Molao oa Bobeli oa Newton ke o mong oa mehopolo ea motheo fisiks e laolang kamano pakeng tsa matla, boima le ho potlaka. Molao ona o re ho potlaka ha ntho ho lekana le matla a sebele a sebetsang ho eona 'me ho lekana le boima ba eona ka tsela e fapaneng. Ho ea ka lipalo, Molao oa Bobeli oa Newton o boleloa e le:
\[ F = ma \]
Di mana:
– \( F \) ke matla a letlooa a sebetsang nthong (ho Newtons, N).
– \( m \) ke boima ba ntho (ka dikhilogram, kg).
– \( a \) ke ho potlaka ha ntho (ka dimithara ka motsotsoana, \( m/s^2 \)).
Sehloohong sena, re tla tšohla mehlala e meng ea Molao oa Bobeli oa Newton ho utloisisa ts'ebeliso ea oona maemong a fapaneng.
Mohlala oa Potso ea 1: Qobella Koloi e Potlakisang
Potso:
Koloi e boima ba 1000 kg e potlakisa ho tloha phomolong ho ea lebelong la 20 m/s ka metsotsoana e 5. Bala matla a hlokahalang ho fihlella lebelo lena.
Tharollo:
Taba ea pele, re hloka ho bala lebelo la koloi. Ho potlakisa (\( a \)) ho ka baloa ho sebelisoa foromo:
\[ a = \frac{\Delta v}{\Delta t} \]
Di mana:
– \(\Delta v\) ke phetoho ya lebelo.
– \(\Delta t\) ke phetoho ya nako.
Kenya mekhoa e tsebahalang sebakeng sa eona:
\[ a = \frac{20 \, \text{m/s} – 0 \, \text{m/s}}{5 \, \text{seconds}} \]
\[ a = \frac{20 \, \text{m/s}}{5 \, \text{seconds}} \]
\[ a = 4 \, \mongolo{m/s}^2 \]
Jwale, re ka bala matla a hlokahalang re sebedisa Molao wa Bobedi wa Newton:
\[ F = ma \]
\[ F = (1000 \, \text{kg})(4 \, \text{m/s}^2) \]
\[ F = 4000 \, \mongolo{N} \]
Kahoo, matla a hlokahalang ho potlakisa koloi ke 4000 N.
Mohlala oa Potso ea 2: Matla a ho Fetoha ha Lebokose
Potso:
Lebokose le boima ba 50 kg le sutumelletsoa holim'a sebaka se bataletseng ka matla a 300 N. Haeba matla a khohlano pakeng tsa lebokose le bokaholimo e le 100 N, bala lebelo la lebokose.
Tharollo:
Taba ea pele, re bala matla a letlooa a sebetsang lebokoseng. Matla a letlooa (\( F_{\text{net}} \)) ke matla a felletseng a sebetsang nthong ka mor'a ho nahana ka matla 'ohle a sebetsang ho eona, ho kenyeletsoa le khohlano.
\[ F_{\text{net}} = F_{\text{push}} – F_{\text{friction}} \]
\[ F_{\text{net}} = 300 \, \text{N} – 100 \, \text{N} \]
\[ F_{\text{net}} = 200 \, \text{N} \]
Jwale, re ka bala ho potlaka ha lebokose re sebedisa Molao wa Bobedi wa Newton:
\[ F_{\text{net}} = ma \]
\[ 200 \, \mongolo{N} = (50 \, \mongolo{kg})a \]
\[ a = \frac{200 \, \text{N}}{50 \, \text{kg}} \]
\[ a = 4 \, \mongolo{m/s}^2 \]
Kahoo, lebelo la lebokose ke 4 m/s².
Mohlala oa Potso ea 3: Ho Bala Matla a Hlokahalang ho Phahamisa Moroalo
Potso:
Kreineng e phahamisa mojaro o boima ba 200 kg ho ya hodimo ka lebelo la 1,5 m/s². Bala matla a hlokahalang ke kreineng ho phahamisa mojaro.
Tharollo:
Taba ea pele, re hloka ho bala matla a khoheli a sebetsang holim'a mojaro. Matla a khoheli (\( F_g \)) a ka baloa ho sebelisoa foromo:
\[ F_g = mg \]
Di mana:
– \( g \) ke ho potlaka ho bakwang ke matla a khoheli (\( 9,8 \, \text{m/s}^2 \)).
Kenya mekhoa e tsebahalang sebakeng sa eona:
\[ F_g = (200 \, \text{kg})(9,8 \, \text{m/s}^2) \]
\[ F_g = 1960 \, \mongolo{N} \]
Jwale, re bala matla ohle (\( F \)) a hlokahalang ke crane ho phahamisa mojaro re nahanne ka ho potlakisa ho eketsehileng:
\[ F = ma + F_g \]
\[ F = (200 \, \text{kg})(1,5 \, \text{m/s}^2) + 1960 \, \text{N} \]
\[ F = 300 \, \mongolo{N} + 1960 \, \mongolo{N} \]
\[ F = 2260 \, \mongolo{N} \]
Kahoo, matla a hlokahalang ke crane ho phahamisa mojaro ke 2260 N.
Mohlala Bothata ba 4: Matla Tsamaisong ea Lintho tse peli tse hokahantsoeng ke Thapo
Potso:
Lintho tse peli tse boima ba 10 kg le 20 kg ka ho latellana li hokahantsoe ka thapo e bobebe 'me li leketlile ho pulley. Bala ho potlaka ha sistimi le khatello e teng thapong ha sistimi e lokolloa phomolong.
Tharollo:
Sa pele, ha re hlaloseng matla a sebetsang linthong ka bobeli. A re bitseng bongata \( m_1 = 10 \, \text{kg} \) le bongata \( m_2 = 20 \, \text{kg} \). Matla a khoheli a sebetsang linthong ka bobeli ke:
\[ F_{g1} = m_1 g = (10 \, \text{kg})(9,8 \, \text{m/s}^2) = 98 \, \text{N} \]
\[ F_{g2} = m_2 g = (20 \, \text{kg})(9,8 \, \text{m/s}^2) = 196 \, \text{N} \]
Kaha sistimi e lokollotsoe phomolong, ho potlaka ha sistimi ho ka baloa ho sebelisoa Molao oa Bobeli oa Newton. Potlako eohle (\( a \)) ea sistimi ke:
\[ (m_1 + m_2)a = F_{g2} – F_{g1} \]
\[ (10 \, \text{kg} + 20 \, \text{kg})a = 196 \, \text{N} – 98 \, \text{N} \]
\[ 30 \, \text{kg} \cdot a = 98 \, \text{N} \]
\[ a = \frac{98 \, \text{N}}{30 \, \text{kg}} \]
\[ a = 3,27 \, \mongolo{m/s}^2 \]
Jwale, re bala kgatello e thapong (\( T \)). Kgatello e thapong e ka balwa ho sebediswa Molao wa Bobedi wa Newton hodima e nngwe ya di-mass, mohlala \( m_1 \):
\[ T – m_1 g = m_1 a \]
\[ T – 98 \, \text{N} = (10 \, \text{kg})(3,27 \, \text{m/s}^2) \]
\[ T – 98 \, \mongolo{N} = 32,7 \, \mongolo{N} \]
\[ T = 32,7 \, \mongolo{N} + 98 \, \mongolo{N} \]
\[ T = 130,7 \, \mongolo{N} \]
Kahoo, ho potlaka ha sistimi ke 3,27 m/s² mme kgatello thapong ke 130,7 N.
Qetello
Ka mehlala e fapaneng ea Molao oa Bobeli oa Newton, re ithutile kamoo molao-motheo ona o sebelisoang kateng ho bala matla, ho potlaka le khatello ea maikutlo maemong a fapaneng. Molao oa Bobeli oa Newton ha o bohlokoa feela fisiks ea khopolo-taba empa hape o na le lits'ebetso tse ngata tse sebetsang bophelong ba letsatsi le letsatsi le theknoloji. Ka ho utloisisa le ho sebelisa Molao oa Bobeli oa Newton, re ka rarolla mathata a fapaneng a mechini ka katleho le ka nepo.
