Mienzaniso yemibvunzo pamusoro peMechanical Energy

Mienzaniso mitanhatu yeMibvunzo yeSimba reMichina

Dzidziso yesimba rekushanda nemabasa emakanika

1. Teerera mufananidzo wacho kudzingwa vhara seizvi! Ngatitii g = 10 m/s²Kana chiyero chekukakavadzana kwekinetic pakati pechivharo nepasi μk = 0,5, ipapo kukosha kwekutama kwechinhu (s) ndekwekuti ….

A. 5,00 m

B. 4,25 m

C. 3,00 m

D. 2,50 m

E. 2,00 m

Kukurukurirana

Zvinozivikanwa :

Kukweshana kwekinetic (μk) = 0,5

Huremu hwebhuroko (m) = 4 kg

Kukurumidza kunokonzerwa negiravhiti (g) = 10 m/s²

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 : kusuduruka kwechinhu (zvinhu)?

Jawab :

Dzidziso yesimba rekushanda-mechanical inoti basa (W) rinoitwa nesimba risingachengetedzi zvinhu rakaenzana nekuchinja kwesimba remagetsi rechinhu kana simba remagetsi rekupedzisira (EM).₂) – simba rekutanga remakanika (EM)₁). Kinetic friction isimba risingachengetedze uye simba risingachengetedze rinongoshanda pablock ndiyo kinetic friction.

W= ΔEM

f_k s = EM₂ - EM₁

Basa rinoitwa ne kinetic friction:

W = f_k s = (μk)(N)(s) = (0,5)(40)(s) = masekondi makumi maviri

Kuchinja kwesimba remakanika:

ΔEM = EM₂ - EM₁ = (EK + EP)₂ – (EK + EP)₁

Zvinhu zvinofamba panzvimbo yakati sandara uye hazvione kuchinja kwehurefu (Δh = 0) saka hapana shanduko musimba regiravhiti (ΔEP = EP₂ – EP₁ = 0). Saka shanduko musimba remakanika inosanganisira shanduko musimba rekinetic chete.

ΔEM = EK₂ - EK₁ = ½ mv₂² – ½ mv₁² = ½ m (v)₂² - v₁²)

ΔEM = ½ (4)(0² - 5²) = (2)(25) = 50

Kutamiswa kwebhuroko ndekwekuti:

W= ΔEM

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 re….

A. 2 mv²

B. mv²

C. 3/4 mv²

D. 1/2 mv²

E. 1/4 mv²

Kukurukurirana

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

v² = 2 g (maawa maviri) = 4 gh

Simba rekinetic rechinhu B nderinotevera:

EK_B = ½ mv² = 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 mv².

Mutemo wekuchengetedza simba remakanika :

mgh = ½ mv².

Nokuti mgh = ½ mv² tobva tatsiva mgh mu equation 1 ne ½ mv².

Simba reKinetic rechinhu B = 2 mgh = 2(½ mv)²) = mv²

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 mv² = mgh

½ v² = (10)(20-15)

½ v² = (10)(5)

½ v² = 50

v² = (2)(50)

v² = 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 mv²

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

EM_o = EM_t

50 m = 1/2 mv²

50 = 1/2 v²

2 (50) = v²

100 = v²

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 ndeche….

A. 1: 3

B. 1: 2

C. 2 : 1

D. 2: 5

Chikamu 3: 7

Kukurukurirana

Simba rekukwevera pasi panzvimbo M:

EP_M = mg (maawa 0,3)

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

EK_M = EP = mg (maawa 0,7)

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 uye EK_Q chimwe nechimwe ndicho simba rinogona kugoneka uye simba rekinetic panzvimbo Q (g = 10 m/s²), wobva waita EP_Q : EK_Q iri….

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