Mienzaniso yemibvunzo pamusoro peMechanical Energy

Mienzaniso mitanhatu yeMibvunzo yeSimba reMichina

Dzidziso yesimba rekushanda nemabasa emakanika

1. Tarisa mufananidzo unotevera wekusuduruka kwebhuroko! Ngatitii g = 10 m/s ² . Kana coefficient yekinetic friction pakati pebhuroko nepasi iri μ k = 0,5, saka kukosha kwekusuduruka kwechinhu kuri ….

A. 5,00 m

B. 4,25 m

C. 3,00 m

D. 2,50 m

E. 2,00 m

Kukurukurirana

Zvinozivikanwa kuti :

Kukweshana kwekinetic ( μ k) = 0,5

Huremu hwebhuroko (m) = 4 kg

Kukurumidza kunokonzerwa negiravhiti (g) = 10 m/s ²

Kurema kwebhuroko (w) = mg = (4)(10) = 40 Newton

Kana bhokisi riri pamusoro penzvimbo yakati sandara, simba rakajairika (N) = huremu (w) = 40 Newtons.

Kumhanya kwekutanga (v ₁ ) = 5 m/s

Kumhanya kwekupedzisira (v ₂ ) = 0 m/s

Akabvunzwa : kufambiswa kwezvinhu?

Mhinduro :

Dzidziso yesimba rekushanda-mechanical inoti basa (W) rinoitwa nesimba risingachengetedzeki rakaenzana nekuchinja kwesimba remuchina rechinhu kana simba rekupedzisira remuchina (EM ₂ ) - simba rekutanga remuchina (EM ₁ ). Kinetic friction isimba risingachengetedzeki uye simba rega risingachengetedzeki rinoshanda pablock isimba rekinetic friction.

W = Δ EM

f _k s = EM ₂ – EM ₁

Basa rinoitwa ne kinetic friction:

W = f _ks = ( μ k )(N)(s) = (0,5)(40)(s) = 20 s

Kuchinja kwesimba remakanika:

EM = EM ₂ – EM ₁ = (EK + EP) ₂ – (EK + EP) ₁

Chinhu chinofamba pamusoro penzvimbo yakati sandara uye hachioni shanduko mukukwirira ( Δ h = 0) saka hapana shanduko musimba regiravhiti ( Δ EP = EP ₂ - EP ₁ = 0). Saka shanduko musimba remakanika dzinosanganisira chete shanduko musimba rekinetic.

Δ EM = EK ₂ – EK ₁ = ½ mv ₂ ² – ½ mv ₁ ² = ½ m (v ₂ ² – v ₁ ² )

EM = ½ (4) (0 ² – 5 ² ) = (2) (25) = 50

Kutamiswa kwebhuroko ndekwekuti:

W = Δ EM

masekondi makumi maviri = makumi mashanu

s = 50 / 20 = mamita makumi maviri nemashanu

Mhinduro chaiyo ndiD.

Mutemo wekuchengetedza simba remakanika

2. Zvinhu A naB zvine huremu hwakafanana. Chinhu A chinodonha kubva pakukwirira kwemamita h uye B chinodonha kubva pamamita maviri. Kana A ikarova pasi nekumhanya kwevm/s, ipapo chinhu B chinorova pasi nesimba rekinetic re….

A. 2 mv ²

B. mv ²

C. 3/4 mv ²

D. 1/2 mv ²

E. 1/4 mv ²

Kukurukurirana

Kumhanya kwekupedzisira kwechinhu B kunodonha zvakasununguka kubva pakukwirira kwemaawa maviri ndekwekuti:

v ² = 2 g (2h) = 4 gh

Simba rekinetic rechinhu B nderinotevera:

EK _B = ½ mv ² = ½ m (4 gh) = 2 mgh —– Equation 1

Simba rekutanga remuchina rechinhu B isimba regiravhiti = mg h. Simba rekupedzisira remuchina rechinhu B isimba remuchina = ½ mv ².

Mutemo wekuchengetedza simba remakanika :

mgh = ½ mv ².

Sezvo mgh = ½ mv ² saka tinogona kutsiva mgh mu equation 1 ne ½ mv ².

Simba reKinetic rechinhu B = 2 mgh = 2(½ mv ² ) = mv ²

Mhinduro chaiyo ndeiyi B.

3. Tarisa mufananidzo uri pazasi! Chinhu chinodonha zvakasununguka kubva pakukwirira kwemamita makumi maviri. Kana kukurumidza kunokonzerwa negiravhiti kuri 10 m/s, saka kumhanya kwechinhu chacho kana chiri pamusoro pevhu mamita gumi nemashanu….

A. 2 m/s

B. 5 m/s

C. 10 m/s

D. 15 m/s

E. 20 m/s

Kukurukurirana

Simba rekupedzisira remakanika = simba rekutanga remakanika

Simba remagetsi rechinhu chiri panhamba 2 = kuderedzwa kwesimba regiravhiti nemamita mashanu

½ mv ² = mgh

½ v ² = (10)(20-15)

½ v ² = (10)(5)

½ v ² = 50

v ² = (2)(50)

v ² = 100

v = 10 m/s

Mhinduro chaiyo ndiC.

4. Bhokisi rinobatwa pamusoro penzvimbo yakatsamira sezvakaratidzwa mumufananidzo. Kana raburitswa, bhokisi rinotsvedza risingakweshe richitevedza nzvimbo yakatsamira. Kumhanya kwebhokisi parinosvika pasi penzvimbo yakatsamira ndiko…

A. 6 ms^-1

B. 8 ms ^-1

C. 10 ms ^-1

D. 12 ms ^-1

E. 16 ms ^-1

Kukurukurirana

Simba rekutanga remakanika = simba rekukwevera pasi = mgh = m (10)(5) = 50 m

Simba remagetsi rekupedzisira = simba remagetsi = 1/2 mv ²

Mutemo wekuchengetedza simba remakanika unotaura kuti simba rekutanga remakanika = simba rekupedzisira remakanika.

EM _o = EM _t

50 m = 1/2 mv ²

50 = 1/2 v ²

2 (50) = v ²

100 = v ²

v = 10 m/s

Mhinduro chaiyo ndiC.

5. Bhokisi rine huremu hwe m kg rinoburitswa kubva pakakwirira kwemamita h pamusoro pevhu sezvakaratidzwa mumufananidzo. Chiyero chesimba rinogona kumuka (EP) uye simba rekinetic (EK) kana riri panzvimbo ye M….

A. 1: 3

B. 1: 2

C. 2 : 1

D. 2: 5

Chikamu 3: 7

Kukurukurirana

Simba rekukwevera pasi panzvimbo M:

EP _M = mg (0,3 maawa)

Simba reKinetic panzvimbo M = kuderedzwa kwesimba regiravhiti ne h-0,3h = 0,7h

EK _M = EP = mg (0,7 maawa)

Chiyero chesimba regiravhiti uye simba rekinetic panzvimbo yeM ndeichi:

EP _M : EK _M

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

0,3: 0,7

3: 7

Mhinduro chaiyo ndiE.

6. Tarisa mufananidzo wechinhu A chichidonha zvakasununguka kubva panzvimbo P iri pazasi!

Kana EP _Q na EK _Q zviri simba rinogona kugoneka uye simba rekinetic panzvimbo Q zvichiteerana (g = 10 m/s ² ), saka EP _Q : EK _Q ndiyo….

A. 16: 9

B. 9: 16

C. 3 : 2

D. 2: 3

Chikamu 2: 1

Kukurukurirana

Simba resimba rinokwevera pasi padanho reQ:

EP _Q = mgh = (m)(10)(1,8) = 18 m

Simba reKinetic padanho Q = kuderedzwa kwesimba regiravhiti ne5-1,8 = 3,2 metres

EK _Q = EP = mgh = m (10)(3,2) = 32 m

Chiyero chesimba regiravhiti uye simba rekinetic panzvimbo yeQ ndeichi:

EP _Q : EK _Q

18 m : 32 m

18: 32

9: 16

Kwakabva mubvunzo:

Mibvunzo yeNational Examination Physics yeChikoro Chesekondari/Chikoro Chepamusoro Chebasa