1. Umuntu onesisindo esingama-50 kg ekheshini. Ukusheshisa ngenxa yamandla adonsela phansi = 10 m/s 2 . Thola amandla avamile asetshenziswa entweni yikheshi, uma:
(a) ilifti iphumule
(b) ilifti yehla ngesivinini esingaguquki
(c) ilifti esheshiswa phezulu ngokusheshiswa okungaguquki 5 / s 2
(d) ilifti esheshiswa yehla ngesivinini esingaguquki esingu-5 m/s 2
(e) ilifti ekuweni okukhululekile
Isixazululo
Kwaziwa:
Isisindo somuntu (m) = 50 kg
Ukusheshisa ngenxa yamandla adonsela phansi (g) = 10 m/s 2
Isisindo (w) = mg = (50)(10) = 500 amaNewton
Okufunwayo: Amandla avamile (N)
Isixazululo:
(a) ilifti iphumule
Ilifti iphumule ngakho akukho ukusheshisa (a = 0)
Sikhetha indlela eya phezulu ngendlela eyakhayo kanye nendlela eya phansi ngendlela engemihle.
Σ F = ma
N – w = 0
N = w
N = 500 Newton
(b) ilifti yehla ngesivinini esingaguquki
Ijubane eliqhubekayo ukuze kungabikho ukusheshisa (a = 0)
Sikhetha indlela eya phezulu ngendlela eyakhayo kanye nendlela eya phansi ngendlela engemihle.
Σ F = ma
N – w = 0
N = w
N = 500 Newton
(c) ilifti esheshiswa phezulu ngesivinini esingaguquki esingu-5 m/s 2
Isiqondiso sokusheshisa siphezulu, ngakho-ke sikhetha isiqondiso esihle njengesiphezulu.
N – w = ma
N = w + ma
N = 500 + (50)(5)
N = 500 + 250
N = 750 Newton
Umuntu uzwa iphansi liphakama kakhulu kunalapho ilifti imile noma ihamba ngesivinini esingaguquki.
Uma umuntu emi esikalini, isikali sifunda ubukhulu bamandla aphansi asetshenziswa ngumuntu esikalini. Ngokomthetho wesithathu kaNewton, lokhu kulingana nobukhulu bamandla ajwayelekile aphezulu asetshenziswa yisikali kumuntu.
(d) ilifti esheshiswa yehla ngesivinini esingaguquki esingu-5 m/s 2
Indlela yokusheshisa ibheke phansi, ngakho-ke sikhetha indlela eyakhayo njengeyehlayo.
w – N = ma
N = w – ma
N = 500 – (50)(5)
N = 500 – 250
N = 250 Newton
Isisindo somuntu singama-250 N, ngaphansi kwesisindo sangempela w = 500 N.
(e) ilifti ekuweni okukhululekile
Ukuwa kwamahhala kusho ukuthi ukusheshisa kwe-lifti kufana nokusheshisa ngenxa yamandla adonsela phansi. Ubukhulu bokusheshisa ngenxa yamandla adonsela phansi bungu-9,8 m/s 2 , isiqondiso sayo sibheke phansi enkabeni yoMhlaba. Ijubane landa ngokulandelana ngesikhathi ngo-9,8 m/s phakathi nomzuzwana ngamunye.
Indlela yokusheshisa ibheke phansi, ngakho-ke sikhetha indlela eyakhayo njengeyehlayo.
w – N = ma
N = w – ma
N = 500 – (50)(10)
N = 500 – 500
N = 0
[irp]
2. Thola ukucindezeleka ekhebula le-lifti. Isisindo se-lifti = 2000 kg.
(a) ilifti iphumule
(b) ilifti esheshiswa yehla ngesivinini esingaguquki esingu-5 m/s 2
(c) ilifti esheshiswa phezulu ngesivinini esingaguquki esingu-5 m/s 2
(d) ilifti ekuweni okukhululekile
Ukusheshisa ngenxa yamandla adonsela phansi (g) = 10 m/s 2
Isixazululo
Kwaziwa:
Isisindo se-elevator (m) = 2000 kg
Ukusheshisa kwamandla adonsela phansi (g) = 10 m/s 2
isisindo (w) = mg = (2000)(10) = 20,000 amaNewton
Okufunwayo: Amandla okucindezela (T)
Isixazululo:
(a) ilifti iphumule
ilifti iphumule ngakho akukho ukusheshisa (a = 0)
Sikhetha indlela eya phezulu njengesiqondiso esihle kanye nendlela eya phansi njengesiqondiso esibi.
Σ F = ma
T – w = 0
T = w
T = 20,000 Newton
Ukucindezeleka kwekhebula (T) = isisindo se-elevator (w) = ama-Newton angu-20,000
(b) ilifti esheshiswa yehla ngesivinini esingaguquki esingu-5 m/s 2
Indlela yokusheshisa ibheke phansi, ngakho-ke sikhetha indlela eyakhayo njengeyehlayo.
w – T = ma
T = w – ma
T = 20,000 – (2000)(5)
T = 20,000 – 10,000
T = 10,000 Newton
c) ilifti isheshiswe phezulu ngesivinini esingaguquki esingu-5 m/s 2
Indlela yokusheshisa ibheke phansi, ngakho-ke sikhetha indlela enhle njengeyaphezulu.
T – w = ma
T = w + ma
T = 20,000 + (2000)(5)
T = 20,000 + 10,000
T = 30,000 Newton
(d) ilifti ekuweni okukhululekile
Indlela yokusheshisa ibheke phansi, ngakho-ke sikhetha indlela eyakhayo njengeyehlayo.
w – T = ma
T = w – ma
T = 20,000 – (2000)(10)
T = 20,000 – 20,000
T = 0
[wpdm_package id='482′]
- Isisindo kanye nesisindo
- amandla ajwayelekile
- Umthetho wesibili wokunyakaza kukaNewton
- Amandla okungqubuzana
- Ukunyakaza endaweni evundlile ngaphandle kwamandla okungqubuzana
- Ukunyakaza kwemizimba emibili ngokusheshisa okufanayo endaweni evundlile eqinile ngamandla okungqubuzana
- Ukunyakaza endizeni ethambekele ngaphandle kwamandla okungqubuzana
- Ukunyakaza endizeni ethambekele emangelengele ngamandla okungqubuzana
- Ukunyakaza e-lifti
- Ukunyakaza kwemizimba kuxhunywe ngezintambo nama-pulleys
- Imizimba emibili enesilinganiso esifanayo sokusheshisa
- Ukuzungeza ijika eliyisicaba - amandla okunyakaza okujikelezayo
- Ukuzungeza ijika eligobile - amandla okunyakaza okujikelezayo
- Ukunyakaza okufanayo kumbuthano ovundlile
- Amandla aphakathi ahambisanayo ajikelezayo
