Ukunyakaza kwamahhala kokuwa

Isihloko mayelana nokunyakaza kwe-Free Fall

Empilweni yansuku zonke, sivame ukubona izinto ezizwa ukunyakaza kokuwa, isibonelo, ukunyakaza kwesithelo esiwa esihlahleni, ukunyakaza kwezinto eziwa noma eziwa zisuka ekuphakameni okuthile. Kungani izinto zizwa ukunyakaza kokuwa ngokukhululekile? Uma kubhekwa ngokushesha, into izwa ukuwa ngokukhululekile njengokungathi inesivinini esinqunyiwe, noma ngamanye amazwi into ayisheshi. Iqiniso lokuthi kwenzeka, yonke into ewa ngokukhululekile izwa ukusheshisa okuqhubekayo. Lesi sizathu sibangela ukunyakaza kokuwa ngokukhululekile, okuhlanganisa nesibonelo sokunyakaza okuqondile okungafani. Indlela yokufakazela ukuthi izinto ezizwa ukuhlangenwe nakho kokuwa ngokukhululekile ukusheshisa okuqhubekayo noma ukwanda kwayo ngesivinini?

Faka izipikili ezimbili emhlabathini bese uphonsa itshe elivela endaweni ehlukile esipikilini ngasinye. Uzobona ukuthi izipikili ezifakwa amatshe ezingeni eliphakeme zinamathele kakhulu kunezinye izipikili. Uma indawo yetshe iphakeme kakhulu ebusweni bomhlaba, kulapho ijubane letshe likhula khona uma lishaya phansi ukuze licindezele isipikili ngokujulile.

Esikhathini esidlule, ukunyakaza kwezinto eziwela phansi kwakuyindaba ethakazelisayo kakhulu kwifilosofi yemvelo. U-Aristotle, isazi sefilosofi, wake wathi into enobunzima obukhulu iwela ngokushesha kunezinto ezilula. Umbono ka-Aristotle wathonya imibono yabantu abaphila ngaphambi kwesikhathi sikaGalileo, ababecabanga ukuthi izinto ezinobunzima obukhulu ziwela ngokushesha kunezinto ezilula nokuthi ijubane lezinto eziwela lalilingana nobunzima bento. Mhlawumbe ngaphambi kokufunda lesi sihloko, nawe ucabanga kanjalo. Isibonelo, siwisa iphepha nedwala kusukela ekuphakameni okufanayo. Imiphumela esiyibonile ibonise ukuthi itshe laqala lathinta umhlabathi noma phansi kunephepha. Manje, ake siwise amatshe amabili kusukela ekuphakameni okufanayo, lapho itshe elilodwa likhulu kunelinye. Amatshe amabili athinta ubuso bomhlaba ngesikhathi esifanayo, uma kuqhathaniswa netshe nephepha esaliwisa ngaphambili. Singazama futhi ngamatshe awela nephepha ngesimo sezigaxa.

Yini ethonya ukunyakaza kwamatshe noma iphepha eliwayo? Amandla okungqubuzana komoya! Ukumelana noma ukungqubuzana komoya kuthinta kakhulu ukunyakaza kokuwa okukhululekile. UGalileo wagomela ngokuthi zonke izinto zizowa ngokusheshisa okufanayo uma kungekho moya noma ezinye izithiyo. UGalileo wagomela ngokuthi zonke izinto, ezisindayo noma ezilula, ziwela ngokusheshisa okufanayo, okungenani uma kungekho moya. UGalileo wayekholelwa ukuthi umoya usebenza njengesithiyo ezintweni ezikhanya kakhulu ezinobuso obukhulu. Kodwa ezimweni eziningi, lokhu kumelana komoya kunganganakwa. Ekamelweni lapho umoya udonswe khona (i-vacuum), izinto ezikhanyayo njengephepha elibanjwe ngokuvundlile zizowa ngokusheshisa okufanayo nezinye izinto. Umnikelo kaGalileo ekuqondeni kwethu ukunyakaza kwezinto eziwayo ungafingqwa kanje:

Endaweni ethile emhlabeni futhi engenawo umoya oqinile, zonke izinto ziwela ngokusheshisa okufanayo okungaguquki. Lokhu sikubiza ngokuthi ukusheshisa okubangelwa amandla adonsela phansi futhi sikunike uphawu u-g. Ubukhulu buka-g bungaba ngu-9.8 m/s²Kumayunithi eSistimu yesiNgisi, ubukhulu buka-g bungaba ngu-32 ft/s². Isiqondiso sokusheshisa kwamandla adonsela phansi sibheke enkabeni yomhlaba.

Incazelo yokunyakaza kokuwa okukhululekile

Kuthiwa into ibhekana nokuwa okukhululekile uma into ihamba iqonde enkabeni yomhlaba futhi ngesikhathi sokunyakaza kwayo, into ihlangabezana nokusheshisa okungapheli kwamandla adonsela phansi. Uma ukuwa okukhululekile kuseduze nobuso bomhlaba, khona-ke into ihlangabezana nokusheshisa okungapheli kwamandla adonsela phansi angu-9.8 m/s²

kanye nesiqondiso sokusheshisa kwamandla adonsela phansi esiya enkabeni yomhlaba (eqondile ebusweni bomhlaba). Ukuze kube lula ukubala, i-g ingu-10 m/s².

Kunezimo ezintathu ezahlukene:

1. Izinto zihamba ziqonde phansi ngaphandle kwesivinini sokuqala (akukho v_o). Isibonelo, isithelo siyawa esihlahleni ngemva kokukhululwa esiqwini. Isiqondiso sokunyakaza sihlala sibheke phansi futhi into ihlangabezana nokusheshisa ukuze u-g ahlale ehle. Kwezinye izincwadi zefiziksi ezibizwa ngokuthi ukunyakaza kwe-free-fall.

2. Into ihamba iqonde phansi ngesivinini sokuqala (kukhona u-v_o). Isibonelo, itshe eliphonswa phansi liqonde phezulu. Isiqondiso sokunyakaza sihlala sibheke phansi futhi into ithola ukusheshisa ukuze u-g ahlale ehle. Ezincwadini ezithile zefiziksi, kubizwa ngokuthi ukunyakaza okuqonde phansi okuqondile.

3. Into ihamba iqonde phezulu ngesivinini sokuqala, ngemva kokufinyelela ukuphakama okuphezulu, into ibuyela phansi. Ake sithi uphonsa amamabula aqondile phezulu bese uwabamba futhi lapho amamabula ehla. Uma uhamba phezulu, izinto zithola ukwehla kwejubane (negative g), uma uhamba phansi ngejubane, into iyasheshisa (positive g). Ezincwadini ezithile zefiziksi, ibizwa ngokuthi ukunyakaza okuphezulu okuqondile. Kufanele kuqashelwe ukuthi uma into ihlangabezana nenye yezimo ezintathu ezingenhla, into kuthiwa yenza ukunyakaza kokuwa okukhululekile.

Isibalo sokunyakaza kokuwa kwamahhala

Ukunyakaza kwe-Free-fall kuyisibonelo sokunyakaza okuqondile okungafani, ngakho-ke i-equation yokunyakaza kwe-free-fall ifana kakhulu ne-equation yokunyakaza okuqondile okungafani futhi ilungiswe ngokwezimo zokunyakaza kwe-free-fall.

h = ukuphakama (amamitha), v_o = isivinini sokuqala (imitha/isekhondi), v_t = isivinini sokugcina (imitha/isekhondi), t = isikhathi (sesibili), g = ukusheshisa kwamandla adonsela phansi (imitha/isekhondi) = 9.8 m/s² noma 10 m/s².

Ukusheshisa kwamandla adonsela phansi kuhlala njalo ku-10 m/s² (u-g omuhle, into ihambela phansi) kusho ukuthi ijubane lento likhuphuka ngo-10 m/s njalo ngomzuzwana owodwa. Ngemva kwemizuzwana emi-2, ijubane lento likhuphuka ngo-20 m/s. Ngemva kwemizuzwana emi-3, ijubane lento likhuphuka ngo-30 m/s. Ukwehla okuqhubekayo kwamandla adonsela phansi kungu-10 m/s² (g negative, into inyukela phezulu) kusho ukuthi ijubane lento lehla ngo-10 m/s njalo ngomzuzwana owodwa. Ngemva kwemizuzwana emi-2, ijubane lento lehla ngo-20 m/s. Ngemva kwemizuzwana emi-3, ijubane lento lehla ngo-30 m/s. Ukusheshisa okuqhubekayo noma ukwehla okuqhubekayo kwenzeka kuphela eduze komhlaba.

Inkinga yesampula 1:

Umango uyadedelwa bese uwela phansi. Uma indawo yokuqala ingamamitha ayi-10 ukusuka ebusweni bomhlaba futhi isisindo sikamango singamagremu ama-5, thola:

(a) isivinini semango uma ifika phansi

(b) isikhathi lapho umango ufika phansi.

g = 9.8 m/s²

Isixazululo:

Kwaziwa: h = 10 m, g = 9.8 m/s²

a) Isivinini se-manga uma sifika phansi

Isisindo sibalwa ku-equation yokunyakaza kokuwa okukhululekile

b) Isikhathi esiphakathi emoyeni

Inkinga yesampula 2:

Into iwiswa isuka ekuphakameni okuthile. Thola:

(a) ubukhulu bokusheshisa kwento

(b) ibanga elihanjwe yinto imizuzwana emibili yokuqala

(c) isivinini sento ngemva kokuwa ngamamitha angu-50

(d) ukuthi singakanani isikhathi esidingekayo ukuze into ifinyelele isivinini esingama-20 m/s,

(e) isikhathi esingakanani esidingekayo ukuze into iwele kuze kufike kumamitha ayi-100

Isixazululo:

Kwaziwa: g = 9.8 m/s²

a) Ubukhulu bokusheshisa kwento

Ukusheshisa kwento = ukusheshisa kwamandla adonsela phansi = g = 9.8 m/s²

b) Ibanga elihanjwe yinto imizuzwana emibili yokuqala

Kwaziwa: g = 9.8 m/s² , t = 2 s

Okufunayo: h

h = 1⁄2 gt² = 1⁄2 (9.8)(2)² = (4.9)(4) = amamitha angu-19.6

c) Isivinini sento ngemva kokuwa kuze kufike kumamitha angu-50

Kwaziwa: h = 50 m, g = 9,8 m/s²

Okufunayo: v_t

d) Kudingeka isikhathi esingakanani ukuze izinto zifinyelele isivinini esingama-20 m/s

Kwaziwa: v_t = 20 m/s, g = 9,8 m/s²

Okufunayo: t

e) Isikhathi esidingekayo ukuze izinto ziwele kude kufike kumamitha ayi-100

Okufunayo: h = 100 m, g = 9,8 m/s²

Isixazululo: t

Inkinga yesampula 3:

Itshe liphonswa emthonjeni ngesivinini sokuqala esingu-5 m/s. Uma itshe liwela emanzini ngemva kwemizuzwana emi-4, thola:

(a) isivinini setshe uma lingena emanzini

(b) ukujula komthombo

Isixazululo:

a) Isivinini setshe uma lingena emanzini

Kwaziwa:

v_o = 5 m/s, t = 4 s, g = 9.8 m/s²

Okufunayo: v_t

v_t =v_o + gt

v_t = 5 m/s + (9.8 m/s²)(4 s) = 5 m/s + 39.2 m/s

v_t = 44.2m/s

b) Ukujula komthombo

Kwaziwa:

v_o = 5 m/s, t = 4 s, g = 9.8 m/s²

Okufunayo: h

h = v_o t + ½ gt²

h = (5)(4) + ½ (9.8)(4)²

h = 20 + (4.9)(16)

h = 20 + 78.4

h = amamitha angu-98.4

Inkinga yesampula 4:

Kusukela phezulu kwesakhiwo kuze kufike kumamitha angu-50, iphakethe liphonswa phansi liqonde phezulu ngesivinini esingu-10 m/s. Thola:

(a) Isikhathi emoyeni

(b) Isivinini sephakheji uma ishaya phansi

Isixazululo:

a) Isikhathi emoyeni

Kwaziwa:

h = 50 m, g = 9.8 m/s²e_o = 10m/s

Okufunayo: t

h = v_o t + ½ gt²

50 = 10 t + ½ (9.8) t²

50 = 10 t + 4.9 t²

I-4.9 t² + 10 t – 50 = 0

Sebenzisa ifomula ye-quadratic:

Isikhathi emoyeni = imizuzwana engu-2.3

b) Isivinini sephakheji uma ishaya phansi

Kwaziwa:

h = 50 m, g = 9.8 m/s²e_o = 10m/s

Okufunayo: v_t

Inkinga yesampula 5:

Ibhola liphonswa phezulu phezulu ngesivinini sokuqala esingu-20 m/s. Thola ukuphakama okuphezulu okufinyelelwe yibhola.

Isixazululo:

Ubuningi bevektha ebheke phezulu buyi-positive, ubuningi bevektha ebheke phansi buyi-negative. Indawo yokuqala yebhola ikhethwa njengendawo yokubhekisela.

Kwaziwa:

v_o = 20 m/s (isiqondiso sejubane lokuqala siphezulu, ibhola liphonswa phezulu, ngakho-ke v_o kuyinto enhle)

v_t = 0 m/s (isivinini sebhola ekuphakameni okuphezulu ngu-0 m/s)

g = – 9.8 m/s² (isiqondiso sokusheshisa kwamandla adonsela phansi siphansi, ngakho-ke u-g ungemuhle)

Okufunayo: h

Inkinga yesampula 6:

Imabula iphonswa phezulu isuka phezulu kwesakhiwo esingamamitha ayi-100 ngaphezu komhlabathi ngesivinini sokuqala esingu-20 m/s. Thola:

(a) Isikhathi emoyeni

(b) isivinini semabula uma ishaya phansi

Isixazululo:

Indawo lapho kuphonswa khona imabula njengendawo yokubhekisela; ingxenye ephezulu yesakhiwo yindawo yokubhekisela. Ubukhulu bevektha ebheke phezulu buyi-positive, ubukhulu bevektha ebheke phansi buyi-negative.

a) Isikhathi emoyeni

Kwaziwa:

h = – 100 m (h ayilungile ngoba ubuso bomhlaba bungaphansi kwesikhundla sokuqala noma iphuzu lokubhekisela)

v_o = 20 m/s (isiqondiso sejubane lokuqala siphezulu, ngakho-ke v_o kuyinto enhle)

g = – 9.8 m/s² (isiqondiso sokusheshisa kwamandla adonsela phansi siphansi, ngakho-ke u-g ungemuhle)

Okufunayo: t

Sebenzisa ifomula ye-quadratic:

Isikhathi esidingekayo ukuze kufike phansi kusukela

ibhola liphonswe = imizuzwana eyi-7.

b) Isivinini semabula uma ishaya ubuso bomhlaba

Kwaziwa:

h = -100 m (okubi ngoba ubuso bomhlaba bungaphansi kwendawo yokubhekisela noma indawo yokuqala)

v_o = 20 m/s (isiqondiso sejubane lokuqala siphezulu, ngakho-ke v_o kuyinto enhle)

g = -9.8 m/s² (isiqondiso sokusheshisa kwamandla adonsela phansi sehla, ngakho-ke u-g ungemuhle).

Okufunayo: v_t

Imibuzo nezimpendulo ezinengqondo mayelana nokunyakaza kwe-Free Fall

1. Kuyini ukunyakaza kokuwa okukhululekile?

   Ukunyakaza kokuwa okukhululekile ukunyakaza kwento ngaphansi kwethonya lamandla adonsela phansi kuphela, ngaphandle kwamanye amandla asebenzayo kuyo, njengokumelana nomoya.
2. Kuyini ukusheshisa okubangelwa amandla adonsela phansi?

   Ukusheshisa okubangelwa amandla adonsela phansi ukusheshisa okwenziwa yinto lapho iwela ngokukhululeka eduze kobuso boMhlaba. Ngokuvamile kuboniswa njengo-'g' futhi kunenani elilinganiselwa ku-9.8 m/s².

3. Iyini ifomula yokufuduka ekunyakazeni kokuwa okukhululekile, uma ubheka ijubane lokuqala nesikhathi?

   Ifomula ithi h = ut + ½gt², lapho u-h ewukufuduka (ukuphakama), u uyijubane lokuqala, u-g uyisisheshisi esibangelwa amandla adonsela phansi, kanti u-t isikhathi.
4. Ijubane lento lishintsha kanjani ngesikhathi sokunyakaza kokuwa okukhululekile?

   Ngesikhathi sokuwa okukhululekile, ijubane lento likhuphuka ngokulandelana ngokuhamba kwesikhathi ngenxa yokusheshisa okuqhubekayo kwamandla adonsela phansi.

5. Iyini ifomula yejubane lokugcina ekunyakazeni kokuwa okukhululekile, uma ubheka ijubane lokuqala nesikhathi?

   Ifomula ithi v = u + gt, lapho u-v eyisivinini sokugcina, u eyisivinini sokuqala, kanti u-g uyisivinini esibangelwa amandla adonsela phansi.
6. Kwenzekani ngejubane lento esicongweni sendlela yayo ekuhambeni kwayo ngokukhululekile?

   Esicongweni sendlela yayo, ijubane lento liba yi-zero okwesikhashana.

7. Yini emele uphawu olubi kumongo wokunyakaza kokuwa okukhululekile?

   Uphawu olungeluhle luvame ukukhomba indlela ephambene nesiqondiso esihle esikhethiwe. Kuye ngomongo, lungabonisa ukuwa phansi (uma phezulu kukuhle) noma ukuphonswa phansi (uma phezulu kukubi).
8. Kwenzekani ngokusheshisa kwento ekuweni okukhululekile lapho ifinyelela ukuphakama kwayo okuphezulu?

   Ukusheshisa kwento ekuphakameni kwayo okuphezulu ekuweni okukhululekile kuhlala kufana no-g (cishe -9.8 m/s² eduze kobuso boMhlaba), kukhomba phansi.

9. Ukumelana nomoya kuthinta kanjani ukunyakaza kokuwa kwamahhala?

   Eqinisweni, ukumelana nomoya kungalibazisa kakhulu ukwehla kwento, okwenza ukunyakaza kungasabi ukuwa ngokukhululeka. Kodwa-ke, ezinkingeni eziningi zefiziksi, ukumelana nomoya akunakwa ukuze kube lula.
10. Isikhathi sokundiza ngokunyakaza kwe-free ekwindla singakanani?

Isikhathi sokundiza yisikhathi esiphelele into echitha emoyeni. Entweni eqalisiwe futhi efika endaweni ephakeme efanayo, isikhathi sokundiza singatholakala ngefomula t = 2u/g.

Izinkinga nezixazululo mayelana nokunyakaza kokuwa kwamahhala

1. Inkinga: Idwala liwiswa edwaleni eliphakeme ngamamitha angu-78.4. Kuthatha isikhathi esingakanani ukuthi idwala lifike phansi? Isixazululo: Sisebenzisa i-equation h = ½gt². Ukuxazulula isikhathi, t = √(2h/g) = √(2×78.4/9.8) = 4 s.
2. Inkinga: Ibhola liphonswa phezulu ngesivinini sokuqala esingu-19.6 m/s. Likhuphuka kangakanani ibhola? Isixazululo: Ukusebenzisa i-equation h = v₀t – ½gt² ekuphakameni okuphezulu (lapho ijubane lokugcina lingu-0), ukuphakama h = v₀² / (2g) = (19.6)² / (2×9.8) = 20 m.
3. Inkinga: Itshe liphonswa phezulu ngesivinini sokuqala esingu-10 m/s. Ijubane lalo lizoba lingakanani ngemva kwemizuzwana emibili? Isixazululo: Isibalo v = v₀ – gt sinikeza ijubane v = 10 – 9.8×2 = -9.6 m/s.
4. Inkinga: Uhlamvu lwemali luwela emthonjeni bese luwela emanzini ngemva kwemizuzwana emi-3. Ujule kangakanani umthombo? Isixazululo: Ukusebenzisa i-h = ½gt², ukujula kwe-h = ½x9.8×3² = 44.1 m.
5. Inkinga: Incwadi iwela etafuleni bese ishaya phansi ngemva kwemizuzwana engu-0.5. Itafula laliphakeme kangakanani? Isixazululo: Ukusebenzisa i-h = ½gt², ukuphakama i-h = ½x9.8x(0.5)² = 1.225 m.
6. Inkinga: Ibhola liphonswa phezulu ngesivinini sokuqala esingu-20 m/s. Lizofika nini ekuphakameni kwalo okuphezulu? Isixazululo: Ekuphakameni okuphezulu, v = 0. Ukuxazulula u-t = (v – v₀) / -g, isikhathi u-t = (0 – 20) / -9.8 = 2.04 s.
7. Inkinga: Into iwela imizuzwana eyi-6. Ingakanani ijubane layo lokugcina? Isixazululo: Ukusebenzisa i-v = v₀ + gt ngesivinini sokuqala i-v₀ = 0, isivinini sokugcina i-v = 0 + 9.8×6 = 58.8 m/s.
8. Inkinga: I-apula liwa esihlahleni futhi kuthatha imizuzwana eyi-1.5 ukushayisa phansi. Bekungakanani ukuphakama kwesihlahla? Isixazululo: Ukusebenzisa i-h = ½gt², ukuphakama i-h = ½x9.8x(1.5)² = 11 m.
9. Inkinga: Ibhola lezinyawo likhahlelwa phezulu phezulu ngesivinini sokuqala esingu-25 m/s. Isikhathi esingakanani ngaphambi kokuba lishaye phansi? Isixazululo: Isikhathi sokufinyelela ukuphakama okuphezulu t = v₀ / g = 25 / 9.8 = 2.55 s. Isikhathi esiphelele sokushaya phansi siphindwe kabili kulokhu, ngakho t = 2×2.55 = 5.1 s.
10. Inkinga: Itshe liwela ebhulohweni bese liwela emanzini ngemva kwemizuzwana emi-4. Liphakeme kangakanani ibhuloho? Isixazululo: Ukusebenzisa i-h = ½gt², ukuphakama i-h = ½x9.8×4² = 78.4 m.
11. Inkinga: Irokhethi idutshulwa iqonde phezulu ngesivinini esingama-50 m/s. Ikhuphuka kangakanani? Isixazululo: Ukusebenzisa i-h = v₀² / (2g), ukuphakama i-h = (50)² / (2×9.8) = 127.55 m.
12. Inkinga: Ibhola liphonswa phansi ngesivinini sokuqala esingu-10 m/s. Lingakanani ijubane lalo ngemva kwemizuzwana emi-2? Isixazululo: Ukusebenzisa i-v = v₀ + gt, ijubane i-v = 10 + 9.8×2 = 29.6 m/s.
13. Inkinga: Ibhola liphonswa phezulu phezulu bese libuyela phansi ngemizuzwana eyi-6. Lalingakanani ijubane lalo lokuqala? Isixazululo: Ukusebenzisa i-v₀ = gt / 2 (njengoba isikhathi esiphelele siphindwe kabili isikhathi sokufinyelela ukuphakama okuphezulu), ijubane lokuqala i-v₀ = 9.8×6 / 2 = 29.4 m/s.
14. Inkinga: Into iwela imizuzwana eyi-10. Iwela ibanga elingakanani? Isixazululo: Ukusebenzisa i-h = ½gt², ibanga i-h = ½x9.8×10² = 490 m.
15. Inkinga: Imabula iwa embhoshongweni futhi kuthatha imizuzwana emi-5 ukuthi ishayeke phansi. Iphakeme kangakanani le mbhoshongo? Isixazululo: Ukusebenzisa i-h = ½gt², ukuphakama i-h = ½x9.8×5² = 122.5 m.
16. Inkinga: Ibhola le-baseball liphonswa phezulu phezulu ngesivinini sokuqala esingu-15 m/s. Lizofika nini ekuphakameni kwalo okuphezulu? Isixazululo: Ekuphakameni okuphezulu, v = 0. Ukuxazulula u-t = (v – v₀) / -g, isikhathi u-t = (0 – 15) / -9.8 = 1.53 s.
17. Inkinga: Into iyawa bese iwela imizuzwana eyi-7. Iyini ijubane layo lokugcina? Isixazululo: Ukusebenzisa i-v = v₀ + gt ngesivinini sokuqala i-v₀ = 0, isivinini sokugcina i-v = 0 + 9.8×7 = 68.6 m/s.
18. Inkinga: Itshe liphonswa phezulu ngesivinini sokuqala esingu-30 m/s. Ijubane lalo lizoba yini ngemva kwemizuzwana emi-3? Isixazululo: Ukusebenzisa i-v = v₀ – gt, ijubane v = 30 – 9.8×3 = 0.6 m/s.
19. Inkinga: Itshe liwiswa edwaleni bese liwela phansi ngemva kwemizuzwana engu-8. Liphakeme kangakanani idwala? Isixazululo: Ukusebenzisa i-h = ½gt², ukuphakama i-h = ½x9.8×8² = 313.6 m.

20. Inkinga: Umcibisholo udutshulwa uqonde phezulu ngesivinini esingamamitha angu-60 ngomzuzwana. Kuthatha isikhathi esingakanani ngaphambi kokuba ushaye phansi? Isixazululo: Isikhathi sokufinyelela ukuphakama okuphezulu t = v₀ / g = 60 / 9.8 = 6.12 s. Isikhathi esiphelele sokushaya phansi siphindwe kabili kulokhu, ngakho t = 2×6.12 = 12.24 s.