 4,25 m

C. 3,00 m

D. 2,50 m

E. 2,00 m

Ingxoxo

I-Diketahui :

I-coefficient yokungqubuzana kwe-kinetic (μk) = 0,5

Isisindo sebhulokhi (m) = 4 kg

Ukusheshisa ngenxa yamandla adonsela phansi (g) = 10 m/s²

Isisindo sebhulokhi (w) = mg = (4)(10) = 40 Newton

Uma ibhloko lisesicaba, khona-ke amandla avamile (N) = isisindo (w) = amaNewton angu-40.

Ijubane lokuqala (v)₁) = 5 m/s

Ijubane lokugcina (v)₂) = 0 m/s

Kubuziwe : ukufuduka kwezinto (izinto)?

Jawab :

Ithiyori yamandla okusebenza-okusebenza ithi umsebenzi (W) owenziwa amandla angewona awokugcina ulingana noshintsho emandleni okusebenza ento noma emandleni okugcina okusebenza (EM).₂) – amandla okuqala omshini (EM)₁). Ukungqubuzana kwe-kinetic kungamandla angewona awokugcina futhi amandla angewona awokugcina asebenza ebhulokini ukungqubuzana kwe-kinetic.

W= ΔEM

f_k s = EM₂ – I-EM₁

Umsebenzi owenziwe nge-kinetic friction:

W = f_k s = (μk)(N)(s) = (0,5)(40)(s) = 20 s

Izinguquko emandleni omshini:

ΔI-EM = I-EM₂ – I-EM₁ = (EK + EP)₂ – (EK + EP)₁

Izinto zihamba endaweni eyisicaba futhi aziboni izinguquko ekuphakameni (Δh = 0) ngakho-ke akukho ushintsho emandleni adonsela phansi (ΔI-EP = I-EP₂ – EP₁ = 0). Ngakho-ke ushintsho lwamandla omshini luhilela kuphela ushintsho lwamandla okunyakaza.

ΔEM = EK₂ – EK₁ = ½ mv₂² – ½ mv₁² = ½ m (v₂² - v₁²)

ΔI-EM = ½ (4)(0² - 5²) = (2)(25) = 50

Ukufuduka kwebhulokhi yilokhu:

W= ΔEM

Amasekhondi angu-20 = 50

s = 50 / 20 = amamitha angu-2,5

Impendulo efanele ngu-D.

Umthetho wokulondolozwa kwamandla emishini

2. Izinto u-A no-B zinesisindo esifanayo. Into u-A iwela kusuka ekuphakameni kwamamitha angu-h kanti u-B uwela kusuka kumamitha angu-2. Uma u-A eshaya phansi ngesivinini se-vm/s, khona-ke into u-B izoshaya phansi ngamandla e-kinetic angu….

A. 2 mv²

B. mv²

C. 3/4 mv²

D. 1/2 mv²

E. 1/4 mv²

Ingxoxo

Isivinini sokugcina sento B esiwela ngokukhululeka sisuka ekuphakameni kwamahora ama-2 yilesi:

v² = 2 g (amahora ama-2) = 4 gh

Amandla e-kinetic ento B yilawa:

EK_B = ½ mv² = ½ m (4 gh) = 2 mgh —– Isibalo 1

Amandla okuqala omshini ento B amandla adonsela phansi = mg h. Amandla okugcina omshini ento B amandla omshini = ½ mv².

Umthetho wokulondolozwa kwamandla emishini :

mgh = ½ mv².

UKarena mgh = ½ mv² bese singashintsha i-mgh ku-equation 1 nge-½ mv².

Amandla e-kinetic ento B = 2 mgh = 2(½ mv)²) = mv²

Impendulo efanele ingu-B.

3. Bheka isithombe esingezansi! Into iwela ngokukhululeka isuka ekuphakameni okungamamitha angu-20. Uma ukusheshisa okubangelwa amandla adonsela phansi kungu-10 m/s, khona-ke ijubane lento uma ingaphezu komhlabathi ngamamitha angu-15 li….

A. 2 m/s

B. 5 m/s

C. 10 m/s

D. 15 m/s

E. 20 m/s

Ingxoxo

Amandla okugcina omshini = amandla okuqala omshini

Amandla e-kinetic ento ephuzwini lesi-2 = ukwehla kwamandla adonsela phansi ngamamitha ama-5

½ mv² = mgh

½ v² = (10)(20-15)

½ v² = (10)(5)

½ v² = 50

v² = (2)(50)

v² = 100

v = 10 m/s

Impendulo efanele ngu-C.

4. Ibhulokhi libanjwe phezulu kwendiza ethambekele njengoba kuboniswe esithombeni. Uma likhishwa, ibhulokhi lishelela ngaphandle kokushayisana eduze kokwenyuka. Isivinini sebhulokhi uma sifika phansi kokwenyuka…

A. 6 ms^-1

B. 8 ms^-1

C. 10 ms^-1

D. 12 ms^-1

E. 16 ms^-1

Ingxoxo

Amandla okuqala omshini = amandla adonsela phansi = mgh = m (10)(5) = 50 m

Amandla okugcina omshini = amandla e-kinetic = 1/2 mv²

Umthetho wokulondolozwa kwamandla omshini uthi amandla okuqala omshini = amandla okugcina omshini.

EM_o = I-EM_t

50 m = 1/2 mv²

50 = 1/2 v²

2 (50) = v²

100 = v²

v = 10 m/s

Impendulo efanele ngu-C.

5. Ibhulokhi enesisindo esingu-m kg ikhishwa ekuphakameni kwamamitha angu-h ngaphezu komhlabathi njengoba kuboniswe esithombeni. Isilinganiso samandla angase abe khona (EP) kanye namandla e-kinetic (EK) uma sisephuzwini elingu-M….

A. 1: 3

B. 1: 2

C. 2: 1

D. 2: 5

Isahluko 3: 7

Ingxoxo

Amandla adonsela phansi endaweni M:

EP_M = mg (amahora angu-0,3)

Amandla e-kinetic endaweni ethi M = ukwehla kwamandla adonsela phansi ngo-h-0,3h = 0,7h

EK_M = EP = mg (amahora angu-0,7)

Isilinganiso samandla adonsela phansi kanye namandla e-kinetic endaweni ethi M yilesi:

EP_M : EK_M

mg (0,3 h): mg (0,7 h)

0,3: 0,7

3: 7

Impendulo efanele ngu-E.

6. Bheka isithombe sento A iwela ngokukhululeka kusuka endaweni P ngezansi!

Uma i-EP_Q kanye ne-EK_Q ngalinye liyi-potential energy kanye ne-kinetic energy endaweni ethi Q (g = 10 m/s²), bese kuba yi-EP_Q : EK_Q kuyinto….

A. 16: 9

B. 9: 16

C. 3: 2

D. 2: 3

Isahluko 2: 1

Ingxoxo

Amandla adonsela phansi endaweni ethi Q:

EP_Q = mgh = (m)(10)(1,8) = 18 m

Amandla e-kinetic endaweni ethi Q = ukwehla kwamandla adonsela phansi ngo-5-1,8 = amamitha angu-3,2

EK_Q = EP = mgh = m (10)(3,2) = 32 m

Isilinganiso samandla adonsela phansi kanye namandla e-kinetic endaweni ethi Q yilesi:

EP_Q : EK_Q

18 m : 32 m

18: 32

9: 16

Umthombo wombuzo:

Imibuzo Yefiziksi Yezivivinyo Zikazwelonke Zesikole Samabanga Aphezulu/Isikole Samabanga Aphezulu Sokufundela Umsebenzi